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    • 专利摘要:
    A method for establishing communications between a master unit and a plurality of node units. Of the plurality of node units, K node units are assumed to have established communications with a master unit. A first (K+1) node unit of the plurality of node units, desires to establish communications with the master unit. The method includes transmitting from the master unit, a base-station spread spectrum signal having a common signalling chip code, transmitting from the first node unit a second spread spectrum signal with a first identification code using the common-signalling chip code, transmitting from the master unit a third spread spectrum signal with a master unit identification code, using the common-signalling chip code. The method further includes generating at the first node unit using the master unit identification signal, a master unit chip code for transmitting spread spectrum signals to the master unit. Additionally, the method includes generating, at the master unit using the first identification code, a first node unit chip code for transmitting spread spectrum signals to the first node unit.
    公开号:US20010000136A1
    申请号:US09/731,329
    申请日:2000-12-05
    公开日:2001-04-05
    发明作者:Robert Dixon；Jeffrey Vanderpool
    申请人:Dixon Robert C.；Vanderpool Jeffrey S.；
    IPC主号:H04B7-2628
    专利说明:
    [1] 1. This invention relates to spread spectrum communications, and more particularly to a method for establishing spread spectrum communications between a base station and a handset. DESCRIPTION OF THE PRIOR ART
    [2] 2. A spread spectrum system is one in which the signal energy is distributed over a frequency spectrum that is much wider than the maximum bandwidth required to transmit the information being sent. Techniques for direct sequence spread spectrum modulation have been developed for several years to ensure, among other benefits, secure communications. Modulation is achieved by mixing the information to be sent with a periodic pseudo-noise (PN) code. The spectral density function for the resulting signal has a sin(X)/X shape with a very wide bandwidth, as compared to the information, and a lower spectral density function amplitude as compared to the information. This modification of the original spectral density function reduces the signal's sensitivity to in-band interference and jamming, as well as reducing interference to other equipment that is sensitive to radio frequencies. Among the other advantages inherent to a spread spectrum system are selective addressing capabilities, code division multiplexing for multiple access, and highly accurate ranging capabilities.
    [3] 3. Due to the encoded nature of the signal, demodulation is a more involved process compared with demodulation schemes associated with traditional communications systems. In this case, demodulation involves a receiver reference code, identical to that transmitted, that synchronizes the receiver with the transmitter. The difficulty with this process is that there is no indication of the degree of non-synchronization between received and reference codes until a very high degree of synchronization is achieved. Additionally, mismatches between transmit and receive oscillators used to generate PN codes tend to cause drift in the synchronization between transmitter and receiver.
    [4] 4. A prior art communications system using spread spectrum for a wireless private branch exchange (PBX) is described in U.S. Pat. No. 4,672,658 to Kavehrad et al., issued Jun. 9, 1987, which is incorporated herein by reference. Kavehrad et al. relate to a wireless PBX network wherein direct sequence spread spectrum multiple access is used for voice and data communications to support a plurality of local-local and local-external communications. The PBX network includes a plurality of local user transceivers using a first unique chip sequence pattern for information communication and a second common chip sequence pattern for call set up, and a central PBX having a plurality of PBX transceivers using corresponding chip sequence patterns.
    [5] 5. The prior art does not teach a method for establishing spread spectrum communications using a spread spectrum signal which allows the use of one or more common signalling spectrum spreading codes to manage handshaking from a master unit to a plurality of node units, without the use of a separate frequency channel for common signalling, and without requiring a separate time channel for common signalling. OBJECTS OF THE INVENTION
    [6] 6. An object of the invention is to provide a method for establishing communications using spread spectrum signals to communicate between a master unit and a plurality of remote units.
    [7] 7. Another object of the invention is to provide for a method for using spread spectrum signals to communicate between a master unit and a plurality of remote units requiring a minimum amount of digital signal processing.
    [8] 8. A further object of the invention is to allow use of the same frequency for both common signalling as well as communications.
    [9] 9. An additional object of the invention is to allow use of the same frequency and same time slot for both common signalling and communications.
    [10] 10. Another object of the invention is to allow access and handshaking of a plurality of node units to a single master unit when no node unit has a-priori knowledge of spectrum spreading or identification codes, time slots, synchronization parameters, or frequencies utilized at the master unit to be accessed.
    [11] 11. A still further object of the invention is to allow use of a collision avoidance protocol.
    [12] 12. Another object of the invention is to allow the management of simultaneous users on a single master unit on a common signalling and communication time slot and frequency basis.
    [13] 13. Another object of the invention is to allow the node units to have a minimal need for intelligence, processing power, or local synchronized clock sources.
    [14] 14. Another object of the invention is to allow the option for using spectrum spreading codes as address codes.
    [15] 15. Another object of the invention is to allow node response to a valid signal within a time slot through CDMA, eliminating the need for a highly accurate clock and a level of node complexity and intelligence.
    [16] 16. A still further object of the invention is to allow for M-ary data transmission to simplify transceiver complexity in remote mode units.
    [17] 17. An additional object of the invention is to allow for a network of master units, each communicating with a multiplicity of node units, in a grid which requires only three frequencies in a frequency division multiplex operation.
    [18] 18. Another object of the invention is to allow half-duplex communication between master unit and node unit in the same TDMA time slot. SUMMARY OF THE INVENTION
    [19] 19. According to the present invention as embodied and broadly described herein, a method and apparatus for establishing and maintaining handshaking and communications between a master unit and a plurality of N node units, with multiple configurations, is provided. Of the plurality of N node units, K node units, where K<N, are assumed to have established 2K communications links with a master unit, using up to 2K different spectrum spreading codes to generate up to K different spread spectrum signals to transmit from the master unit to K node units, and K different spread spectrum signals to transmit from K node units to the master unit. A time slot for each of the K linked node units is provided for transmitting and receiving in each of the first K time slots. A total of N time slots, constituting a time frame, are assumed available for communicating and/or initializing communications with the master unit by using time division multiple access. While system capacity allows N node units to establish and maintain simultaneous communications, with a single master unit, the number of node units, X, which may access the master unit is not limited to N, but may be much greater.
    [20] 20. In this invention, transmitting and/or receiving in a time slot may include transmitting and/or receiving in a plurality of time slots in a slot position within a frame and/or from frame to frame. Transmitting and/or receiving in a particular time slot also does not limit a time slot to a particular slot position within a frame.
    [21] 21. A first node unit, i.e. the (K+1)th node unit, of the plurality of the N node units, of the plurality of X node units able to access the master unit, is assumed to desire to establish communications with, or access, the master unit. The method constitutes handshaking between the (K+1)th node unit and the master unit in an access time slot.
    [22] 22. A first embodiment of the present invention implements the (K+1)th time slot as the access slot and (K+1)th communication slot. The (K+1)th time slot may occupy, or float to, any open time slot within the time frame of the N-K open slots, and may change time slots as the number, K, of node units which have established communications links with the master unit, changes. This embodiment comprises several steps, the first of which is transmitting in a (K+1)th time slot from the master unit a master-initialization spread spectrum signal, CSn1, common to the plurality of X node units.
    [23] 23. In response to receiving the master-initialization spread spectrum signal, CSn1, in the (K+1)th time slot, the (K+1)th node unit transmits in the (K+1)th time slot a first node-initialization spread spectrum signal, CSm1, which may be the same as, and thus a node retransmission of, the master-initialization spread spectrum signal, CSn1, or which may be a spread spectrum signal having a chip code distinct from the master-initialization spread spectrum signal, CSn1, and common to all master units that the (K+1)th node unit may access. The first node-initialization spread spectrum signal, CSm1, may contain the (K+1)th node unit's identification code as data information modulating the chip sequence for the (K+1)th node-initialization spread spectrum signal.
    [24] 24. The master unit receives the first node-initialization spread spectrum signal, CSm1, from the (K+1)th node unit in the (K+1)th time slot, and, in reply, transmits in the (K+1)th time slot a master-identification spread spectrum signal, CSn2, which may be distinct from spread spectrum signal CSn1 but common to all X node units. The master-identification spread spectrum signal contains the master unit's (K+1)th slot identification code as data information modulating the chip sequence for the master-identification spread spectrum signal.
    [25] 25. In response to receiving the master-identification spread spectrum signal, CSn2, the (K+1)th node unit may transmit in the (K+1)th time slot a second node-initialization spread spectrum signal, CSm2. The second node-initialization spread spectrum signal, CSm2, may contain (K+1)th node-identification code as data information modulating the chip sequence from the node-initialization spread spectrum signal. The node-identification spread spectrum signal may have a high degree of uniqueness to the plurality of the N−1 other node units.
    [26] 26. The master unit receives the (K+1)th node unit's identification code, and transmits in the (K+1)th time slot a master unit (K+1)th slot communication spread spectrum signal, CMNk+1, generated from a spectrum spreading code derived from the (K+1)th node unit's identification code.
    [27] 27. In response to receiving the (K+1)th master identification code in the (K+1)th time slot from the master unit the (K+1)th node unit transmits in the (K+1)th time slot a (K+1)th node unit communication spread spectrum signal, CNMk+1, generated from a spectrum spreading code derived from the (K+1)th master-identification code.
    [28] 28. If all node units utilize the same receive spread spectrum code (CMNk+1), the master unit does not necessarily have to derive a spectrum spreading code from the (K+1)th node unit's identification code, but may rather, upon determination by the master unit that the (K+1)th node unit's identification code is valid, transmit a spread spectrum communication signal common to all node units able to access the master unit and rely on address bits within the time slot to maintain synchronization of the node units with the master unit.
    [29] 29. In a second embodiment of the present invention, a fixed, or Fth, time slot, such as the 1st or Nth slots of the plurality of N time slots in a time frame, serves as the access slot. The second embodiment comprises of the steps of transmitting in the Fth time slot from the master unit a master-initialization spread spectrum signal, CSn1, common to all node units. The Fth time slot may occupy a fixed time slot within the time frame of the N-K unused time slots, and does not change slots as the number, K, of node units which have established communications links with the master unit, changes.
    [30] 30. In response to receiving the master-initialization spread spectrum signal, CSn1, in the Fth time slot, the (K+1)th node unit transmits in the Fth time slot a first and second node-initialization spread spectrum signal, chiasm, CSm2, having the characteristics and properties previously discussed.
    [31] 31. The master unit receives the node-initialization spread spectrum signal, CSm, in the Fth time slot from the (K+1)th node unit, and transmits in the Fth time slot a master-identification spread spectrum signal, CSn2, which may be distinct from the master-initialization spread spectrum signal, CSn1, but common to all X node units, and containing the master unit's (K+1)th slot identification code. The master-identification spread spectrum signal, CSn2, may include information directing the (K+1)th node unit as to which time slot and spectrum spreading code to use for communication from the (K+1)th node unit to the master unit.
    [32] 32. In response to receiving the master-identification spread spectrum signal, CSn2, the (K+1)th node unit transmits in the Fth time slot the second node-initialization spread spectrum signal, CSm2. The second node-initialization spread spectrum signal, CSm2, is common to all master units that (K+1)th node unit may access, and may contain its (K+1)th node-unit-identification code. The second node-initialization spread spectrum signal, CSm2, may have a high degree of uniqueness to the plurality of the N−1 other node units.
    [33] 33. The master unit receives the (K+1)th node unit's identification code from the (K+1)th node unit in the Fth time slot, and transmits in the (K+1)th time slot a master unit (K+1)th slot communication spread spectrum signal, CMNk+1, generated from a spectrum spreading code derived from the (K+1)th node unit's identification code.
    [34] 34. In response to receiving the (K+1)th master unit identification code from the master unit in the Fth time slot via the CSn2 spread spectrum signal, the (K+1)th node unit transmits in the (K+1)th time slot a (K+1)th node unit communication spread spectrum signal, CNMk+1, generated from a spectrum spreading code derived from the (K+1)th master unit identification code.
    [35] 35. If all node units utilize the same receive spread spectrum code (CMNk+1), the master unit does not necessarily have to derive a spectrum spreading code from the (K+1)th node unit's identification code, but may rather, upon determination by the master unit that the (K+1)th node unit's identification code is valid, transmit a spread spectrum communication signal common to all node units able to access the master unit and rely on address bits within the time slot to maintain synchronization of the node units with the master unit.
    [36] 36. As an alternative architecture in this configuration, the (K+1)th node unit may transmit the (K+1)th node unit communication spread spectrum signal in the (K+1)th time slot in response to receiving the master unit (K+1)th slot communication signal in the (K+1)th time slot. In this case, the master unit (K+1)th slot identification signal transmitted in the Fth time slot would not necessarily contain information detailing which time slot of the N-K time slots to use for communication transmissions.
    [37] 37. In a third embodiment of the invention, the master unit may function with the initialization, identification, and communication protocols detailed in first and second embodiments, but may be configured to transmit the master-initialization spread spectrum signal, CSn1, in a plurality of vacant (N-K) time slots. If the master unit does transmit in a plurality of vacant (N-K) time slots, then node units (K+1), (K+2), (K+3), . . . , (K+(N-K)) (or N) may access the master unit in the (K+1)th, (K+2)th, (K+3)th, . . . , (K+(N-K))th (or Nth) time slots, respectively or randomly. Therefore, the (K+1)th node unit trying to access the master unit would access the first time slot immediately available after its initiation of the access attempt, instead of waiting for the (K+1)th or Fth time slot to occur in the next frame.
    [38] 38. Thus, if K users are present, the master unit transmits in the 1st through Kth time slots the master unit communication spread spectrum signals, CMN1 through CMNk, pertaining to the 1st through Kth node units, and in the (K+1)th through Nth time slots a master-initialization spread spectrum signal, CSn1, which is common to the plurality, X, of node units that may access the master unit. The master-initialization spread spectrum signal may be distinct from all master or node unit communication and identification spread spectrum signals.
    [39] 39. In all three embodiments, if a plurality of up to N-K node units tries to access the master unit sequentially in time, with the period between access attempts being greater than or equal to the slot period, upon reception of the master-initialization spread spectrum signal, CSn1, each node unit will access the open time slot available immediately following its initiation of the access attempt. When the first (K+1)th node unit has accessed the master unit (master unit slot and (K+1)th node unit identification signals are being transmitted in the (K+1)th time slot), the master unit may wait to transmit the (K+2)th through Nth master-identification signals until the (K+1)th slot is occupied with master unit-to-(K+1)th node unit and/or (K+1)th node unit-to-master unit communication signals.
    [40] 40. If a plurality of up to N-K node units tries to access the master unit instantaneously (the time period between node unit access attempts being less than the slot period), upon reception of the master-initialization spread spectrum signal, CSn1, each node unit of this plurality of node units will transmit a node-initialization spread spectrum signal, CSm, within the same time slot, thus jamming at least one of the node-initialization spread spectrum signals, CSm, at the master unit. If the master unit does not receive a valid node-initialization spread spectrum signal, CSm, or identification code from a node unit during the time slot, it may cease to transmit any signal in that time slot for a predetermined period of time, or it may transmit a “jammed signal alarm” code through the master unit slot identification signal, CSn2. When a lack of response or a jammed signal alarm code from the master unit is encountered, the node units which tried to access the master unit instantaneously, of the plurality, N-K, of node units, may initiate a node unit internal “wait” state, whose period may be derived from each node unit's identification code. After the wait state period, the plurality of node units which failed to access the master unit may attempt to access it again. Since wait states may be highly unique to each node unit, it is unlikely that the same plurality of node units will jam each other again.
    [41] 41. If all N time slots are being used for communication or initialization functions by N node units, then the master-initialization spread spectrum signal, CSn1, is not transmitted by the master unit, and no new node units of the plurality of X-N node units may access the master unit. The master unit may operate such that the Nth time slot may transmit a “busy” alarm to the plurality of N-K node units having not established communications with the master unit such that it informs them that no further access is available at that master unit, thereby allowing only N−1 node units to access the master unit.
    [42] 42. Additional objects of the inventions and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. The objects and advantages of the invention also may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS
    [43] 43. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention, and together with the description serve to explain the principles of the invention.
    [44] 44.FIG. 1 illustrates a master unit with a plurality of remote units;
    [45] 45.FIGS. 2A and 2B illustrate the protocol of the method of the present invention;
    [46] 46.FIG. 3 illustrates time slots;
    [47] 47.FIG. 4 illustrates the multiple access system timing diagram of a preferred embodiment using binary signalling techniques;
    [48] 48.FIG. 5 illustrates the multiple access system timing diagram of a second preferred embodiment using M-ary signalling techniques; and
    [49] 49.FIG. 6 illustrates an FDMA three frequency master unit network. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
    [50] 50. Reference will now be made to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.
    [51] 51. The invention disclosed in this patent is related to the inventions disclosed in U.S. Patent Application entitled “Spread Spectrum Correlator,” by Robert C. Dixon and Jeffrey S. Vanderpool and having Ser. No. 07/390,315 and Filing Date of Aug. 7, 1989; and in U.S. Patent Application entitled “Asymmetric Spread Spectrum Correlator,” by Robert C. Dixon and Jeffrey S. Vanderpool and having Ser. No. 07/389,914 and Filing Date of Aug. 7, 1989, which are expressly incorporated herein by reference.
    [52] 52. In the exemplary arrangement shown in FIG. 1, the present invention includes a method and apparatus for establishing communications between a master unit 50 and N node units. The master unit 50 may be a base station, PBX, file server or other central controlling device serving as the center of a star network, and the node units may be any type of computer, communications, telephone, video or other data device serving as a node point in the star network. While the system capacity allows N node units to establish simultaneous communications with a single master unit, the number, X, of node units that may access the master unit is not limited to N node units, but may be much larger than N.
    [53] 53. As illustratively shown in FIG. 1, a master unit 50 is shown with a plurality of N node units 51, 52, 53, 54, 55, where N=5, and a plurality of X node units 56, of which the plurality of N node units is a subset. Of the plurality of N node units 51, 52, 53, 54, 55, three node units (K=3), are assumed to already have established communications channels with the master unit 50 using up to six different spectrum spreading chip codes to generate up to six different spread spectrum signals.
    [54] 54. A particular node unit and master unit use two of up to six spectrum spreading chip codes during communications. A first of the two spectrum spreading chip codes is used while communicating from the master unit to the particular node unit. A second of the two spectrum spreading chip codes is used while communicating from the particular node unit to the master unit. The spectrum spreading chip codes may be embodied as a pseudo-random sequence, and the spectrum spreading chip codes typically modulate information data which may be embodied as a data bit sequence, as is well known in the art.
    [55] 55. A total of five time slots (N=5), which constitute a time frame, are assumed available for communicating with the master unit by use of time division multiple access. Each of the three node units 51, 52, 53, communicates with the master unit 50 in a time slot, which may be the first three of five time slots. Alternatively, each of the three node units may communicate with the master unit 50 in three time slots which have any predetermined order. Additionally, a (K+1)th time slot, which by way of example is the fourth time slot (K+1=4), may occupy, or “float” to, any open time slot within the time frame of the two unused time slots, and may change time slots as the number, K, of node units which have established communications links with the master unit, changes. A node unit, which of the five node units is the fourth node unit, desires to establish communications with, or access the master unit 50.
    [56] 56. In the present invention, transmitting and/or receiving in a time slot may include transmitting and/or receiving in a plurality of time slots in a slot position within a frame and/or from frame to frame. Transmitting and/or receiving in a particular time slot also does not limit a time slot to a particular slot position within a frame.
    [57] 57. In a first embodiment of the invention, the apparatus and method comprises the steps of transmitting in a (K+1)th time slot from the master unit 50, a master-initialization spread spectrum signal, CSn1. The master-initialization spread spectrum signal uses a master-common-signalling chip code which is known and stored in all the node units able to access the master unit. All of the node units have means responsive to the master-initialization spread spectrum signal, for correlating with the master-common-signalling chip code of the master unit 50. The correlating means may be embodied as a surface acoustic wave device (SAW), digital device, or any other device which can perform the required function. The master-common-signalling chip code may, but is not required to, modulate information data embodied as a data bit sequence or data symbol sequence. The information data may include indexing, addressing, or other data pertinent to the (K+1)th time slot. The entire chip sequence of the master-common-signalling chip code may be transmitted per data bit or data symbol during the (K+1)th time slot from the master unit.
    [58] 58. In response to receiving the master-initialization spread spectrum signal, CSn1, at the (K+1)th node unit, the method and apparatus include transmitting from the (K+1)th node unit in the (K+1)th time slot a first node-initialization spread spectrum signal, CSm1. The first node-initialization spread spectrum signal may, but is not required to, retransmit the master-common-signalling chip code which was transmitted from the master unit during the (K+1)th time slot. Alternatively, the first node-initialization spread spectrum signal, CSm1, may use a node-common-signalling chip code which can be received by all master units that the (K+1)th node unit may access. The first node-initialization spread spectrum, CSm1, signal additionally may be modulated by information data, such as the (K+1)th node unit's identification code, or an acknowledgment (“ack”) to signal the master unit a node unit desires to establish communications with the master unit, allowing the master to proceed with the exchange of identification and communication information between the master unit an the (K+1)th node unit. The entire chip sequence of the master-common-signalling chip code or node-common-signalling chip code may modulate each bit, or symbol, of the information data, i.e., the node unit's identification code, using spread spectrum modulation.
    [59] 59. The master unit 50 receives the first node-initialization spread spectrum signal, CSm1, from the (K+1)th node unit in the (K+1)th time slot, and transmits in the (K+1)th time slot a master-identification spread spectrum signal, CSn2. The master-identification spread spectrum signal uses a master-identification code which is common to all X node units. The master-identification code is modulated by the master-common-signalling chip code or node common-signalling chip code to produce the master-identification spread spectrum signal.
    [60] 60. The master-identification code may be unique to the (K+1)th master unit slot, and may be unique to a minimum of N master-identification codes available at the master unit 50. The master-identification code, which may be distinct from all other master-identification codes and node-identification codes, is used by the node unit for generating a master unit chip code for a spread spectrum signal used to communicate with the master unit 50. The master-unit chip code is generated from an algorithm processing the master-identification code, which may include, for example, a one-to-one relationship for setting taps on a set of shift registers.
    [61] 61. In response to receiving the master-identification spread spectrum signal, CSn2, from the master unit 50 in the (K+1)th time slot, the (K+1)th node unit transmits in the (K+1)th time slot a (K+1) node-identification code to the master unit using a second node-initialization spread spectrum signal, CSm2. As described previously for the first node-initialization spread spectrum signal, the second node-initialization spread spectrum signal, CSm2, uses a master-common-signalling chip code, or a node-common-signalling chip code which is common to all master units to which the (K+1) node unit may access for modulating the node-identification code. The (K+1) node-identification code may have a high degree of uniqueness compared with node unit identification codes by which the plurality of other node units may access the master unit.
    [62] 62. The master unit 50 receives the (K+1)th node-identification code, and establishes the master-unit-to-(K+1)th-node-unit communication channel by transmitting in the (K+1)th time slot a master-unit-(K+1)th-slot communication spread spectrum signal, CMNK+1. A (K+1)-node-unit chip code for the master unit-(K+1)th slot communication spread spectrum signal may be generated from the (K+1)th node unit identification code.
    [63] 63. In response to receiving the (K+1)th master-identification code, the (K+1)th node unit establishes the (K+1)th node-unit-to-master unit communication channel by transmitting in the (K+1)th time slot a (K+1)th node-unit-communication spread spectrum signal, CNMK+1. A master-unit chip code for the (K+1)th node unit communication spread spectrum signal is generated from the (K+1)th master-identification code.
    [64] 64. In the explanatory embodiment discussed herein, the master unit may operate such that it does not transmit in a time slot except to send a plurality of K master unit slot communication spread spectrum signals, CMN1 to CMNK, in K time slots, to K node units which have established communications links with the master unit, plus a master-initialization spread spectrum signal, CSn1, in the case of a search for a new node unit trying to access the master unit, or a master unit slot identification signal, CSn2, in the case of a node unit being in the process of accessing a master unit, leaving N-K-1 time slots unused. If the master unit is transmitting a master-identification spread spectrum signal, CSn2, in the (K+1)th time slot (the (K+1)th node unit is in the process of accessing the master unit), it then may transmit a master-initialization spread spectrum signal, CSn1, in the (K+2)th time slot, in order to allow the (K+2)th node unit to access the master unit through the same method.
    [65] 65. If all node units utilize the same receive spread spectrum code (CMNk+1), the master unit does not necessarily have to derive a spectrum spreading code from the (K+1)th node unit's identification code, but may rather, upon determination by the master unit the (K+1)th node unit's identification code is valid, transmit a spread spectrum communication signal common to all node units able to access the master unit and rely on address bits within the time slot to maintain-synchronization of the node units with the master unit.
    [66] 66. If a plurality of up to N-K node units tries to access the master unit sequentially in time, with the period between access attempts being greater than or equal to the time frame period, upon reception of the master-initialization spread spectrum signal, CSn1, each node unit of the plurality of N-K node units will access the time slot immediately available following its initiation of the access attempt. When the first (K+1)th node unit has accessed the master unit (master unit (K+1)th slot and (K+1)th node unit identification signals are being transmitted in the (K+1)th time slot), the master unit may wait to transmit the (K+2)th master unit slot identification signal until the (K+1)th slot is occupied with master unit-to-(K+1)th node unit and/or (K+1)th node unit-to-master unit communication signals.
    [67] 67. If a plurality of up to N-K node units tries to access the master unit instantaneously (the time period between node unit access attempts being less than the frame period), upon reception of the master-initialization spread spectrum signal, CSn1, each node unit of this plurality of node units will transmit a first node initialization spread spectrum signal, CSm1, within the same time slot, thus jamming at least one of the node unit initialization signals, CSm, at the master unit. If the master unit does not receive a valid node-initialization spread spectrum signal, CSm, or identification code from a node unit during the time slot, it may cease to transmit any signal in that time slot for a predetermined period of time, or it may transmit a “jammed signal alarm” code through the master-identification spread spectrum signal, CSn2. When a lack of response or a jammed signal alarm code from the master unit is encountered, the node units which tried to access the master unit instantaneously, of the plurality, N-K, of node units, may then initiate a node unit internal “wait” state, whose period may be derived from each node unit's identification code. After the wait state period, the plurality of node units which failed to access the master unit may attempt to access it again. Since wait states may be highly unique to each node unit, it is unlikely that the same plurality of node units will jam each other again.
    [68] 68. If all N time slots are being used for communication or initialization functions by N node units, then the master-initialization spread spectrum signal, CSn1, is not transmitted by the master unit, and no new node units of the plurality of X - N node units may access the master unit until a time slot opens up through one or more of the N node units abandoning communications with the master unit.
    [69] 69. As an alternative architecture to the present embodiment, the master unit may operate such that the Nth time slot may be held in reserve to transmit a “busy” alarm to the plurality of N-K node units having not established communications with the master unit such that it informs them that no further access is available at that master unit, thereby allowing only N−1 node units to access the master unit.
    [70] 70.FIGS. 2A and 2B illustrate the foregoing protocol of the present invention.
    [71] 71.FIG. 2A illustrates the case where the node unit responds to the master-initialization signal with the node-initialization signal, which may be a simple acknowledgment (“ack”), to advise the master unit of the (K+1)th node unit's presence and desire to establish communications. The master and node units then proceed to exchange identification and communication signals as detailed above.
    [72] 72.FIG. 2B illustrates the case where the node unit responds to the master-initialization signal with the node-identification signal, decreasing the time and steps necessary to establish communications between the master unit and the (K+1)th node unit. The master and node units then proceed to exchange identification and communication signals as detailed above.
    [73] 73. The time division multiple access frame and time slots of the present invention are illustratively shown in FIG. 3. There are N time slots, with N=5, available for N node units to communicate with the master unit, with K=3 time slots already being used by the first K node units which are communicating with the master unit. During any one or all of the available N-K=4 time slots, the master unit transmits a master-initialization spread spectrum signal, CSn1, common to the set of X node units that may access the master unit, of which the N=5 node units is a subset. Since all node units which may access the master unit recognize the first master-initialization spread spectrum signal, CSn1, the 4th node unit trying to access the master unit will know that this time slot is available for communicating. In response to receiving the master-initialization spread spectrum signal, CSn1, in the 4th time slot, the 4th node unit may transmit in the 4th time slot to the master unit its identification code or a simple acknowledgment (“ACK”) through a first node-initialization spread spectrum signal, CSm1, common to all master units it may access, but distinct from the master-initialization spread spectrum signal, CSn1.
    [74] 74. In response to receiving the first node-initialization spread spectrum signal, CSm1, in the 4th time slot from the 4th node unit, the master unit transmits its 4th master-identification code, which may be distinct from all other master and node unit identification codes, with a master-identification spread spectrum signal, CSn2, common to the plurality of node units that may access the master unit and distinct from the master-initialization spread spectrum signal, CSn1, and the first node-initialization spread spectrum signal, CSm1. In response to receiving the 4th master-identification spread spectrum signal, CSn2, the 4th node unit may transmit in the 4th time slot its identification code through the second node-initialization spread spectrum signal, CSm2. In response to receiving the 4th node-identification code, the master unit derives a master unit spectrum spreading communication code for the 4th slot from the 4th node-identification code, and uses it to generate a master unit 4th slot communication spread spectrum signal, CMN4. The 4th master unit slot communication signal, CMN4, is then used for all transmissions from the master unit to the 4th node unit.
    [75] 75. If all node units utilize the same receive spread spectrum code (CMN4), the master unit does not necessarily have to derive a spectrum spreading code from the 4th node unit's identification code, but may rather, upon determination by the master unit that the 4th node unit's identification code is valid, transmit a spread spectrum communication signal common to all node units able to access the master and rely on address bits within the time slot to maintain synchronization of the four node units with the master unit.
    [76] 76. In response to receiving the master-identification code for the 4th time slot, the 4th node unit derives a 4th node unit spectrum spreading communication code from the master-identification code, and uses it to generate a 4th node unit communication spread spectrum signal, CNM4. The 4th node unit communication signal, CNM4, is then used for all transmissions from the 4th node unit to the master unit.
    [77] 77. In a particular embodiment, as illustrated in FIG. 4, there may be 4000 samples per second, divided into 1000 frames of four time slots of 250 microseconds each, allowing N=4 users to use one time slot 1000 times per second. The master unit transmits eighteen bits (two overhead/addressing, sixteen data) in each time slot it uses, yielding 16 kbps throughput from the master unit to each node unit per slot, which may be applied as compressed digital voice for a cordless telephone application. In initialization or identification modes, the eighteen bits may be used differently. Node units, which may be embodied as handsets as illustrated in FIG. 1, transmit eighteen bits per time slot only in response to receiving a spread spectrum initialization, identification, or communication signal from the master unit. The master unit transmission frame comprises four time slots, and is configured such that it does not transmit in a time slot except to send a spread spectrum communication signal to K users who are on line, plus an initialization (in the case of a search for a new node unit trying to access the master unit) or identification (in the case of a new node unit in the process of accessing a master unit) signal, leaving N-K-1 time slots open. If the master unit is transmitting a master-identification spread spectrum signal in the (K+1)th time slot (i.e. the (K+1)th node unit is accessing the system), it then may transmit a master-initialization spread spectrum signal in the (K+2)th time slot, in order to allow the (K+2)th node unit to access the master unit. Thus, if two node units are present, then the master unit transmits in the first through second time slots the communication spread spectrum signals pertaining to the first through second nodes, and in the third time slot an initialization spread spectrum signal common to all node units that may access the master unit, which may be distinct from all communication and identification spread spectrum signals.
    [78] 78. If, with N=4 and K=2 node units, a plurality of up to 2 node units try to access the master unit sequentially in time, with the period between access attempts being greater than or equal to the slot period, or 250 microseconds, upon reception of the master-initialization spread spectrum signal, CSn1, the third and fourth node units will access the third and fourth time slots, respectively, immediately available in the first time frame following their respective initiations of the access attempt. When the third node unit has accessed the system (master unit slot and third node unit identification signals are being transmitted in the third time slot), the master unit may wait to transmit the fourth master unit slot identification signal until the third slot is occupied with master unit-to-3rd node unit and/or third node unit-to-master unit communication signals. If, with N=4 and K=2 node units, a plurality of up to two node units tries to access the master unit instantaneously (the time period between node unit access attempts being less than the slot period, or 250 microseconds), upon reception of the master-initialization spread spectrum signal, CSn1, in the third time slot, the third and fourth node units will transmit a first node-initialization spread spectrum signal, CSm1, within the third time slot, thus jamming at least one of the first node-initialization signals, CSm1, at the master unit. If the master unit does not receive a valid initialization signal, CSm, or identification code from a node unit during the third slot, it may cease to transmit any signal in the third time slot for a predetermined period of time, or it may transmit a “jammed signal alarm” code through the master-identification spread spectrum signal, CSn2. When a lack of response or a jammed signal alarm code from the master unit is encountered, the third and fourth node units may then initiate a node unit internal “wait” state, whose period may be derived from each node unit's identification code. After the wait state period, the third and fourth node units may attempt to access it again. Since wait states may be highly unique to each node unit, it is unlikely that the third and fourth node will units jam each other again. If all four time slots are being used for communication or initialization functions by four node units, then the initialization spread spectrum signal, CSn1, is not transmitted by the master unit, and no new node units of the plurality of X−4 node units may access the master unit.
    [79] 79. With N=4 and K=2, the master unit may function with the initialization, identification, and communication procedures detailed above, but may be configured to transmit the master-initialization spread spectrum signal, CSn1, in the vacant the third and fourth time slots. If the master unit does transmit the third and fourth vacant time slots, node units three and four may access the master unit in the third and fourth time slots, respectively or randomly. Therefore, the third node unit trying to access the master unit would access the first time slot immediately available after its initiation of the access attempt, instead of waiting for the third time slot to occur in the next frame.
    [80] 80. Thus, if two users are present, the master unit transmits in the first through second time slots the master unit communication spread spectrum signals, CMN1 through CMN2, pertaining to the first through second node units, and in the third through fourth time slots a master initialization spread spectrum signal, CSn1, common to the plurality, X, of node units that may access the master unit, which may be distinct from all master or node unit communication and identification spread spectrum signals. If two node units try to access the master unit sequentially in time, with the period between access attempts being greater than or equal to the slot period of 250 microseconds, upon reception of the master-initialization spread spectrum signal, CSn1, each node unit will access the open time slot available immediately following its initiation of the access attempt. When the third node unit has accessed the master unit (master unit slot and third node unit identification signals are being transmitted in the third time slot), the master unit may wait to transmit the fourth master unit slot identification signal until the third slot is occupied with master unit-to-4th node unit and/or third node unit-to-master unit communication signals.
    [81] 81. If a plurality of up to two node units tries to access the master unit instantaneously (the time period between node unit access attempts being less than the slot period, or 250 microseconds), upon reception of the master-initialization spread spectrum signal, CSn1, the third and fourth node units will transmit a first node-initialization spread spectrum signal, CSM1, or second node-initialization spread spectrum signal, CSm2, within the same time slot, thus jamming at least one of the node-initialization spread spectrum signal or node-identification spread spectrum signal, CSm, at the master unit. If the master unit does not receive a valid node-initialization spread spectrum signal or node-identification spread spectrum signal, CSm1, or identification code from a node unit during the time slot, it may cease to transmit any signal in that time slot for a predetermined period of time, or it may transmit a “jammed signal alarm” code through the master-identification spread spectrum signal, CSn2. When a lack of response or a jammed signal alarm code from the master unit is encountered, the third and fourth node units may initiate a node unit internal “wait” state, whose period may be derived from each node unit's identification code. After the wait state period, the third and fourth node units may attempt to access it again. Since wait states may be highly unique to each node unit, it is unlikely that the third and fourth node units will jam each other again.
    [82] 82. The timing structure illustrated in FIG. 4 for the communication mode serves as example only, and is not intended to be restrictive in or to the current embodiment of the invention. The number of address, overhead, and data bits, turnaround, delay, and transmitter turn-on/off times, bit periods, samples, frames and/or slots per second may be different according to the operational mode the system is in (i.e. initialization, identification, communication) as well as the specific implementation of the invention.
    [83] 83. In another embodiment, as illustrated in FIG. 5, the system operates as in the first embodiment (i.e. node units transmit only in response to a master unit transmission of the node unit's code, the K and N-K slots operating the same, etc.) except that the master and node transmit M-ary data bits per code sequence. In this embodiment, there may be 25000 samples per second, divided into 1000 frames per second of 25 time slots of 40 microseconds each, allowing N=25 users to use one time slot 1000 times per second. (See FIG. 5.) The master unit transmits 22 binary data bits (6 overhead/addressing, 16 data) in quarternary operation, where each code sequence transmission represents two binary data bits, or four binary states, which may be represented as: Code Sequence Number Data Bits 0 00 1 01 2 10 3 11
    [84] 84. The master-node link therefore yields 16 kbps throughput per slot. In initialization or identification nodes, the data structure of the transmission may be different in order for the handshaking operations to be completed. Node units, which may be embodied as handsets illustrated in FIG. 1, transmit 22 binary data bits in each time slot (6 overhead/addressing, 16 data) in 16-ary operation, wherein each code sequence transmission represents four binary data bits, or sixteen binary states, which may be represented as: Code Sequence Number Data Bits0 0000 1 0001 2 0010 3 0011 4 0100 5 0101 6 0110 7 0111 8 1000 9 1001 10 1010 11 1011 12 1100 13 1101 14 1110 15 1111
    [85] 85. The node-master unit link therefore yields 16 kbps throughput per slot. In initialization or identification nodes, the data structure of the transmission may be different in order for the handshaking operations to be completed.
    [86] 86. The timing structure illustrated in FIG. 5 for the communication mode serves as example only, and is not intended to be restrictive in or the current embodiment of the invention. The number of address, overhead, and data bits, turnaround, delay, and transmitter turn-on/off times, bit period, m-ary operations, samples, frames and/or slots per second may be different according to the operational mode the system is in (i.e. initialization, identification, communication) as well as the specific implementation of the invention.
    [87] 87. There are obvious advantages to the M-ary approach. One is more node units per master unit for the same bandwidth. Another is lower receiver complexity in the node units, which allows for a more practical implementation in handheld, battery powered devices such as telephones. For example, in the current embodiment, the node receiver could store fewer spread spectrum codes, reducing its complexity, relying on the master unit to contain more spread spectrum codes and complexity.
    [88] 88. The present invention allows for multiple base stations to be situated closely together through the use of frequency offsets in a three frequency zone architecture, as illustrated in FIG. 6. By relying on code division multiplexing, frequency re-use can be employed in every other zone. This requires that node units be able to scan the three frequencies to determine which is used by the master unit whose zone the node is in.
    [89] 89. In a second embodiment of the present invention, a fixed, or Fth, time slot, such as the 1st or Nth slots of the plurality of N time slots in a time frame, serves as the access slot. The second method and apparatus comprises the steps of transmitting in the Fth time slot from the master unit the master-initialization spread spectrum signal, CSn1, common to all node units. The Fth time slot may occupy a fixed time slot within the time frame of the N-K unused time slots, and does not change slots as the number, K, of node units which have established communications links with the master unit, changes.
    [90] 90. In response to receiving the master-initialization spread spectrum signal, CSn1, in the Fth time slot, the (K+1)th node unit transmits in the Fth time slot a (K+1)th node-initialization spread spectrum signal, CSm, which may be the same as CSn1, common to all master units that the (K+1)th node unit may access, which may contain the (K+1)th node unit's identification code.
    [91] 91. The master unit receives the node-initialization spread spectrum signal, CSm, in the Fth time slot from the (K+1)th node unit, and transmits in the Fth time slot a master-identification spread spectrum signal, CSn2, which may be distinct from spread spectrum signal CSn1 but common to all X node units, containing the master unit's (K+1)th slot identification code, which may include information directing the (K+1)th node unit as to which time slot and spectrum spreading code to use for communication from the (K+1)th node unit to the master unit.
    [92] 92. In response to receiving the master-identification spread spectrum signal, CSn2, the (K+1)th node unit may transmit in the Fth time slot the (K+1)th node-initialization spread spectrum signal, CSm, common to all master units that it may access, which may contain its (K+1)th node unit identification code, which may have a high degree of uniqueness to the plurality of the N−1 other node units.
    [93] 93. The master unit receives the (K+1)th node unit's identification code from the (K+1)th node unit in the Fth time slot via the node-initialization spread spectrum signal, CSm, common to all master units accessible by the (K+1)th node unit, and transmits in the (K+1)th time slot a master unit (K+1)th slot communication spread spectrum signal, CMNk+1, generated from a spectrum spreading code derived from the (K+1)th node unit's identification code.
    [94] 94. In response to receiving the (K+1)th master unit identification code from the master unit in the Fth time slot via the master-identification spread spectrum signal, CSn2, common to all X node units, the (K+1)th node unit transmits in the (K+1)th time slot a (K+1)th node unit communication spread spectrum signal, CNMk+1, generated from a spectrum spreading code derived from the (K+1)th master-identification code.
    [95] 95. As an alternative architecture of the second embodiment, the (K+1)th node unit may transmit the (K+1)th node communication spread spectrum signal in the (K+1)th time in slot in response to receiving the master unit (K+1)th slot communication signal in the (K+1)th time slot. In this case, the master-identification spread spectrum signal transmitted in the Fth time slot would not necessarily contain information detailing which time slot of the N-K time slots to use for communication transmissions.
    [96] 96. In the second embodiment, the master unit may operate such that it does not transmit in a time slot except to send a plurality of K master unit slot communication spread spectrum signals, CMN1 to CMNK, to K node units which have established communications links with the master unit, plus a master-initialization spread spectrum signal, CSn1, in the case of a search for a new node unit trying to access the master unit, or a master-identification spread spectrum signal, CSn2, in the case of a node unit being in the process of accessing a master unit, in the Fth time slot, leaving N-K-1 time slots unused. If the master unit is transmitting a master-identification spread spectrum signal, CSn2, in the Fth time slot (assuming the (K+1)th node unit is in the process of accessing the system), it then may transmit a master initialization spread spectrum signal, CSn1, in one of the N-K-1 unused time slots, in order to allow the (K+2)th node unit to access the master unit.
    [97] 97. If a plurality of up to N-K node units tries to access the master unit sequentially in time, with the period between access attempts being greater than or equal to the frame period, upon reception of the master-initialization spread spectrum signal, CSn1, each node unit of the plurality of N-K node units will access the (K+1)th time slot through the Fth time slot immediately available following its initiation of the access attempt. When the first (K+1)th node unit has accessed the system (assuming the master-identification and (K+1)th node-identification spread spectrum signals are being transmitted in the Fth time slot), the master unit may wait to transmit the (K+2)th master-identification spread spectrum signal until the (K+1)th slot is occupied with master unit-to-(K+1)th node unit and/or (K+1)th node unit-to-master unit communication signals.
    [98] 98. If a plurality of up to N-K node units tries to access the master unit instantaneously (the time period between node unit access attempts being less than the frame period), upon reception of the master-initialization spread spectrum signal, CSn1, in the Fth time slot, each node unit of this plurality of anode units will transmit a node-initialization spread spectrum signal, CSm, within the same time slot, thus jamming at least one of the node-initialization spread spectrum signals, CSm, at the master unit. If the master unit does not receive a valid initialization signal, CSm, or identification code from a node unit during the time slot, it may cease to transmit any signal in the Fth time slot for a predetermined period of time, or it may transmit a “jammed signal alarm” code through the master-identification spread spectrum signal, CSn2. When a lack of response or a jammed signal alarm code from the master unit is encountered, the node units which tried to access the master unit instantaneously, of the plurality, N-K, of node units, may then initiate a node unit internal “wait” state, whose period may be derived from each node unit's identification code. After the wait state period, the plurality of node units which failed to access the master unit may attempt to access it again. Since wait states may be highly unique to each node unit, it is unlikely that the same plurality of node units will jam each other again.
    [99] 99. If all N−1 time slots are being used for communication or initialization functions by N−1 node units, then the master-initialization spread spectrum signal, CSn1, is not transmitted. The master unit may operate such that the Fth time slot may a “busy” alarm to the plurality of N-K node units having not established communications with the master unit such that it informs them that no further access is available at that master unit, thereby allowing only N−1 node units to access the master unit.
    [100] 100. In a third embodiment of the present invention, the master unit may function with the initialization, identification, and communication protocols as set forth in the first and second embodiments, but may be configured to transmit the master-initialization spread spectrum signal, CSn1, in a plurality of vacant (N-K) time slots, simultaneously. If the master unit does transmit in a plurality of vacant (N-K) time slots, node units (K+1), (K+2), (K+3), . . . , (K+(N-K) (or N) may access the master unit in the (K+1)th, (K+2)th, (K+3)th, . . . , (K+(N-K))th (or Nth) time slots, respectively or randomly. Therefore, the (K+1)th node unit trying to access the master unit would access the first time slot immediately available after its initiation of the access attempt, instead of waiting for the (K+1)th or Fth time slot to occur in the next frame.
    [101] 101. Thus, if K users are present, the master unit transmits in the 1st through Kth time slots the master unit communication spread spectrum signals, CMN1 through CMNk, pertaining to the 1st through Kth node units, and in the (K+1)th through Nth time slots a master initialization spread spectrum signal, CSn1, common to the plurality, X, of node units that may access the master unit, which may be distinct from all master or node unit communication and identification spread spectrum signals.
    [102] 102. If a plurality of up to N-K node units tries to access the master unit sequentially in time, with the period between access attempts being greater than or equal to the slot period, upon reception of the master-initialization spread spectrum signal, CSn1, each node unit will access the open time slot available immediately following its initiation of the access attempt. When the first (K+1)th node unit has accessed the master unit (master unit slot and (K+1)th node unit identification signals are being transmitted in the (K+1)th time slot), the master unit may wait to transmit the (K+2)th through Nth master unit slot identification signals until the (K+1)th slot is occupied with master unit-to-(K+1)th node unit and/or (K+1)th node unit-to-master unit communication signals.
    [103] 103. If a plurality of up to N-K node units tries to access the master unit instantaneously (the time period between node unit access attempts being less than the slot period), upon reception of the master-initialization spread spectrum signal, CSn1, each node unit of this plurality of node units will transmit a node-initialization spread spectrum signal, CSm, within the same time slot, thus jamming at least one of the node-initialization spread spectrum signals, CSm, at the master unit. If the master unit does not receive a valid node-initialization spread spectrum signal, CSm, or identification code from a node unit during the time slot, it may cease to transmit any signal in that time slot for a predetermined period of time, or it may transmit a “jammed signal alarm” code through the master unit slot identification signal, CSn2. When a lack of response or a jammed signal alarm code from the master unit is encountered, the node units which tried to access the master unit Instantaneously, of the plurality, N - K, of node units, may initiate a node unit internal “wait” state, whose period may be derived from each node unit's identification code. After the wait state period, the plurality of node units which failed to access the master unit may attempt to access it again. Since wait states may be highly unique to each node unit, it is unlikely that the same plurality of node units will jam each other again.
    [104] 104. If all N time slots are being used for communication or initialization functions by N node units, then the initialization spread spectrum signal, CSn1, is not transmitted by the master unit, and no new node units of the plurality of X - N node units may access the master unit. The master unit may operate such that the Nth time slot may transmit a “busy” alarm to the plurality of N-K node units having not established communications with the master unit such that it informs them that no further access is available at that master unit, thereby allowing only N−1 node units to access the master unit.
    [105] 105. It will be apparent to those skilled in the art that various modifications can be made to the method for establishing spread spectrum communications between a master unit and a plurality of node units of the present invention, without departing from the scope or spirit of the invention, and it is intended that the present invention cover modifications and variations of the method for establishing spread spectrum communications as described herein, provided they come within the scope of the appended claims and their equivalents.
    权利要求:
    Claims (12)
    [1" id="US-20010000136-A1-CLM-00001] 1. A method for establishing communications between a unit and a plurality of N node units wherein K node units of said plurality of node units have established communications channels with said master unit using upto 2K different spread spectrum codes, respectively, with a time slot for each the the K node units in the first K time slots, respectively, and a first node unit of the N-K node units of said plurality of said node units, desires to establish communications with said master unit, comprising the steps of:
    transmitting, in a (K+1)th time slot from said master unit, a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    transmitting, in the (K+1)th time slot from said first node unit, responsive to receiving the master-initialization spread spectrum signal at said first node unit, a first node-initialization spread spectrum signal;
    transmitting, in the (K+1)th time slot from said master unit, responsive to receiving the first node-initialization spread spectrum signal at said master unit, a master-identification spread spectrum signal with a master-unit-slot-identification code, modulated by the master-common-signalling chip code having a master-identification code;
    transmitting, in the (K+1)th time slot from said first node unit, responsive to receiving the master-identification spread spectrum signal at said first node unit, a second node-initialization spread spectrum signal modulated by a (K+1)-node-identification code and the master-common-signalling chip code;
    generating, at said first node unit using the master identification code, a master unit chip code for transmitting spread spectrum signals to said master unit;
    generating, at said master unit using the (K+1)-node-identification code, a (K+1)-node-unit chip code for transmitting: spread spectrum signals to said first node unit; and
    communicating from said master unit using the (K+1)-node-unit chip code to said first node unit, and from said first node unit using the master unit chip code to said master unit, in the (K+1)th time slot.
    [2" id="US-20010000136-A1-CLM-00002] 2. A method for establishing communications between a master unit and a first node unit comprising the steps of:
    transmitting, a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    transmitting, responsive to receiving the master-initialization spread spectrum signal at said first node unit, a first node-initialization spread spectrum signal;
    transmitting, responsive to receiving the first node-initialization spread spectrum signal at said master unit, a master-identification spread spectrum signal having a master-unit-slot-identification code modulated by the master-common-signalling chip code having a master-identification code;
    transmitting, responsive to receiving the master-identification spread spectrum signal at said first node unit, a second node-initialization spread spectrum signal modulated by a first identification code and the master-common-signalling chip code of the master-initialization spread spectrum signal;
    generating, at said first-node unit using the master identification spread spectrum signal, a master unit chip code for transmitting spread spectrum signals to said master unit.
    [3" id="US-20010000136-A1-CLM-00003] 3. The method as set forth in
    claim 2 further comprising the steps, using a second node unit, of:
    transmitting, responsive to receiving the master-initialization spread spectrum signal at said second node unit, a third node-initialization spread spectrum signal;
    transmitting, responsive to receiving the second node-initialization spread spectrum signal at said master unit, a master-identification spread spectrum signal having the master-unit slot-identification code;
    transmitting, responsive to receiving the master-identification spread spectrum signal at said second node unit, a fourth node-initialization spread spectrum signal modulated by a (K+2)-node-identification code and the master-common-signalling chip code;
    generating, at said second node unit using the master-identification code, a second master unit chip code for transmitting spread spectrum signals to said master unit; and
    generating, at said master unit using the (K+2)-node-identification code, a (K+2)-node-unit chip code for transmitting spread spectrum signals to said second node unit.
    [4" id="US-20010000136-A1-CLM-00004] 4. A system for establishing communications between a master unit and a plurality of N node units wherein K node units of said plurality of node units have established communications channels with said master unit using upto 2K different spread spectrum codes, respectively, with a time slot for each the the K node units in the first K time slots, respectively, and a first node unit of the N-K node units of said plurality of said node units, desires to establish communications with said master unit, comprising:
    means, located at said master unit, for transmitting, in a (K+1)th time slot from said master unit, a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    means, located at said first node unit and responsive to receiving the master-initialization spread spectrum signal at said first node unit, for transmitting, in the (K+1)th time slot from said first node unit, a first node-initialization spread spectrum signal;
    means, located at said master unit and responsive to receiving the first node-initialization spread spectrum signal at said master unit, for transmitting in the (K+1)th time slot from said master unit, a master-identification spread spectrum signal with a master-unit-slot-identification code, modulated by the master-common-signalling chip code having a master-identification code;
    means located at said first node unit and responsive to receiving the master-identification spread spectrum signal at said first node unit, for transmitting, in the (K+1)th time slot from said first node unit, a second node-initialization spread spectrum signal modulated by a (K+1)-node-identification code and the master-common-signalling chip code;
    means, located at said first node unit and using the master identification code, for generating a master unit chip code for transmitting spread spectrum signals to said master unit;
    mean, located at said master unit and using the (K+1)-node-identification code, for generating a (K+1)-node-chip code for transmitting spread spectrum signals to said first node unit;
    means located at said master unit for communicating from said master unit using the (K+1)-node-unit chip code, in the (K+1)th time slot; and
    means located at said first node unit for communicating from said first node unit using the master unit chip code, in the (K+1)th time slot.
    [5" id="US-20010000136-A1-CLM-00005] 5. A system for establishing communications between a master unit and a first node unit, comprising:
    means, located at said master unit, for transmitting a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    means, located at said first node unit and responsive to receiving the master-initialization spread spectrum signal, for transmitting a first node-initialization spread spectrum signal;
    means, located at said master unit and responsive to receiving the first node-initialization spread spectrum signal, for transmitting a master-identification spread spectrum signal with a master-unit-slot-identification code, modulated by the master-common-signalling chip code having a master-identification code;
    means located at said first node unit and responsive to receiving the master-identification spread spectrum signal, for transmitting a second node-initialization spread spectrum signal modulated by a (K+1)-node-identification code and the master-common-signalling chip code;
    means, located at said first node unit and using the master identification code, for generating a master unit chip code for transmitting spread spectrum signals to said master unit;
    mean, located at said master unit and using the first identification code, for generating a (K+1)-node-unit chip code for transmitting spread spectrum signals to said first node unit;
    means located at said master unit for communicating from said master unit using the (K+1)-node-unit chip code, in the (K+1)th time slot; and
    means located at said first node unit for communicating from said first node unit using the master unit chip code, in the (K+1)th time slot.
    [6" id="US-20010000136-A1-CLM-00006] 6. The system as set forth in
    claim 5 using a second node unit comprising:
    means located at said second node unit and responsive to receiving the master-initialization spread spectrum signal at said second node unit, for transmitting a third node-initialization spread spectrum signal;
    means located at said master unit and responsive to receiving the third node-initialization spread spectrum signal, for transmitting a master-identification spread spectrum signal having the master-slot-identification code modulated by the master-common-signalling chip code having a master-identification code;
    means located at said second node unit and responsive to receiving the master-identification spread spectrum signal, for transmitting a fourth node-initialization spread spectrum signal modulated by a (K+2)-node-identification code and the master-common-signalling chip code;
    means located at said second node unit using the master-identification code, for generating a second master unit chip code for transmitting spread spectrum signals to said master unit; and
    means located at said master unit using the second identification code, for generating a (K+2)-node-unit chip code for transmitting spread spectrum signals to said second node unit.
    [7" id="US-20010000136-A1-CLM-00007] 7. A method for establishing communications between a master unit and a plurality of N node units wherein K node units of said plurality of node units have established communications channels with said master unit using upto 2K different spread spectrum codes, respectively, with a time slot for each the the K node units in the first K time slots, respectively, and a first node unit of the N-K node units of said plurality of said node units, desires to establish communications with said master unit, comprising the steps of:
    transmitting, in a (K+1)th time slot from said master unit, a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    transmitting, in the (K+1)th time slot from said first node unit, responsive to receiving the master-initialization spread spectrum signal at said first node unit, a node-identification spread spectrum signal modulated by a (K+1)-node-identification code and the node-common-signalling chip code;
    transmitting, in the (K+1)th time slot from said master unit, responsive to receiving the first node-initialization spread spectrum signal at said master unit, a master-identification spread spectrum signal with a master-unit-slot-identification code, modulated by the master-common-signalling chip code having a master-identification code;
    generating, at said first node unit using the master identification code, a master unit chip code for transmitting spread spectrum signals to said master unit;
    generating, at said master unit using the (K+1)-node-identification code, a (K+1)-node-unit chip code for transmitting spread spectrum signals to said first node unit; and
    communicating from said master unit using the (K+1)-node-unit chip code, and from said first node unit using the master unit chip code, in the (K+1)th time slot.
    [8" id="US-20010000136-A1-CLM-00008] 8. A method for establishing communications between a master unit and a first node unit comprising the steps of:
    transmitting from said master unit a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    transmitting, responsive to receiving the master-initialization spread spectrum signal at said first node unit, a first node-identification spread spectrum signal modulated by a first identification code;
    transmitting, responsive to receiving the first node-identification spread spectrum signal at said master unit, a master-identification spread spectrum signal having a master-unit-slot-identification code;
    generating, at said first node unit using the master identification code, a master unit chip code for transmitting spread spectrum signals to said master unit;
    generating, at said master unit using the (K+1)-node-identification code, a (K+1)-node-unit chip code for transmitting spread spectrum signals to said first node unit; and
    communicating from said master unit using the (K+1)-node-unit chip code, and from said first node unit using the master unit chip code.
    [9" id="US-20010000136-A1-CLM-00009] 9. The method as set forth in
    claim 8 further comprising the steps, using a second node unit, of:
    transmitting, responsive to receiving the master-initialization spread spectrum signal at said second node unit, a second node-unit-identification spread spectrum signal modulated by a second identification code;
    transmitting, responsive to receiving the second node-unit-identification spread spectrum signal at said master unit, a master-identification spread spectrum signal having the master-unit-identification code;
    generating, at said second node unit using the master-identification code, a second master unit chip code for transmitting spread spectrum signals to said master unit; and
    generating, at said master unit using the (K+1)-node-identification code, a (K+2)-node-unit chip code for transmitting spread spectrum signals to said second node unit.
    [10" id="US-20010000136-A1-CLM-00010] 10. A system for establishing communications between a master unit and a plurality of N node units wherein K node units of said plurality of node units have established communications channels with said master unit using upto 2K different spread spectrum codes, respectively, with a time slot for each the the K node units in the first K time slots, respectively, and a first node unit of the N-K node units of said plurality of said node units, desires to establish communications with said master unit, comprising:
    means, located at said master unit, for transmitting, in a (K+1)th time slot from said master unit, a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    means, located at said first node unit and responsive to receiving the master-identification spread spectrum signal at said first node unit, for transmitting, in the (K+1)th time slot from said first node unit, a node-identification spread spectrum signal modulated by a first identification code and the master-common-signalling chip code of the master-initialization spread spectrum signal;
    means, located at said master unit and responsive to receiving the first node-identification spread spectrum signal at said master unit, for transmitting in the (K+1)th time slot from said master unit, a master-identification spread spectrum signal with a master-unit-slot-identification code, modulated by the master-common-signalling chip code having a master-identification code;
    means, located at said first node unit and using the master identification code, for generating a master unit chip code for transmitting spread spectrum signals to said master unit;
    mean, located at said master unit and using the (K+1)-node-identification code, for generating a (K+1)-node-chip code for transmitting spread spectrum signals to said first node unit;
    means located at said master unit for communicating from said master unit using the (K+1)-node-unit chip code, in the (K+1)th time slot; and
    means located at said first node unit for communicating from said first node unit using the master unit chip code, in the (K+1)th time slot.
    [11" id="US-20010000136-A1-CLM-00011] 11. A system for establishing communications between a master unit and a first node unit, comprising:
    means, located at said master unit, for transmitting a master-initialization spread spectrum signal modulated by a master-common-signalling chip code;
    means, located at said first node unit and responsive to receiving the master-initialization spread spectrum signal, for transmitting, a first node-identification spread spectrum signal modulated by a first identification code;
    means, located at said master unit and responsive to receiving the first node-identification spread spectrum signal, for transmitting a master-identification spread spectrum signal with a master-unit-slot-identification code;
    means, located at said first node unit and using the master-identification code for generating a master unit chip code for transmitting spread spectrum signals to said master unit;
    mean, located at said master unit and using the first identification code, for generating a (K+1)-node-unit chip code for transmitting spread spectrum signals to said first node unit;
    means located at said master unit for communicating from said master unit using the (K+1)-node-unit chip code, in the (K+1)th time slot; and
    means located at said first node unit for communicating from said first node unit using the master unit chip code, in the (K+1)th time slot.
    [12" id="US-20010000136-A1-CLM-00012] 12. The system as set forth in
    claim 11 using a second node unit further comprising:
    means located at said second node unit and responsive to receiving the master-initialization spread spectrum signal at said second node unit, for transmitting a second node-identification spread spectrum signal modulated by a second identification code;
    means located at said master unit and responsive to receiving the second node-identification spread spectrum signal, the master-identification spread spectrum signal having the master-unit-identification code;
    means located at said second node unit using the master-identification code, for generating a second master unit chip code for transmitting spread spectrum signals to said master unit; and
    means located at said master unit using the (K+1)-node-identification code, for generating a (K+2)-node-unit chip code for transmitting spread spectrum signals to said second node unit.
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    同族专利:
    公开号 | 公开日
    AU8959191A|1992-05-20|
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    CA2094710C|1998-12-01|
    CA2094710A1|1992-04-24|
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4247942A|1961-03-01|1981-01-27|Ford Aerospace & Communications Corp.|Jam resistant communication system|
    US3634627A|1969-07-23|1972-01-11|Sits Soc It Telecom Siemens|Channel-allocation system for a channel-addressing multiple-access telecommunication system|
    USRE27738E|1971-12-22|1973-08-21||Takamichi honma |
    US3934203A|1974-05-24|1976-01-20|The United States Of America As Represented By The Secretary Of The Navy|Spread spectrum modem|
    US4653069A|1975-11-06|1987-03-24|General Electric Company|Spread spectrum correlation receiver|
    US3978436A|1975-11-10|1976-08-31|Rca Corporation|Surface acoustic wave device and method of making same|
    US4217563A|1975-12-22|1980-08-12|Westinghouse Electric Corp.|Surface wave phase correlator and monopulse radar system employing the same|
    US4090036A|1976-02-09|1978-05-16|Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence|Satellite communications system|
    US4021898A|1976-05-20|1977-05-10|Timex Corporation|Method of adjusting the frequency of vibration of piezoelectric resonators|
    US4163944A|1976-12-22|1979-08-07|Ncr Corporation|Compensation circuit for an electrical signal mixer|
    US4100498A|1977-06-20|1978-07-11|The United States Of America As Represented By The Secretary Of The Navy|Discrete chirp frequency synthesizer|
    US4314393A|1979-04-02|1982-02-09|Fujitsu Limited|Method of manufacturing acoustic surface wave device|
    US4445256A|1979-07-05|1984-05-01|Dryan-Fordahl Technologies S.A.|Method of manufacturing piezoelectric resonator components|
    US4455651A|1980-10-20|1984-06-19|Equatorial Communications Company|Satellite communications system and apparatus|
    US4525835A|1981-10-13|1985-06-25|International Standard Electric Corporation|Duplex radio system utilizing time compression expansion|
    US4432089A|1981-12-24|1984-02-14|Motorola, Inc.|Digital loop transceiver for interfacing a digital PABX to a digital subscriber set via a subscriber line|
    US4517679A|1982-03-10|1985-05-14|Emi Limited|Communication over noisy lines|
    US4456793A|1982-06-09|1984-06-26|Bell Telephone Laboratories, Incorporated|Cordless telephone system|
    US4574378A|1982-06-14|1986-03-04|Nec Corporation|Multiple access system and method|
    US4563774A|1982-10-25|1986-01-07|At&T Bell Laboratories|Address coded communication system|
    US4587662A|1983-01-28|1986-05-06|International Standard Electric Corporation|TDMA spread-spectrum receiver with coherent detection|
    US4606039A|1983-07-21|1986-08-12|Societe Nationale D'etudes Et De Construction De Moteurs D'aviation S.N.E.C.M.A.|Spread spectrum coding method and apparatus|
    US4649549A|1983-08-30|1987-03-10|Sophisticated Signals And Circuits|Apparatus for synchronizing linear PN sequences|
    US4665404A|1983-10-24|1987-05-12|Offshore Navigation, Inc.|High frequency spread spectrum positioning system and method therefor|
    US4680785A|1983-11-11|1987-07-14|Nippo Communication Industrial Co., Ltd.|Personal-signaling communication system|
    US4660164A|1983-12-05|1987-04-21|The United States Of America As Represented By The Secretary Of The Navy|Multiplexed digital correlator|
    US4642505A|1984-03-05|1987-02-10|Motorola, Inc.|Laser trimming monolithic crystal filters to frequency|
    US4567588A|1984-03-23|1986-01-28|Sangamo Weston, Inc.|Synchronization system for use in direct sequence spread spectrum signal receiver|
    US4601047A|1984-03-23|1986-07-15|Sangamo Weston, Inc.|Code division multiplexer using direct sequence spread spectrum signal processing|
    US4601059A|1984-04-02|1986-07-15|Gammenthaler Robert S|Communications control circuit with adaptive timing|
    US4569062A|1984-06-28|1986-02-04|Dellande Brian W|Interface circuit for interfacing between asynchronous data in start/stop format and synchronous data|
    US4745378A|1984-09-21|1988-05-17|Clarion Co., Ltd.|Surface acoustic wave device|
    US4813057A|1984-12-03|1989-03-14|Charles A. Phillips|Time domain radio transmission system|
    US4641317A|1984-12-03|1987-02-03|Charles A. Phillips|Spread spectrum radio transmission system|
    US4829554A|1985-01-31|1989-05-09|Harris Corporation|Cellular mobile telephone system and method|
    US5005183A|1985-02-04|1991-04-02|Mitel Telecom Limited|Wireless telephone system|
    US4583048A|1985-02-26|1986-04-15|Rca Corporation|MSK digital demodulator for burst communications|
    US5119375A|1985-03-20|1992-06-02|International Mobile Machines Corp.|Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels|
    US5022024A|1985-03-20|1991-06-04|International Mobile Machines Corporation|Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels|
    US5121391A|1985-03-20|1992-06-09|International Mobile Machines|Subscriber RF telephone system for providing multiple speech and/or data singals simultaneously over either a single or a plurality of RF channels|
    US5022024B1|1985-03-20|1999-06-22|Interdigital Tech Corp|Subscriber rf telephone system for providing multiple speech and/or data signals simultaneously over either a signal or a plurality of rf channels|
    US4675863A|1985-03-20|1987-06-23|International Mobile Machines Corp.|Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels|
    US4912705A|1985-03-20|1990-03-27|International Mobile Machines Corporation|Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels|
    US4688210A|1985-03-29|1987-08-18|U.S. Philips Corporation|Method of and arrangement for synchronizing the receiver arrangements in a digital multiplex transmission system|
    US5124698A|1985-04-10|1992-06-23|Tecnomen Oy|Method and apparatus for synchronizing radio transmitters in a paging network|
    US4742512A|1985-07-19|1988-05-03|Nec Corporation|Multipoint communication system having polling and reservation schemes|
    US4763322A|1985-07-31|1988-08-09|U.S. Philips Corp.|Digital radio transmission system with variable duration of the time slots in the time-division multiplex frame|
    US4754453A|1985-07-31|1988-06-28|U.S. Philips Corporation|Digital radio transmission system with a connection-accompanying organization channel in the time-division multiplex frame|
    US4918689A|1985-10-10|1990-04-17|Bell Communications Research, Inc.|Asynchronous communication system|
    US4672254A|1985-10-11|1987-06-09|Massachusetts Institute Of Technology|Surface acoustic wave devices and method of manufacture thereof|
    US4672658A|1985-10-16|1987-06-09|At&T Company And At&T Bell Laboratories|Spread spectrum wireless PBX|
    US4647863A|1985-11-01|1987-03-03|The United States Of America As Represented By The Secretary Of The Army|Saw transition detector for PSK signals|
    US4724435A|1985-11-06|1988-02-09|Applied Spectrum Technologies, Inc.|Bi-directional data telemetry system|
    US4718080A|1985-12-16|1988-01-05|Serrano Arthur L|Microprocessor controlled interface for cellular system|
    US4736371A|1985-12-30|1988-04-05|Nec Corporation|Satellite communications system with random multiple access and time slot reservation|
    US4765753A|1986-03-08|1988-08-23|U.S. Philips Corporation|Method and apparatus for handing-over a radio connection from one radio cell to another radio cell of a digital radio transmission system|
    US4745628A|1986-04-15|1988-05-17|Terra Marine Engineering, Inc.|Symbol generator for phase modulated system|
    US4815106A|1986-04-16|1989-03-21|Adaptive Networks, Inc.|Power line communication apparatus|
    US4837786A|1986-08-07|1989-06-06|Comstream Corporation|Technique for mitigating rain fading in a satellite communications system using quadrature phase shift keying|
    US4807222A|1986-08-25|1989-02-21|American Telephone And Telegraph Company At&T Bell Laboratories|Cordless accessed high-speed high-capacity local area networks|
    US4837802A|1986-09-18|1989-06-06|Sony Corporation|Radio communication method and system|
    US4754473A|1986-10-16|1988-06-28|Willie Edwards|Remote telephonic data transcribing system|
    US4901307A|1986-10-17|1990-02-13|Qualcomm, Inc.|Spread spectrum multiple access communication system using satellite or terrestrial repeaters|
    US4804938A|1986-10-24|1989-02-14|Sangamo Weston, Inc.|Distribution energy management system|
    US4759078A|1986-11-14|1988-07-19|Rose Communication Systems, Inc.|Coordinated local oscillator receiving system|
    US4759034A|1986-12-02|1988-07-19|General Research Of Electronics, Inc.|Multi-step spread spectrum communication apparatus|
    US4797947A|1987-05-01|1989-01-10|Motorola, Inc.|Microcellular communications system using macrodiversity|
    US4833702A|1987-05-13|1989-05-23|Nec Corporation|Telephone registration and cancellation control in a wide area cordless telephone system|
    US4893327A|1987-07-20|1990-01-09|Motorola, Inc.|Colocated cellular radiotelephone systems|
    US4905221A|1987-08-24|1990-02-27|Nec Corporation|Earth station capable of effectively using a frequency band of a satellite|
    US4894842A|1987-10-15|1990-01-16|The Charles Stark Draper Laboratory, Inc.|Precorrelation digital spread spectrum receiver|
    US4918690A|1987-11-10|1990-04-17|Echelon Systems Corp.|Network and intelligent cell for providing sensing, bidirectional communications and control|
    US4800885A|1987-12-02|1989-01-31|The Boc Group, Inc.|Blood constituent monitoring apparatus and methods with frequency division multiplexing|
    US5093637A|1987-12-27|1992-03-03|Mitsubishi Denki Kabushiki Kaisha|Modulation device with input signal modification for correction of amplifier nonlinearities|
    US4805208A|1988-01-15|1989-02-14|Niravoice, Inc.|Modem compression system for telephone network|
    US5111535A|1988-02-25|1992-05-05|Nec Corporation|Method and system for switching radio frequency|
    US4995083A|1988-09-02|1991-02-19|Gec Plessey Telecommunications Limited|Method of establishing a radio link in one of a plurality of channels between two radio units|
    US4984247A|1988-09-29|1991-01-08|Ascom Zelcom Ag|Digital radio transmission system for a cellular network, using the spread spectrum method|
    US5134710A|1988-10-17|1992-07-28|Telefonaktiebolaget L M Ericsson|Method of transmitting call information in a short range mobile telephone system and a radio unit for carrying out the method|
    US4916691A|1988-10-28|1990-04-10|American Telephone And Telegraph Company|Telecommunications switching system|
    US5416779A|1989-01-27|1995-05-16|British Telecommunications Public Limited Company|Time division duplex telecommunication system|
    US5023887A|1989-03-02|1991-06-11|Tokyo Keiki Company Ltd.|Data transmission system using spread spectrum communication|
    US4943973A|1989-03-31|1990-07-24|At&T Company|Spread-spectrum identification signal for communications system|
    US5022046A|1989-04-14|1991-06-04|The United States Of America As Represented By The Secretary Of The Air Force|Narrowband/wideband packet data communication system|
    US5200956A|1989-05-26|1993-04-06|U.S. Philips Corporation|Communications system for data transmission over a time division duplex frequency channel|
    US5008953A|1989-06-26|1991-04-16|Telefonaktiebolaget L M Ericsson|Mobile station link supervision utilizing digital voice color codes|
    US5016255A|1989-08-07|1991-05-14|Omnipoint Data Company, Incorporated|Asymmetric spread spectrum correlator|
    US5022047A|1989-08-07|1991-06-04|Omnipoint Data Corporation|Spread spectrum correlator|
    US5109390A|1989-11-07|1992-04-28|Qualcomm Incorporated|Diversity receiver in a cdma cellular telephone system|
    US5101501A|1989-11-07|1992-03-31|Qualcomm Incorporated|Method and system for providing a soft handoff in communications in a cdma cellular telephone system|
    US5191597A|1990-01-22|1993-03-02|Telefonaktiebolaget L M Ericsson|Method of compensating for non-linearities in an end amplifier incorporated in a radio transmitter|
    US5025452A|1990-03-20|1991-06-18|Andrew Corporation|Full-duplex, sub-band spread spectrum communications system|
    US5018165A|1990-03-21|1991-05-21|Andrew Corporation|Communication system using spread spectrum and leaky transmission line|
    US5103459B1|1990-06-25|1999-07-06|Qualcomm Inc|System and method for generating signal waveforms in a cdma cellular telephone system|
    US5103459A|1990-06-25|1992-04-07|Qualcomm Incorporated|System and method for generating signal waveforms in a cdma cellular telephone system|
    US5229995A|1990-07-17|1993-07-20|Northern Telecom Limited|Radio link architecture for wireless communication systems|
    US5299198A|1990-12-06|1994-03-29|Hughes Aircraft Company|Method and apparatus for exploitation of voice inactivity to increase the capacity of a time division multiple access radio communications system|
    US5303286A|1991-03-29|1994-04-12|Space Systems/Loral, Inc.|Wireless telephone/satellite roaming system|
    US5179571A|1991-07-10|1993-01-12|Scs Mobilecom, Inc.|Spread spectrum cellular handoff apparatus and method|
    US5400359A|1992-03-23|1995-03-21|Sharp Kabushiki Kaisha|Spread spectrum communication system and an apparatus for communication utilizing this system|
    US5420851A|1993-11-24|1995-05-30|At&T Corp.|Method of multiple access|US20050169349A1|1999-08-17|2005-08-04|Samsung Electronics Co., Ltd.|Method for communicating scrambling code ID in mobile communication system|
    US20080095174A1|2006-10-18|2008-04-24|Vladimir Oksman|Methods and systems for communication|
    US20090132674A1|2007-11-16|2009-05-21|Qualcomm Incorporated|Resolving node identifier confusion|
    US20090316655A1|2008-06-19|2009-12-24|Qualcomm Incorporated|Access terminal assisted node identifier confusion resolution|
    US20100040019A1|2008-07-15|2010-02-18|Qualcomm Incorporated|Wireless communication systems with femto nodes|
    US20100040038A1|2008-07-15|2010-02-18|Qualcomm Incorporated|Wireless communication systems with femto cells|
    US20150369535A1|2013-03-06|2015-12-24|Linde Aktiengesellschaft|Air separation plant, method for obtaining a product containing argon, and method for creating an air separation plant|
    US9648493B2|2007-11-16|2017-05-09|Qualcomm Incorporated|Using identifiers to establish communication|US27738A||1860-04-03||Railroad axle-box |
    FR2261653B1|1974-02-15|1978-01-06|Thomson Csf||
    US4112257A|1977-03-24|1978-09-05|Frost Edward G|Comprehensive automatic mobile radio telephone system|
    US4131484A|1978-02-13|1978-12-26|Western Electric Company, Inc.|Frequency adjusting a piezoelectric device by lasering|
    US4222115A|1978-03-13|1980-09-09|Purdue Research Foundation|Spread spectrum apparatus for cellular mobile communication systems|
    US4301530A|1978-12-18|1981-11-17|The United States Of America As Represented By The Secretary Of The Army|Orthogonal spread spectrum time division multiple accessing mobile subscriber access system|
    CH630747A5|1979-01-18|1982-06-30|Ebauches Sa|METHOD FOR ADJUSTING THE FREQUENCY OF A RESONATOR AND RESONATOR WITH ADJUSTED FREQUENCY OBTAINED BY THE IMPLEMENTATION OF THIS PROCESS.|
    US4355411A|1980-03-24|1982-10-19|Bell Telephone Laboratories, Incorporated|Technique for efficient spectrum utilization in mobile radio systems using space diversity|
    US4418393A|1980-10-27|1983-11-29|Sperry Corporation|Matched filter spread spectrum code recovery apparatus|
    US4418425A|1981-08-31|1983-11-29|Ibm Corporation|Encryption using destination addresses in a TDMA satellite communications network|
    US4484028A|1982-11-01|1984-11-20|Motorola, Inc.|Digital loop transceiver having a power up/down circuit|
    US4787093A|1983-03-21|1988-11-22|Develco, Inc.|Combinatorial coded telemetry|
    US4550414A|1983-04-12|1985-10-29|Charles Stark Draper Laboratory, Inc.|Spread spectrum adaptive code tracker|
    GB2144310A|1983-08-01|1985-02-27|Philips Electronic Associated|Multiple-access communications system|
    US4707839A|1983-09-26|1987-11-17|Harris Corporation|Spread spectrum correlator for recovering CCSK data from a PN spread MSK waveform|
    US4561089A|1984-03-23|1985-12-24|Sangamo Weston, Inc.|Correlation detectors for use in direct sequence spread spectrum signal receiver|
    DE3411014A1|1984-03-24|1985-09-26|Standard Elektrik Lorenz Ag, 7000 Stuttgart|MESSAGE TRANSFER SYSTEM|
    JPH0142174B2|1984-04-17|1989-09-11|Clarion Co Ltd||
    US4621365A|1984-11-16|1986-11-04|Hughes Aircraft Company|Synchronization preamble correlation detector and frequency estimator|
    US4622854A|1984-12-31|1986-11-18|Schlumberger Technology Corporation|Rounded wall surface acoustic wave sensors|
    CA1264844A|1985-06-05|1990-01-23|Nec Corporation|Time division switching system having a priorityselector responsive to proceed-to-send requests|
    US4701904A|1985-10-18|1987-10-20|American Telephone And Telegraph Company, At&T Bell Laboratories|Optical local area network employing microwave modulation techniques|
    US4703474A|1986-02-28|1987-10-27|American Telephone And Telegraph Company, At&T Bell Laboratories|Spread spectrum code-division-multiple-access lightwave communication system|
    EP0243900B1|1986-04-26|1993-07-21|Nec Corporation|Radio key telephone system having a common signaling channel|
    JPS6397033A|1986-10-14|1988-04-27|Kenwood Corp|Synchronizing pulse generation circuit for spread spectrum communication system|
    US4868811A|1987-03-10|1989-09-19|Kabushiki Kaisha Toshiba|Multiple access communication system|
    US4878238A|1987-12-23|1989-10-31|Rash Mark S|Cordless telephone network|
    CA1318368C|1988-01-14|1993-05-25|Yoshitaka Uchida|Correlation pulse generator|
    SE460749B|1988-03-15|1989-11-13|Ericsson Telefon Ab L M|PROCEDURE TO TRANSFER DATA INFORMATION IN A CELL-DIVIDED MOBILE RADIO COMMUNICATION SYSTEM|
    GB2232555A|1989-05-26|1990-12-12|Philips Electronic Associated|Digital cordless telephone systems|
    US5042082A|1989-06-26|1991-08-20|Telefonaktiebolaget L. M. Ericsson|Mobile assisted handoff|
    US4949395A|1989-07-07|1990-08-14|Telefonaktiebolaget L M Ericsson|Method and arrangement for dynamically allocating time slots to connections in a digital mobile radio system|
    US5056109A|1989-11-07|1991-10-08|Qualcomm, Inc.|Method and apparatus for controlling transmission power in a cdma cellular mobile telephone system|
    US5073900A|1990-03-19|1991-12-17|Mallinckrodt Albert J|Integrated cellular communications system|
    AU636736B2|1990-04-17|1993-05-06|Nec Corporation|Cordless key telephone system capable of quickly answering incoming calls|
    US5166929A|1990-06-18|1992-11-24|Northern Telecom Limited|Multiple access protocol|
    JP3093243B2|1990-07-12|2000-10-03|株式会社東芝|Mobile radio communication system|
    US5243641A|1990-08-01|1993-09-07|At&T Bell Laboratories|Extended range cordless telephone system|
    AU8959191A|1990-10-23|1992-05-20|Omnipoint Corporation|Method and apparatus for establishing spread spectrum communications|
    JP2723691B2|1991-04-30|1998-03-09|日本電気株式会社|Variable timing signal generation circuit|
    FI91345C|1992-06-24|1994-06-10|Nokia Mobile Phones Ltd|A method for enhancing handover|
    FI925472A|1992-12-01|1994-06-02|Nokia Mobile Phones Ltd|Data transfer procedure and system|
    US5404376A|1993-09-09|1995-04-04|Ericsson-Ge Mobile Communications Inc.|Navigation assistance for call handling in mobile telephone systems|
    US5446727A|1993-11-30|1995-08-29|Motorola Inc.|Method and apparatus for time aligning signals for reception in a code-division multiple access communication system|
    US5537397A|1994-06-07|1996-07-16|Aloha Networks, Inc.|Spread aloha CDMA data communications|
    US5614914A|1994-09-06|1997-03-25|Interdigital Technology Corporation|Wireless telephone distribution system with time and space diversity transmission for determining receiver location|
    US6085085A|1996-03-27|2000-07-04|Qualcomm Incorporated|Method and apparatus for performing preferred system selection|
    US5870674A|1996-03-27|1999-02-09|Qualcomm Incorporated|Method and apparatus for performing preferred system selection|
    US6073013A|1996-11-04|2000-06-06|Qualcomm Incorporated|Method and apparatus for performing position-based call processing in a mobile telephone system|
    US6208857B1|1996-11-04|2001-03-27|Qualcomm Incorporated|Method and apparatus for performing position-and preference-based service selection in a mobile telephone system|
    US5946618A|1996-11-04|1999-08-31|Qualcomm Incorporated|Method and apparatus for performing position-based call processing in a mobile telephone system using multiple location mapping schemes|AU8959191A|1990-10-23|1992-05-20|Omnipoint Corporation|Method and apparatus for establishing spread spectrum communications|
    US5402413A|1991-04-08|1995-03-28|Omnipoint Corporation|Three-cell wireless communication system|
    US5815525A|1991-05-13|1998-09-29|Omnipoint Corporation|Multi-band, multi-mode spread-spectrum communication system|
    US5887020A|1991-05-13|1999-03-23|Omnipoint Corporation|Multi-band, multi-mode spread-spectrum communication system|
    US5790587A|1991-05-13|1998-08-04|Omnipoint Corporation|Multi-band, multi-mode spread-spectrum communication system|
    US5694414A|1991-05-13|1997-12-02|Omnipoint Corporation|Multi-band, multi-mode spread-spectrum communication system|
    US5796772A|1991-05-13|1998-08-18|Omnipoint Corporation|Multi-band, multi-mode spread-spectrum communication system|
    US5285469A|1991-06-03|1994-02-08|Omnipoint Data Corporation|Spread spectrum wireless telephone system|
    EP0617864B1|1991-12-16|2002-02-27|XIRCOM Wireless, Inc.|Spread-spectrum data publishing system|
    GB2281470B|1993-04-02|1998-07-15|Motorola Ltd|Multichannel random access communications system|
    DE4319830A1|1993-06-16|1995-03-09|Philips Patentverwaltung|CDMA transmission system|
    US6005856A|1993-11-01|1999-12-21|Omnipoint Corporation|Communication protocol for spread spectrum wireless communication system|
    US6094575A|1993-11-01|2000-07-25|Omnipoint Corporation|Communication system and method|
    US6088590A|1993-11-01|2000-07-11|Omnipoint Corporation|Method and system for mobile controlled handoff and link maintenance in spread spectrum communication|
    US6092117A|1994-09-02|2000-07-18|Packard Bell Nec|System and method for automatically reconnecting a wireless interface device to a host computer|
    US6209034B1|1994-09-02|2001-03-27|Nec Corporation|Remote keyboard macros activated by hot icons|
    US6262719B1|1994-09-02|2001-07-17|Packard Bell Nec, Inc.|Mouse emulation with a passive pen|
    US5974558A|1994-09-02|1999-10-26|Packard Bell Nec|Resume on pen contact|
    US5867106A|1994-09-02|1999-02-02|Packard Bell Nec|Password switch to override remote control|
    US6137473A|1994-09-02|2000-10-24|Nec Corporation|System and method for switching control between a host computer and a remote interface device|
    US6292181B1|1994-09-02|2001-09-18|Nec Corporation|Structure and method for controlling a host computer using a remote hand-held interface device|
    US5754584A|1994-09-09|1998-05-19|Omnipoint Corporation|Non-coherent spread-spectrum continuous-phase modulation communication system|
    US5953370A|1994-09-09|1999-09-14|Omnipoint Corporation|Apparatus for receiving and correlating a spread spectrum signal|
    US5832028A|1994-09-09|1998-11-03|Omnipoint Corporation|Method and apparatus for coherent serial correlation of a spread spectrum signal|
    US5692007A|1994-09-09|1997-11-25|Omnipoint Corporation|Method and apparatus for differential phase encoding and decoding in spread-spectrum communication systems with continuous-phase modulation|
    US5856998A|1994-09-09|1999-01-05|Omnipoint Corporation|Method and apparatus for correlating a continuous phase modulated spread spectrum signal|
    US5610940A|1994-09-09|1997-03-11|Omnipoint Corporation|Method and apparatus for noncoherent reception and correlation of a continous phase modulated signal|
    US5680414A|1994-09-09|1997-10-21|Omnipoint Corporation|Synchronization apparatus and method for spread spectrum receiver|
    US5648982A|1994-09-09|1997-07-15|Omnipoint Corporation|Spread spectrum transmitter|
    US5659574A|1994-09-09|1997-08-19|Omnipoint Corporation|Multi-bit correlation of continuous phase modulated signals|
    US5627856A|1994-09-09|1997-05-06|Omnipoint Corporation|Method and apparatus for receiving and despreading a continuous phase-modulated spread spectrum signal using self-synchronizing correlators|
    US5881100A|1994-09-09|1999-03-09|Omnipoint Corporation|Method and apparatus for coherent correlation of a spread spectrum signal|
    US5963586A|1994-09-09|1999-10-05|Omnipoint Corporation|Method and apparatus for parallel noncoherent correlation of a spread spectrum signal|
    US5629956A|1994-09-09|1997-05-13|Omnipoint Corporation|Method and apparatus for reception and noncoherent serial correlation of a continuous phase modulated signal|
    US5754585A|1994-09-09|1998-05-19|Omnipoint Corporation|Method and apparatus for serial noncoherent correlation of a spread spectrum signal|
    US5757847A|1994-09-09|1998-05-26|Omnipoint Corporation|Method and apparatus for decoding a phase encoded signal|
    US5553126A|1995-01-20|1996-09-03|Gte Laboratories Incorporated|Secure anti-jamming wireless party line|
    US5745484A|1995-06-05|1998-04-28|Omnipoint Corporation|Efficient communication system using time division multiplexing and timing adjustment control|
    US5959980A|1995-06-05|1999-09-28|Omnipoint Corporation|Timing adjustment control for efficient time division duplex communication|
    US5689502A|1995-06-05|1997-11-18|Omnipoint Corporation|Efficient frequency division duplex communication system with interleaved format and timing adjustment control|
    US6041046A|1995-07-14|2000-03-21|Omnipoint Corporation|Cyclic time hopping in time division multiple access communication system|
    US6018806A|1995-10-16|2000-01-25|Packard Bell Nec|Method and system for rebooting a computer having corrupted memory using an external jumper|
    US6005533A|1995-10-16|1999-12-21|Packard Bell Nec|Remote occlusion region|
    US6963783B1|1995-10-16|2005-11-08|Packard Bell Nec|Audio compression in a wireless remote interface tablet|
    US6108727A|1995-10-16|2000-08-22|Packard Bell Nec|System having wireless interface device for storing compressed predetermined program files received from a remote host and communicating with the remote host via wireless link|
    US6141688A|1995-10-16|2000-10-31|Nec Corporation|Broadcast search for available host|
    US5990875A|1995-10-16|1999-11-23|Packard Bell Nec|Double pen up event|
    US6664982B1|1995-10-16|2003-12-16|Nec Corporation|Multi-user on-screen keyboard|
    US6279153B1|1995-10-16|2001-08-21|Nec Corporation|Multi-user flash ROM update|
    US5996082A|1995-10-16|1999-11-30|Packard Bell Nec|System and method for delaying a wake-up signal|
    US7512671B1|1995-10-16|2009-03-31|Nec Corporation|Computer system for enabling a wireless interface device to selectively establish a communication link with a user selectable remote computer|
    US6126327A|1995-10-16|2000-10-03|Packard Bell Nec|Radio flash update|
    JPH09307951A|1996-03-15|1997-11-28|Matsushita Electric Ind Co Ltd|Spread spectrum communication equipment|
    CN1108034C|1996-06-27|2003-05-07|Ntt移动通信网株式会社|Radio calling system|
    WO1998010535A1|1996-09-06|1998-03-12|Karl Wagner|Wireless communications system using beam direction multiplexing|
    JP3317866B2|1996-12-20|2002-08-26|富士通株式会社|Spread spectrum communication system|
    US6275704B1|1997-03-03|2001-08-14|Xircom, Inc.|Multiple access communication system with polarized antennas|
    US6272121B1|1997-03-03|2001-08-07|Omnipoint Corporation|Spread spectrum communication system using DECT protocol|
    US6085076A|1997-04-07|2000-07-04|Omnipoint Corporation|Antenna diversity for wireless communication system|
    US5970095A|1997-04-14|1999-10-19|Lockheed Martin Corporation|Secure data transmission on a TDM isochronous network|
    US6005854A|1997-08-08|1999-12-21|Cwill Telecommunication, Inc.|Synchronous wireless access protocol method and apparatus|
    US6088659A|1997-09-11|2000-07-11|Abb Power T&D Company Inc.|Automated meter reading system|
    US6580906B2|1997-12-10|2003-06-17|Intel Corporation|Authentication and security in wireless communication system|
    US6097817A|1997-12-10|2000-08-01|Omnipoint Corporation|Encryption and decryption in communication system with wireless trunk|
    US8165028B1|1997-12-10|2012-04-24|Intel Corporation|Monitoring in communication system with wireless trunk|
    US6526026B1|1997-12-10|2003-02-25|Intel Corporation|Digit transmission over wireless communication link|
    US6208627B1|1997-12-10|2001-03-27|Xircom, Inc.|Signaling and protocol for communication system with wireless trunk|
    JP3233947B2|1998-05-07|2001-12-04|株式会社エヌ・ティ・ティ・ドコモ|Spreading signal allocation method and signal transmission method in direct spread CDMA mobile communication system, mobile radio communication system using these methods, and transmitter, receiver and transmission / reception device of this mobile radio communication system|
    US6563856B1|1998-07-08|2003-05-13|Wireless Facilities, Inc.|Frame synchronization and detection technique for a digital receiver|
    US6700902B1|1998-10-19|2004-03-02|Elster Electricity, Llc|Method and system for improving wireless data packet delivery|
    DE19911712A1|1999-03-16|2000-10-05|Siemens Ag|Transmission method with variable data rate in a RACH channel of a radio communication system|
    US6324209B1|2000-02-28|2001-11-27|Golden Bridge Technology Inc.|Multi-channel spread spectrum system|
    DE10240322B4|2002-08-31|2004-08-26|Schwan-Stabilo Cosmetics Gmbh & Co. Kg|Preparation containing lipids and their use|
    US20040203976A1|2002-12-30|2004-10-14|Gupta Vivek G.|Power management for nodes coupled to a communication link|
    US7702594B2|2004-09-24|2010-04-20|Elster Electricity, Llc|System and method for automated configuration of meters|
    US7742430B2|2004-09-24|2010-06-22|Elster Electricity, Llc|System for automated management of spontaneous node migration in a distributed fixed wireless network|
    US8073384B2|2006-12-14|2011-12-06|Elster Electricity, Llc|Optimization of redundancy and throughput in an automated meter data collection system using a wireless network|
    US8320302B2|2007-04-20|2012-11-27|Elster Electricity, Llc|Over the air microcontroller flash memory updates|
    NZ586190A|2007-12-26|2013-05-31|Elster Electricity Llc|A utility meter network wherein meters can transmit electrical and other readings to a collector by using other meters as repeaters|
    US8525692B2|2008-06-13|2013-09-03|Elster Solutions, Llc|Techniques for limiting demand from an electricity meter with an installed relay|
    US8203463B2|2009-02-13|2012-06-19|Elster Electricity Llc|Wakeup and interrogation of meter-reading devices using licensed narrowband and unlicensed wideband radio communication|
    US10931909B2|2018-09-18|2021-02-23|Roku, Inc.|Wireless audio synchronization using a spread code|
    US10992336B2|2018-09-18|2021-04-27|Roku, Inc.|Identifying audio characteristics of a room using a spread code|
    US10958301B2|2018-09-18|2021-03-23|Roku, Inc.|Audio synchronization of a dumb speaker and a smart speaker using a spread code|
    US20210345183A1|2018-10-10|2021-11-04|Kyocera Corporation|Cdma based reservation channel transmission in v2v communications|
    法律状态:
    2002-07-22| AS| Assignment|Owner name: INTEL CORPORATION, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:XIRCOM WIRELESS, INC.;REEL/FRAME:013111/0961 Effective date: 20020613 |
    2003-08-07| AS| Assignment|Owner name: XIRCOM II WIRELESS, INC., COLORADO Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:INTEL CORPORATION;REEL/FRAME:014327/0157 Effective date: 20021227 |
    2003-08-28| AS| Assignment|Owner name: INTEL CORPORATION, CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:XIRCOM II WIRELESS, INC.;REEL/FRAME:014420/0537 Effective date: 20030821 |
    2012-03-26| REMI| Maintenance fee reminder mailed|
    2012-08-12| LAPS| Lapse for failure to pay maintenance fees|
    2012-09-10| STCH| Information on status: patent discontinuation|Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
    2012-10-02| FP| Expired due to failure to pay maintenance fee|Effective date: 20120812 |
    优先权:
    申请号 | 申请日 | 专利标题
    US60077290A| true| 1990-10-23|1990-10-23||
    US95745792A| true| 1992-10-05|1992-10-05||
    US08/161,187|US5455822A|1990-10-23|1993-12-03|Method and apparatus for establishing spread spectrum communication|
    US53643295A| true| 1995-09-29|1995-09-29||
    US08/767,152|US5737324A|1990-10-23|1996-12-16|Method and apparatus for establishing spread spectrum communication|
    US77514696A| true| 1996-12-31|1996-12-31||
    US09/731,329|US7411936B2|1990-10-23|2000-12-05|Wireless communication method and apparatus|US09/731,329| US7411936B2|1990-10-23|2000-12-05|Wireless communication method and apparatus|
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