• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    An object of the present invention is to extract the energy of each FSK frequency component using a multi-stage energy detector in the synchronous acquisition of a demodulator that demodulates an FSK-modulated signal, thereby avoiding synchronous acquisition failure that may occur due to noise. Reduce the likelihood and increase the effectiveness of motivation acquisition. The configuration of the present invention, the PN code generator 10 for generating a PN code; A frequency oscillator 20 generating a frequency corresponding to a code generated by the PN code generator 10; A frequency mixer (30) which receives the signal output from the frequency oscillator (20), mixes and outputs the frequency signal transmitted from the other side and input; A multi-stage band pass filter 40 which receives a signal output from the frequency mixer 30 and passes only a frequency required for synchronization acquisition; A multi-stage energy detector (50) which receives the signal output from the band pass filter (40) and detects and outputs energy; An adder (60) for adding all of the signals output from the multi-stage energy detector (50); An integrator (70) for receiving the signal output from the adder (60) and integrating and outputting the signal; A comparator (80) which receives the signal output from the integrator (70) and compares it with a preset threshold voltage and outputs the corresponding signal; The PN code driver 90 receives the signal output from the comparator 80 and drives the PN code generator 10 according to the value.
    公开号:KR20000042960A
    申请号:KR1019980059258
    申请日:1998-12-28
    公开日:2000-07-15
    发明作者:김창기
    申请人:서평원；엘지정보통신 주식회사；
    IPC主号:
    专利说明:

    Frequency Shift Keying Demodulator Synchronous Acquisition Circuit Using Multistage Energy Detection
    The present invention relates to a frequency shift keying (FSK) demodulator synchronous acquisition circuit through multi-stage energy detection. More specifically, the present invention relates to a synchronous acquisition of a demodulator for demodulating a signal input by FSK modulation. By using the multi-stage energy detector, the energy of each FSK frequency component is extracted, thereby reducing the possibility of synchronization acquisition failure caused by noise and increasing the effect of the synchronization acquisition. A keying demodulator synchronous acquisition circuit.
    The FSK modulation scheme is a modulation scheme that transmits information by changing a carrier frequency according to a user's data sequence. When demodulating an FSK modulated signal, an FSK demodulation scheme is required. In FSK demodulation, synchronization is important.
    Hereinafter, a conventional FSK synchronization acquisition circuit will be described with reference to the accompanying drawings.
    As shown in Fig. 1, the configuration of the conventional FSK synchronization acquisition circuit is
    A PN code generator 12 operating according to an input clock signal to generate a PN code such as an FSK modulator;
    A frequency oscillator 13 generating a frequency corresponding to a code generated by the PN code generator 12;
    A clock generator 11 generating and providing a clock signal to the PN code generator 12;
    A frequency mixer (14) which receives a signal output from the frequency oscillator (13), mixes with a frequency signal transmitted and input from the other side and outputs a frequency signal accordingly;
    A bandpass filter (BPF) which receives a signal output from the frequency mixer 14 and passes only a frequency band signal necessary for synchronization acquisition;
    An energy detector 16 which receives a signal output from the band pass filter 15 and detects energy and outputs a signal accordingly;
    And a comparator 17 for receiving a signal output from the energy detector 16 and comparing it with a threshold voltage Vth of a predetermined magnitude, thereby outputting a signal for driving the clock generator 11.
    The operation of the conventional FSK synchronization acquisition circuit made as described above is as follows.
    The PN code generator 12 operates according to an input clock signal, generates and outputs a PN code such as an FSK modulator, and the frequency oscillator 13 has a frequency corresponding to a code generated by the PN code generator 12. Generate and print
    On the other hand, the clock generator 11 operates according to a driving signal to be turned on / off to generate and provide a clock signal to the PN code generator 12.
    The frequency mixer 14 receives a signal output from the frequency oscillator 13, mixes with a frequency signal transmitted and input from the other side, and outputs a frequency signal accordingly.
    The band pass filter 15 receives the signal output from the frequency mixer 14 and passes only the frequency band signals necessary for synchronization acquisition, and the energy detector 16 receives the signal output from the band pass filter 15. Detects energy and outputs the signal accordingly.
    The comparator 17 receives the signal output from the energy detector 16 and compares it with a threshold voltage Vth of a predetermined magnitude and outputs a signal for driving the clock generator 11 accordingly, thereby outputting a clock generator 11. ) On / off.
    First, when the system is turned on, the clock generator 11 is in an off state, and thus the PN code generator 12 continues to maintain the same PN code value until the clock generator 11 is turned on. The frequency output from the frequency oscillator 13 is fixed at one hopping frequency.
    In this process, when the hopping frequency of the input signal coincides with the hopping frequency of the receiver, the output of the energy detector 16 is output above the threshold value, and accordingly the high signal is output from the comparator 17, so that the clock generator ( 11) is turned on.
    When the clock generator 11 is turned on, the PN code output from the PN code generator 12 is generated according to its sequence, from which time the hopping frequency of the input signal and the frequency oscillator 13 continue. Synchronization is obtained by matching with the hopping frequency output from
    However, in the conventional FSK synchronization acquisition circuit operating as described above, all the m FSK frequencies passing through the frequency mixer 14 pass through the band pass filter 15, thereby spreading the energy widely, so that the energy detector 16 The probability of error occurrence during detection increases, which increases the probability of failing synchronization acquisition.
    Accordingly, an object of the present invention is to solve the problems of the prior art as described above. In the synchronous acquisition of a demodulator for demodulating a signal input by FSK modulation, energy of each FSK frequency component is obtained by using a multi-stage energy detector. By extracting each, it is possible to provide a frequency shift keying demodulator synchronous acquisition circuit through multi-stage energy detection that can reduce the possibility of synchronization acquisition failure that may be caused by noise and enhance the effect of synchronous acquisition.
    1 is a block diagram applying a frequency keying demodulator synchronous acquisition circuit of the prior art;
    2 is a block diagram of a frequency shift keying demodulator synchronous acquisition circuit using multi-stage energy detection according to an embodiment of the present invention.
    Explanation of symbols on the main parts of the drawings
    10: PN code generator 20: frequency oscillator 30: frequency mixer
    40 band pass filter 50 energy detector 60 adder
    70: integrator 90: PN code driver 80: integrator
    The configuration of the present invention for achieving the above object is made as follows.
    PN code generating means for generating a PN code such as an FSK modulator;
    Frequency oscillating means for generating a frequency corresponding to a code generated by said PN code generating means;
    Frequency mixing means for receiving a signal output from the frequency oscillating means, mixing the frequency signal transmitted from the other side and inputting the frequency signal;
    Band pass filtering means for receiving a signal output from the frequency mixing means and passing only a frequency band signal necessary for synchronization acquisition;
    Energy detecting means for receiving the signal output from the band pass filtering means, detecting energy, and outputting a signal accordingly;
    In the FSK synchronization acquisition circuit comprising a PN code driving means for receiving a signal output from the energy detecting means and comparing it with a threshold voltage of a predetermined magnitude, thereby outputting a signal for driving the PN code generating means.
    The band pass filtering means is configured in multiple stages corresponding to the number of hopping frequencies,
    The energy detecting means is configured in multiple stages corresponding to the number of hopping frequencies,
    And adding means for adding and outputting all the output signals of the multi-stage of the energy detecting means,
    And integrating means for receiving the signal output from the adding means and integrating the signal output to the PN code driving means.
    Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
    As shown in Figure 2, the configuration of the frequency shift keying demodulator synchronous acquisition circuit through the multi-stage energy detection according to an embodiment of the present invention is as follows.
    A PN code generator 10 generating a PN code such as an FSK modulator;
    A frequency oscillator 20 generating a frequency corresponding to a code generated by the PN code generator 10;
    A frequency mixer (30) which receives a signal output from the frequency oscillator (20), mixes with a frequency signal transmitted and input from the other side and outputs a frequency signal accordingly;
    A band pass filter 40 configured to receive a signal output from the frequency mixer 30 and have a multi-stage corresponding to a hopping frequency to pass only a frequency band signal necessary for synchronization acquisition;
    An energy detector configured to receive a signal output from the band pass filter 40 to detect energy and output a signal according to the multi-stage;
    An adder (60) for adding all of the signals output from the multi-stage energy detector (50);
    An integrator (70) for receiving the signal output from the adder (60) and integrating and outputting the signal;
    A comparator (80) which receives the signal output from the integrator (70) and compares it with a preset threshold voltage to determine whether synchronization has been acquired and output a signal accordingly;
    And a PN code driver 90 which receives a signal output from the comparator 80 and outputs a signal for driving the PN code generator 10 according to the value thereof.
    Operation of the embodiment of the present invention made as described above is as follows.
    The m-FSK modulated signal is inputted with frequency hopping according to the sequence of PN codes. This circuit is a system that acquires synchronization by finding the hopping sequence of the transmission frequency. The frequency of each of the m-FSK modulated signals is obtained. It is characterized by integrating after detecting and summing the energy of the band.
    Referring to the operation of each part of the circuit, the PN code generator 10 generates and outputs the same PN code as the FSK modulator, and the frequency oscillator 20 corresponds to the code generated by the PN code generator 10. Generate and output a frequency.
    In addition, the frequency mixer 30 receives the signal output from the frequency oscillator 20, mixes with the frequency signal transmitted and input from the other side and outputs the frequency signal accordingly, the band pass filter 40 is multi-stage It is configured to receive the signal output from the frequency mixer 30 and passes only the frequency band signal necessary for the acquisition as much as the frequency of hopping.
    The energy detector 50 is also configured in multiple stages, respectively, and receives the signal output from the band pass filter 40 to detect energy and output a signal accordingly.
    The adder 60 adds and outputs all the signals output from the multi-stage energy detector 50, and the integrator 70 receives the signals output from the adder 60, integrates them, and outputs the comparator 80. By receiving the signal output from the integrator 70 and comparing it with a preset threshold voltage, it is determined whether or not synchronization is acquired and outputs the signal accordingly.
    The PN code driver 90 receives a signal output from the comparator 80 and outputs a signal for driving the PN code generator 10 according to the value.
    As described above, the operation of each component is performed. In the earthenware in which the circuit is operated, the PN code generator 10 continuously generates only one PN code until synchronization is obtained, thus outputting the frequency oscillator 20. Only one frequency is maintained.
    The signal output from the frequency oscillator 20 and the frequency signal transmitted and input from the outside are multiplied with each other through the frequency mixer 30, and the multiplied signals are divided into m frequency signals and bands corresponding to each frequency band. Input to the band pass filter 41, 41, ..., 4M in the pass filter 40, all components except the corresponding frequency components are removed.
    The signals output from the band pass filters 41, 41,..., 4M in the band pass filter 40 are respectively passed through the respective energy detectors 51, 52,..., 5M of the energy detector 50. Energy is detected.
    If the transmitted and input signal continues frequency hopping and coincides with the frequency output from the frequency oscillator 20, energy is detected at any one of the m energy detectors 51, 52, ..., 5M. The adder 60 adds all of the signals output from the respective energy detectors 51, 52,..., 5M to sum the detection results, and the integrator 70 adds the adder during the frequency hopping period. Integrate the signal output from 60).
    The signal output from the integrator 70 is compared with a threshold voltage Vth preset by the comparator 80, so that a signal according to energy detection is output. If energy is not detected, the comparator ( Since the voltage of the signal input to 80 is smaller than the threshold voltage Vth, the output signal of the comparator 80 becomes logical '0', and if energy is detected, the voltage of the signal input to the comparator 80 Since it is larger than the threshold voltage Vth, the output signal of the comparator 80 becomes logical '1'.
    When the signal output from the comparator 80 becomes a logical '0', the value is converted to a logical '1' through an inverter 91 of the PN code driver 90 and the value is an orgate. The PN code generator 10 is input to the PN code generator 10 via an OR gate 92 and through a retarder 93, thereby holding the PN code generator 10. The output value of is maintained.
    However, when the signal output from the comparator 80 becomes a logical '1', the value becomes the logical '0' through the inverter 91 of the PN code driver 90 and the value is an orgate. After passing through (92) and through the delay (93) to the PN code generator 10, the PN code generator 10 generates the PN code sequentially according to the value to be continuously synchronized do.
    For the m-FSK frequency signal as described above, each bandpass filter and energy detector are allocated to each FSK frequency to extract the energy of each FSK frequency component, so that it is generated more synchronously than before. The energy can be detected.
    In addition, by independently operating as described above, noise generated on a channel or in a circuit can be diffused to a large area through an integrator, thereby diluting its influence, thereby preventing errors due to noise, and thus obtaining accurate synchronization effects. It can increase.
    The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, conversions, and modifications are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have knowledge.
    Therefore, in the present invention operating as described above, in synchronizing acquisition of a demodulator for demodulating an input signal that is FSK-modulated, the energy of each FSK frequency component may be extracted by using a multi-stage energy detector. It has the effect of reducing the possibility of motivation acquisition and enhancing the effectiveness of motivation acquisition.
    权利要求:
    Claims (1)
    [1" claim-type="Currently amended] PN code generating means for generating a PN code such as an FSK modulator;
    Frequency oscillating means for generating a frequency corresponding to a code generated by said PN code generating means;
    Frequency mixing means for receiving a signal output from the frequency oscillating means, mixing the frequency signal transmitted from the other side and inputting the frequency signal;
    Band pass filtering means for receiving a signal output from the frequency mixing means and passing only a frequency band signal necessary for synchronization acquisition;
    Energy detecting means for receiving the signal output from the band pass filtering means, detecting energy, and outputting a signal accordingly;
    In the FSK synchronization acquisition circuit comprising a PN code driving means for receiving a signal output from the energy detecting means and comparing it with a threshold voltage of a predetermined magnitude, thereby outputting a signal for driving the PN code generating means.
    The band pass filtering means is configured in multiple stages corresponding to the number of hopping frequencies,
    The energy detecting means is configured in multiple stages corresponding to the number of hopping frequencies,
    And adding means for adding and outputting all the output signals of the multi-stage of the energy detecting means,
    And integrating means for receiving the signal outputted from the adding means and integrating the signal outputted to the PN code driving means.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1998-12-28|Application filed by 서평원, 엘지정보통신 주식회사
    1998-12-28|Priority to KR1019980059258A
    2000-07-15|Publication of KR20000042960A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019980059258A|KR20000042960A|1998-12-28|1998-12-28|Sync obtaining circuit of frequency shift keying demodulator via step energy detection|
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