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    • 专利摘要:
    transmitting apparatus, receiving apparatus, method of transmission, method of reception, and method for generating multidirectional constellations. the present invention relates to digital data communication and provides an efficient method for the generation of multidimensional constellations for modulating digital data with a high modulus of diversity of modulation, a method for transmitting and receiving data based on such constellations, and one device matches. this is achieved by considering only multidirectional rotation matrices with all elements on the diagonal having the same first absolute value and all other elements having the same second absolute value. thus, multidirectional rotation matrices can be generated having only a single independent parameter and a structure that is as regular as possible. the independent parameter can be configured to minimize the probability of error for various constellation sizes.
    公开号:BR112012003377B1
    申请号:R112012003377-8
    申请日:2010-08-17
    公开日:2021-03-23
    发明作者:Mihail Petrov；Tomohiro Kimura
    申请人:Sun Patent Trust；
    IPC主号:
    专利说明:

    [0001] [0001] The present invention relates to digital data communication, in particular to methods for generating multidimensional constellations for modulating digital data, methods for modulating and transmitting data based on multidimensional constellations, and a corresponding apparatus. Background of the Technique
    [0002] [0002] Fading is one of the main problems in communication systems. It represents the random fluctuations in the amplitude of the received signal due to the propagation of multiple paths. If the delay spread of the channel is greater than the signal symbol period, the fade is also selective in terms of frequency. The extent of fading is usually approximated by a Rayleigh distribution. Such fading is referred to as Rayleigh fading.
    [0003] [0003] In digital communication systems, information is encoded as a sequence of symbols belonging to a discrete alphabet, referred to as a constellation. Such a constellation has N dimensions and encodes B bits of information per dimension. The number of possible values, also referred to as constellation points, is therefore 2N * B. The number of bits per dimension B directly determines the spectral efficiency of the transmission, given in bits / Hz. The number of dimensions N has no effect on spectral efficiency. An illustrative constellation with N = 2 and B = 1 is shown in figure 1a.
    [0004] [0004] Traditionally, for example, in a QAM constellation illustrated in figure 1a, each transmitted bit affects only one dimension. With reference to figure 1a, "b1" for each constellation point "b1b2" (= "00", "01", "10", and "11") affects only the dimension represented by the horizontal geometric axis, whereas " b2 "from each constellation point" b1b2 "affects only the dimension represented by the vertical geometric axis. If the dimension affected by the transmitted bits undergoes a deep fade, all the bits that modulate that dimension will be extremely unreliable, which increases the probability of error. This effect is illustrated by errors in figure 1a. For example, if the channel represented by the vertical geometric axis fades, the constellation points "00", "01", "10" and "11" will approach the horizontal geometric axis (along the solid arrows in figure 1a). As a result, the constellation points "00" and "01", in addition to the constellation points "10" and "11" will not be discernible.
    [0005] [0005] If the constellation is modified so that each bit affects all dimensions, the resilience of the fade is increased. A deep fade in one of the dimensions will affect every bit of the constellation; however, this effect will not be harmful as in the conventional case, so that on average, the probability of error decreases. This is referred to in the literature as modulation diversity. Rotated Constellations
    [0006] [0006] One way to achieve modulation diversity is to rotate a constellation (hypercubic) to spread the effect of a channel fade across all its dimensions. This is illustrated in figure 1b for the case where N = 2 and B = 1. For example, as illustrated in figure 1b, if the channel represented by the vertical geometric axis fades, the constellation points "00", "01", "10" and "11" will approach the horizontal geometric axis (along the solid arrows of figure 1b). However, these constellation points will still be discernible in the dimension represented by the horizontal geometric axis. As such, the constellation points "00", "01", "10" and "11" remain discernible even after a deep fading of the channel represented by the vertical geometric axis.
    [0007] [0007] A multidimensional rotation can be achieved by multiplying the element signal vector N by a square matrix N * N. The necessary and sufficient condition for a square matrix to be a rotation matrix (or a reflex matrix) is that it is orthogonal, that is, it satisfies the equation of mathematics 1 below. Mathematics 1 RRT = I
    [0008] [0008] Note that in mathematics 1 above, the matrix R is a square matrix, the matrix RT is the matrix transposition matrix R and the matrix I it is a unitary matrix.
    [0009] [0009] This means that with respect to mathematics 1 above, the row / column vectors must be orthogonal unit vectors, that is, they must satisfy the mathematics 2 equation below. Mathematics 2
    [0010] [00010] Note that in Mathematics 2, δj, k = 1 if j = k and δj, k = 0 if j ≠ k
    [0011] [00011] This preserves the Euclidean distance between any two points in the constellation and ensures that performance on channels with additional white Gaussian noise (AWGN channels) is not affected.
    [0012] [00012] Obviously, not all rotations result in an improved modulation diversity effect. From NPL 1, it is known that the ideal rotation angle θ for 16-QAM it satisfies the equation illustrated in Mathematics 3 below. The corresponding 2D (two-dimensional) rotation matrix R satisfies the equation illustrated in Mathematics 4 below. Mathematics 3 θ = π / 8 Mathematics 4
    [0013] [00013] Finding the ideal rotation for constellations of more than two dimensions is more complicated, since there is no single optimization parameter such as that pertaining to the rotation angle in a 2D constellation. In the case of a 4D constellation, for example, there are six independent rotation angles, each with its own partial rotation matrix. The partial rotation angles are also called Givens angles in NPL 2. The final 4D rotation matrix is obtained by multiplying six Givens rotation matrices, that is, six matrices illustrated in Mathematics 5 below. Mathematics 5
    [0014] [00014] From NPL2, it is known that the optimization can be performed through the vector having the six elements illustrated in Mathematics 6 below. Mathematics 6 θ = (θ1,2, θ1,3, θ1,4, θ2,3, θ2,4, θ3,4)
    [0015] [00015] According to NPL 2, the resulting ideal rotation angles for a 4D constellation with two bits per dimension have values illustrated in Mathematics 7 below. Mathematics 7
    [0016] [00016] The disadvantage of this method is the number of parameters, specifically for a large number of dimensions. For N dimensions, the number of partial rotation angles is equal to the number of possible combinations of two in a set of N, that is, the value provided by Mathematics 8 below. Mathematics 8
    [0017] [00017] In this way, the number of rotation angles increases with the square of the number of dimensions, so that the optimization problem becomes very difficult when the number of dimensions is large.
    [0018] [00018] NPL 3 describes two different approaches, based on the use of algebraic number theory, which has the advantage of a reduced number of parameters.
    [0019] [00019] The first approach allows the construction of rotation matrices by applying "canonical inlay" in an algebraic numeric field. Two methods are proposed. The first method produces trusses with diversity L = N / 2 for the number of dimensions N = 2e23e3, with e2, e3 = 0, 1, 2, ... Diversity means the minimum number of different values in the components of any two distinct points of the constellation. The second method produces trusses with diversity L = N. The possible values of N are very limited, such as 3, 5, 9, 11 and 15.
    [0020] [00020] A variation of this method for generating N dimensional rotated constellations is also known from NPL 3. The rotation matrix R is expressed by Mathematics 9 below. Mathematics 9
    [0021] [00021] Note that the superscript letter "T" denotes the transposition of a matrix.
    [0022] [00022] For N = 4, the value of the rotation matrix R is provided by Mathematics 10 below. Mathematics 10
    [0023] [00023] Although the resulting rotation matrix is a rotation matrix that is orthogonal to any N, the total modulation diversity is only achieved when N is a power of two.
    [0024] [00024] Each of these methods can guarantee a certain degree of diversity. However, the resulting rotation matrix is fixed, not having any parameter that allows the optimization of different constellation sizes. Therefore, a severe disadvantage of these methods is that the effect of the modulation diversity cannot be maximized according to different constellation sizes.
    [0025] [00025] The second approach first builds the rotation matrices with two and three dimensions, which can be used as base matrices for the construction of matrices with more dimensions using a stacked expansion type Hadamard illustrated in Mathematics 11 below. Mathematics 11
    [0026] [00026] The 2D and 3D rotation matrices have a single independent parameter that is chosen so that the final distance of the constellation is maximized. A 4D rotation matrix is constructed from two 2D matrices according to Mathematics 11 above. Due to the small relative size, it is possible to find an algebraic relationship between the parameters of the two 2D rotation matrices so that the final distance is maximized. For larger dimensions, such optimization becomes intractable, which is the main disadvantage of the second approach. Constellation Components Mapping to Ensure Independent Fading
    [0027] [00027] Another aspect refers to the separation and mapping of the N dimensions of the rotated constellation so that they undergo independent fading. This is a key aspect necessary to achieve the expected diversity performance.
    [0028] [00028] The N constellation components, which are obtained by separating N dimensional rotational constellations based on dimension, can be transmitted through different time partitions, frequencies, transmitting antennas, or combinations thereof. Additional signal processing is possible before transmission. The critical aspect is that the fading suffered by each of the N dimensions must be different from, or ideally not correlated with, the fading suffered by any other of the N dimensions.
    [0029] [00029] The spreading of the N dimensions across the different time partitions, frequencies and antennas can be achieved, for example, through the appropriate interleaving and mapping. Constellation Components Mapping for Transmitted Complex Cells
    [0030] [00030] Another aspect refers to the mapping of N real dimensions of the rotated constellation to complex symbols for transmission. In order to guarantee the desired diversity, the N dimensions must be mapped into different complex symbols. The complex symbols are then spread as described above, for example, through interleaving and mapping, so that at reception, the fading suffered by each of the N dimensions is not correlated with the fading of another of the N dimensions.
    [0031] [00031] Figure 2 is a block diagram of a transmission device.
    [0032] [00032] The transmission apparatus consists of an FEC 210 encoder, a bit interleaver 220, a rotated constellation mapper 230, a complex symbol mapper 240, an interleaver / symbol mapper 250, modulation currents 260-1 to 260-M, and transmitting antennas 270-1 to 270-M.
    [0033] [00033] The FEC 210 encoder performs the forward error correction (FEC) coding at the input. Note that the best FEC codes known to date, which are also the most used in the new standards, are the turbo codes and the low density parity check (LDPC) codes.
    [0034] [00034] Bit interleaver 220 performs bit interleaving at the input from the FEC 210 encoder. Here, the bit interleaving can be block interleaving or convolute interleaving.
    [0035] [00035] The rotated constellation mapper 230 maps the input of bit interleaver 220 to the rotated constellation.
    [0036] [00036] Generally, the input to the rotated constellation mapper 230 exits the FEC 210 encoder through bit interleaver 220 that performs optional bit interleaving. Bit interleaving is usually necessary when there is more than one bit per dimension (B> 1). The FEC coding performed by the FEC 210 encoder introduces redundant bits in a controlled manner, so that propagation errors can be corrected in the receiving apparatus. Although the overall spectral efficiency decreases, the transmission generally becomes more robust, that is, the bit error rate (BER) drops much faster with the signal-to-noise ratio (SNR).
    [0037] [00037] Note that with respect to the original mapping of information bits in the non-rotated hypercube constellations, each dimension is modulated separately by B bits, using binary or Gray mapping, so that the number of discrete values is equal to 2B and the number of constellation points is 2B * N.
    [0038] [00038] Complex symbol mapper 240 maps each of the N constellation components, which represent N dimensional rotated constellation symbols that enter from the rotated constellation mapper 230, to a different symbol among the complex symbols.
    [0039] [00039] There are multiple possibilities for the mapping carried out by the complex symbol mapper 240, that is, the mapping of each of the N constellation components, which represent the N dimensional rotated constellation symbols to a different symbol among the complex symbols. Some of these possibilities are illustrated in figure 3. The essential function of the complex symbol mapper 240 is to map each of the N constellation components of a rotated constellation symbol to a different symbol among the complex symbols.
    [0040] [00040] By way of example, figure 3 illustrates the case of four dimensions. Referring to Figure 3, the boxes showing the same number (for example, "1") represent a group of 4D rotated constellation symbols. The number shown in each box indicates the group number of the corresponding group. In addition, each box indicates a one-dimension constellation component.
    [0041] [00041] Illustrated below "Constellation Symbols" in figure 3 is a state in which six groups of 4D rotated constellation symbols are aligned. Illustrated below "Complex Symbols" in figure 3, there are twelve complex symbols, which are obtained by the new arrangement of six groups of rotated constellation symbols 4D illustrated below "Constellation Symbols" in figure 3. Note that the figure 3 illustrates three forms of "Complex Symbols" as examples. At the time of actual transmission, a pair of two constellation components that are vertically aligned under "complex symbols" (the result of the new arrangement) are modulated and transmitted as a complex symbol.
    [0042] [00042] The symbol interleaver / mapper 250 performs symbol interleaving on the complex symbols that enter from the complex symbol mapper 240, and thereafter maps the complex symbols on different time partitions, frequencies, transmitting antennas, or combinations. Here, the symbol interleaving can be block interleaving or convolute interleaving.
    [0043] [00043] The modulation currents 260-1 to 260-M are provided in a one-to-one correspondence with the transmitting antennas 270-1 to 270-M. Each of the 260-aa 260-M modulation currents inserts pilots to estimate the fading coefficients at the corresponding input from the 250 symbol mapper / interleaver, and also performs various processing, such as time domain conversion, digital conversion for analog (D / A), transmission filtering and orthogonal modulation, at the corresponding input. Then, each of the modulation currents 260-1 to 260-M transmits the transmission signal through a corresponding antenna between the transmitting antennas 270-1 to 270-M. Receiver Side
    [0044] [00044] On the receiver side, the exact inversion steps of the steps performed by the transmission device must be performed. Figure 4 illustrates a block diagram of a receiving apparatus corresponding to the transmission apparatus whose block diagram is illustrated in figure 2.
    [0045] [00045] The receiving apparatus consists of receiving antennas 410-1 to 410-M, demodulation currents 420-1 to 420-M, a demapper / deinterleaver 430, a complex demapper 440, a constellation demapper rotated 450, a 460 bit deinterleaver, and an FEC 470 decoder.
    [0046] [00046] Demodulation currents 420-1 to 420-M are provided in a one-to-one correspondence with receiver antennas 410-a to 410-M. Each of the demodulation currents 420-1 to 420-M performs processing such as A / D conversion, reception filtering and orthogonal demodulation in the signal transmitted by the transmission apparatus of figure 2 and received by a corresponding receiving antenna 410-1 a 410-M. Then, demodulation currents 420-1 to 420-M estimate (i) the amplitude values (fading coefficients) of the channel characteristics by using pilots and (ii) noise variation, and output of the estimated amplitude values and noise variation along with the received phase-corrected signal.
    [0047] [00047] The symbol demapper / deinterleaver 430 performs the processing inverted to the processing performed by the symbol interleaver / mapper 230 on the transmission apparatus at the inputs from demodulation currents 420-1 to 420-M.
    [0048] [00048] Complex symbol demapper 440 performs processing inverted to the processing performed by complex symbol mapper 240 on the transmission apparatus at the input of symbol demapper / deinterleaver 430. Despite this processing, N dimensional rotated constellation symbols can be obtained.
    [0049] [00049] The rotated constellation demapper 450 performs demapping processing on the N dimensional rotated constellation symbols, and sends a decision result for each bit included in the N dimensional rotated constellation.
    [0050] [00050] Bit deinterleaver 460 performs processing inverted to the processing performed by bit interleaver 220 on the transmission apparatus at the entrance of the rotated constellation demapper 450.
    [0051] [00051] The FEC 470 decoder performs FEC decoding at the input of deinterleaver 470.
    [0052] [00052] Below, additional explanations of the rotated constellation demapper 450 are provided.
    [0053] (i) Primeiro desgirar a constelação, então extrair os bits para cada dimensão separadamente. (ii) Decodificar os bits de todas as dimensões em uma etapa. [00053] The rotated constellation demapper 450 can perform the demapping processing of N dimensional rotated constellation symbols in two ways (i) and (ii). (i) First remove the constellation, then extract the bits for each dimension separately. (ii) Decode the bits of all dimensions in one step.
    [0054] [00054] Although the first solution (a (i) above) is the simplest, its performance is less than ideal and even worse for rotated constellations than for non-rotated constellations. Due to its simplicity, this solution can be used in low-cost reception devices.
    [0055] [00055] Although the second solution (a (ii) above) is more complex, it offers a much better performance in terms of BER in a given SNR. In the following, the second solution will be described in more detail.
    [0056] [00056] As with the transmitting apparatus, a preferred embodiment of the receiving apparatus includes the FEC 470 decoder after the rotated constellation demapper 450, with the optional bit deinterleaver 460 between them, as illustrated in figure 4. More precisely, the rotated constellation demapper 450, which performs the demapping of the rotated constellation, receives dimensional N symbol vectors (y1, ..., yN) and the estimated fading coefficient vectors (h1, ..., hN), and extracts data of N * B bits (b1, ..., bN * B) of each symbol, as illustrated in figure 5.
    [0057] [00057] When FEC decoding is used, the demapping processing of the N dimensional rotated constellation symbols can no longer be performed by means of a hard decision, since the error correction performance would be less than ideal. Instead, "soft bits" should be used, either in the form of probabilities or in the form of log probability ratios (LLRs). The LLR representation is preferred since the probability multiplications can be conveniently expressed as sums. By definition, the LLR of a bk bit is illustrated in Mathematics 12 below. Mathematics 12
    [0058] [00058] Note that in Mathematics 12, P (bk = 0 | y) and P (bk = 1 | y) are the a priori probabilities that bk = 0 and bk = 1 are transmitted when the symbol vector y is received. According to known theory, the LLR of a bk bit of a constellation has the exact expression illustrated in Mathematics 13 below. Mathematics 13
    [0059] [00059] Note that in Mathematics 13, k is the bit index, y is the received symbol vector H is the diagonal matrix having associated (estimated) fading coefficients as elements on the main diagonal, s is a constellation point vector | | 2 is the square norm, and σ2 is the variation in noise.
    [0060] [00060] For an N dimensional constellation, the square norm represents the square Euclidean distance of the received symbol vector y to the faded constellation symbol vector Hs in N dimensional space. The square norm can be expressed by Mathematics 14 below. Mathematics 14
    [0061] [00061] Each bit bk divides the constellation into two partitions of equal size, Sk0 and Sk1, corresponding to the points for which bk is equal to 0 and 1, respectively. Examples are illustrated in figures 6a and 6b for a classic 16-QAM constellation with Gray coding. Figure 6a illustrates the constellation encoding and figure 6b illustrates the two partitions for each bit bk.
    [0062] [00062] The exact expression for LLR (Mathematics 13 above) is difficult to calculate due to exponentials, divisions and logarithms. In practice, the approximation illustrated in mathematics 15 below is performed, called max-log, which introduces negligible errors. Mathematics 15 ln (eα1 + eα2) ≈ max (α1, α2) → ln (e-α1 + e-α2) ≈ min (α1, α2)
    [0063] [00063] Using mathematics 15 above, mathematics 13 above results in a much simpler expression for LLR, which is illustrated in Mathematics 16 below. Mathematics 16
    [0064] [00064] For each symbol vector received y the distances to all constellation points 2B * N must be calculated, and the corresponding minimum for each partition is determined.
    [0065] [00065] Figure 7 illustrates a preferred hardware implementation of an LLR demapper (an example of the rotated constellation demapper 450 shown in figure 4) for a 16-QAM rotated constellation (N = 2, B = 2).
    [0066] [00066] The LLR demapper consists of a counter 710, a rotated constellation mapper 720, a square Euclidean distance calculator 730, minimizers 740-1 to 740-4 and adders 750-1 to 750-4.
    [0067] [00067] For each symbol vector received y counter 710 repeatedly generates all constellation points 24 = 16, and sends four bits b1, b2, b3, b4 indicating the constellation points to the rotated constellation mapper 720.
    [0068] [00068] The rotated constellation mapper 720 selects a 2D rotated constellation point from a lookup table by using counter values provided by counter 710 as indexes, and sends two constellation components s1 and s2 obtained through that selection to the 730 square Euclidean distance calculator.
    [0069] [00069] The square Euclidean distance calculator 730 calculates the square Euclidean distances (see figure 8).
    [0070] [00070] For each bit, the minimizers 740-1 to 740-4 maintain the corresponding minimum square Euclidean distances for two partitions (see figure 9). The two constellation partitions for each bit are simply indicated by the corresponding bit of counter 710.
    [0071] [00071] Each of the summers 750-1 to 750-4 subtracts the output of min 1 and min 0 being provided in each of the minimizers 740-1 to 740-4. After that, adders 750-1 to 750-4 send the subtraction results as L (b1) to L (b4), respectively.
    [0072] [00072] Figure 8 is a circuit diagram of a square Euclidean distance calculator that calculates a N dimensional square Euclidean distance. Note that the circuit structure of the square Euclidean calculator 730 has been modified from one illustrated in figure 8 in order to satisfy N = 2.
    [0073] [00073] The square Euclidean calculator consists of multipliers 810-1 to 810-N, additions 820-1 to 820-N, multipliers 830-1 to 830-N, and adder 840 and a multiplier 850.
    [0074] [00074] Multipliers 810-1 to 810-N multiply h1 to hN by S1 to sN, respectively. The additions 820-1 to 820-N subtract h1s1 from hNsN from y1 to yN, respectively. Multipliers 830-1 to 830-N multiply (y1-h1s1) a (yN - hNsN) by (y1-h1s1) a (yN-hNsN), respectively.
    [0075] [00075] The adder 840 adds the results of multipliers 830-1 to 830-N. Multiplier 850 multiplies the result of adder 840 by 1 / (2σ2)
    [0076] [00076] The result of the multiplier 850 is the N dimensional square Euclidean distance.
    [0077] [00077] Figure 9 is a circuit diagram of the minimizers 740-1 to 740-4, which each calculate the minimum square Euclidean distances for each bit. The subset of 1 bit (or partition) indicates the current position.
    [0078] [00078] Each of the minimizers 740-1 to 740-4 consists of a comparator 910, a selector 920, an inverter 930, flip-flops D 940-0 and 940-1, and a selector 950.
    [0079] [00079] The operations to be performed in the situation of figure 9 are described below when the subset value (the input value of counter 710) is equal to "0".
    [0080] [00080] Among the result of the flip-flop D 940-0 and the output of the flip-flop D 940-1, selector 950 selects and sends the first one.
    [0081] [00081] Comparator 910 compares din (A), which indicates the square Euclidean distance calculated by the square Euclidean distance calculator 730, with the output (B) of selector 950. In a case where B is less than A, the comparator 910 sends "0". In this case, between din and the output of selector 950, selector 920 selects and sends the last one based on "0" received from comparator 910. On the other hand, in a case where A is less than B, comparator 910 sends "1". In this case, between din and the output of selector 950, selector 920 selects and sends the first one based on "1" received from comparator 910. Note that in the case where A is equal to B, the same result will be obtained if selector 920 select din or selector 950 output. Accordingly, in this case, comparator 910 can send one of "0" and "1".
    [0082] [00082] The 930 inverter reverses the subset value "0". In this way, "1" is registered for the active flip-flop terminal D 940-0. As the D 940-0 flip-flop is activated, it locks the output of selector 920. Meanwhile, "0" is recorded in the active terminal of the D 940-1 flipflop. As the D 940-1 flip-flop is deactivated, it does not lock the 920 selector output.
    [0083] [00083] The following describes the operations to be performed in the situation of figure 9 when the subset value is equal to "1".
    [0084] [00084] Among the output of the D 940-0 flip-flop and the output of the D 940-1 flip-flop, the selector 950 selects and sends the last one.
    [0085] [00085] Comparator 910 compares din (A) with the output (B) of selector 950. In a case where B is less than A, comparator 910 sends "0". In this case, between din and the output of selector 950, selector 920 selects and sends the last one based on "0" received from comparator 910. On the other hand, in a case where A is less than B, comparator 910 sends "1". In this case, between din and the output of selector 950, selector 920 selects and sends the first one based on "1" received from comparator 910. Note that in this case where A is equal to B, the same result will be obtained if selector 920 selects din or selector 950 output. Accordingly, in this case, comparator 910 can send a "0" and "1".
    [0086] [00086] "1" is the input for the active flip-flop terminal D 940-1. As the flip-flop D 940-1 is activated, it locks the output of selector 920. Meanwhile, inverter 930 inverts the subset value "1". In this way, "0" is recorded in the active flipflop terminal D 940-0. As the D 940-0 flip-flop is deactivated, it does not lock the 920 selector output.
    [0087] [00087] A significant improvement in the performance of the receiver can be achieved by using interactive decoding. As illustrated in figure 10, the receiving apparatus configured to use such interactive decoding consists of a rotated constellation demapper 1010, a bit deinterleaver 1020, an FEC decoder 1030, and adder 1040, and a bit interleaver 1050. Here, the rotated constellation demapper 1010 and the FEC 1030 decoder are connected in a circuit.
    [0088] [00088] The 1010 rotated constellation demapper performs the demapping processing on N dimensional rotated constellation symbols, and sends L (see figure 11). Bit deinterleaver 1020 performs processing inverted to the processing performed by bit interleaver 220 on the transmission apparatus at the input of the rotated constellation demapper 1010. The FEC decoder 1030 performs FEC decoding at the input of the 1020 bit deinterleaver.
    [0089] [00089] Adder 1040 subtracts the input of the FEC decoder 1030 from the output of the FEC decoder 1030. The bit interleaver 1050 performs the same processing as the processing performed by bit interleaver 220 in the transmission apparatus at the output of adder 1040, and sends LE. LE, also referred to as extrinsic information, is fed back to the rotated constellation demapper 1010 in order to assist in the demapping processing of the N dimensional rotated constellation symbols. In this case, it is essential that FEC decoding produces soft bits, for example, in the form of LLRs.
    [0090] [00090] As is known in the literature, the formula for calculating the LLR for bit bk is provided by Mathematics 17 below.
    [0091] [00091] For example, x30 and x31 are illustrated in Mathematics 18 below. Mathematics 18
    [0092] [00092] Figure 11 illustrates an example of the structure of the rotated constellation demapper 1010 for interactive decoding. Note that the 1010 rotated constellation demapper for interactive decoding is similar to a rotated constellation demapper for non-interactive decoding. Below, the elements that are the same as those described above are given the same reference numbers, and a detailed description of them is omitted.
    [0093] [00093] The rotated constellation mapper 1010 consists of a counter 710, a rotated constellation mapper 720, a square Euclidean distance calculator 730, minimizers 740-1 to 740-4, summers 750-1 to 750-4, operators Logical ANDs 1110-1 to 1110-4, an adder 1120, adder 1130-1 to 1130-4 and adder 1140-1 and 1140-4.
    [0094] [00094] Logical AND operators 1110-1 to 1110-4 perform logical AND operations on the outputs of bit interleaver 1050, that is, LE (b1) to LE (b4), and the outputs of counter 710, that is, b1 to b4. Adder 1120 adds the outputs of logical AND operators 1110-1 to 1110-4. Each of the adder 1130-1 to 1130-4 subtracts, from the output of adder 1120, the output of a corresponding logical AND operator 1110-1 to 1110-4. Each of the adder 1140-1 to 1140-4 subtracts, from the output of the square Euclidean distance calculator 730, the output of a corresponding adder 1130-1 to 1130-4. Then, each of the adder 1140-1 and 1140-4 sends the value obtained by subtracting to din a corresponding minimizer 740-1 to 740-4. Citation List Non-Patent Literature
    [0095] [00095] NPL 1: K. Boulle and J.C. Belfiore. "Modulation Scheme Designed for the Rayleigh Fading Channel." presented in CISS 1992.
    [0096] [00096] NPL 2: B.D. Jelicic and S. Roy. "Design of Trellis Coded QAM for Flat Fading and AWGN Channels." IEEE Transactions on Vehicular Technology, Vol. 44, February 1995.
    [0097] [00097] NPL 3: Boutros and E. Viterbo, "Signal Space Diversity: A Power- and Bandwidth- Efficient Diversity Technique for the Rayleigh Fading Channel." IEEE Transactions on Information Theory, Vol. 44, July 1998.
    [0098] [00098] NPL 4: M. O. Damen, K. Abed-Meraim, and J.C. Belfiore, "Diagonal Algebraic Space-Time Block Codes." IEEE Transactions on Information Theory, Vol. 48. March 2002. Summary of the Invention Technical problem
    [0099] [00099] As described above, although a wide range of proposals have been made with respect to rotation matrices for rotating a constellation, the proposals that have been made so far do not provide any efficient method of generating a multidimensional rotated constellation (a matrix multidimensional rotation) for digital modulation with a high degree of modulation diversity in relation to the various constellation sizes.
    [0100] [000100] NPL 2 introduces an approach that makes use of a Givens rotation. The problem with this approach is that the number of parameters for generating an ideal multidimensional rotated constellation increases in the order of the square of the number of dimensions in the constellation.
    [0101] [000101] NPL 3 introduces two approaches. The first approach makes use of canonical inlay. According to this approach, the method of generating a multidimensional rotation matrix is determined only based on the number of dimensions, and does not have a parameter allowing the optimization of different constellation sizes. Therefore, the problem with this approach is that it does not allow for maximizing the effect of modulation diversity for various constellation sizes.
    [0102] [000102] The second approach introduced by NPL 3 generates a multidimensional rotation matrix having a larger number of dimensions by using the stacked expansion where the 2D and 3D rotation matrices are stacked. The problem with this approach is that the algebraic relationships between the stacked rotation matrices become more complicated as the number of dimensions increases, making optimization difficult.
    [0103] [000103] It is an objective of the present invention to provide an efficient method of generating a multidimensional rotated constellation (a multidimensional rotation matrix) for digital transmission with a high degree of modulation diversity with respect to various constellation sizes. It is also an object of the present invention to provide a transmission apparatus and a transmission method for transmitting data based on the multi-dimensional rotated constellation obtained by using the above method, and a receiving apparatus and a receiving method for receiving data with based on the multidimensional rotated constellation obtained by using the above method. Solution to the Problem
    [0104] [000104] A transmission apparatus of the present invention transmits a block of data through a plurality of transmission channels. The transmission apparatus comprises: a modulator operated to select one of a plurality of constellation points according to the data block to be transmitted, each one of the plurality of constellation points having a plurality of components; and a transmitter that operates to transmit each component of the selected constellation point through a different channel from among the plurality of transmission channels, where (i) the plurality of constellation points is defined by the positions within an N-dimensional space, the positions obtained by applying an orthogonal transformation to a subset of ZN which is an entire dimensional N lattice, (ii) N is a multiple of frame and (iii) the orthogonal transformation has a matrix representation of N by N with absolute values of all elements on a main diagonal equal to a first value, and with absolute values of all elements not on the main diagonal equal to a second nonzero value. Advantageous Effects of the Invention
    [0105] [000105] The above transmission device allows the efficient generation of a multidimensional rotated constellation (a multidimensional rotation matrix) for digital transmission with a high degree of modulation diversity in relation to various constellation sizes. Due to the multidimensional rotated constellation obtained by using the generated multidimensional rotation matrix, the transmission apparatus above also allows the data transmission to result in an effect of a high degree of modulation diversity. Brief Description of Drawings
    [0106] [000106] Figure 1a illustrates an illustrative 2D constellation and the fading effect.
    [0107] [000107] Figure 1b illustrates an illustrative 2D constellation that is obtained by rotating the constellation in figure 1a and the fading effect.
    [0108] [000108] Figure 2 illustrates a block diagram of a conventional transmission device.
    [0109] [000109] Figure 3 is a schematic drawing illustrating the mapping of constellation symbols to complex symbols.
    [0110] [000110] Figure 4 is a block diagram of a conventional receiver.
    [0111] [000111] Figure 5 is an illustration of the inputs to and from a rotated constellation demapper.
    [0112] [000112] Figure 6a illustrates an example of a conventional 16-QAM constellation with Gray encoding.
    [0113] [000113] Figure 6b illustrates the two partitions for each bit of the constellation in figure 6a.
    [0114] [000114] Figure 7 illustrates an illustrative hardware implementation of an LLR demapper for a rotated 16-QAM constellation.
    [0115] [000115] Figure 8 illustrates an illustrative hardware implementation for a square Euclidean distance calculator that calculates the N dimensional square Euclidean distance.
    [0116] [000116] Figure 9 illustrates an illustrative hardware implementation for a minimizer that calculates the minimum square Euclidean distances.
    [0117] [000117] Figure 10 illustrates a block diagram of a circuit that performs interactive decoding.
    [0118] [000118] Figure 11 illustrates an illustrative hardware implementation of the rotated constellation demapper for interactive decoding.
    [0119] [000119] Figure 12 illustrates a block diagram of a transmission apparatus according to an embodiment of the present invention.
    [0120] [000120] Figure 13 illustrates a block diagram of a receiving apparatus according to an embodiment of the present invention.
    [0121] [000121] Figure 14 is a block diagram of the rotated constellation demapper illustrated in figure 13. Description of Modalities
    [0122] [000122] The present invention provides a first transmission apparatus for transmitting a block of data through a plurality of transmission channels, the first transmission apparatus comprising: a modulator which operates to select one from a plurality of constellation points according to the data block to be transmitted, each one of the plurality of constellation points having a plurality of components; and a transmitter that operates to transmit each component of the selected constellation point through a different channel from among the plurality of transmission channels, where (i) the plurality of constellation points is defined by their positions within an N-dimensional space, the positions being obtained by applying an orthogonal transformation to a subset of ZN which is an entire N dimensional trellis, (ii) N is a multiple of four and (iii) the orthogonal transformation has a matrix representation of N by N with absolute values of all elements on a main diagonal equal to a first value, and with absolute values of all elements not on the main diagonal equal to a second nonzero value.
    [0123] [000123] The present invention also provides a first transmission method for transmitting a block of data through a plurality of transmission channels, the first transmission method comprising the steps of: selecting one from a plurality of constellation points according to the data block to be transmitted, each one of the plurality of constellation points having a plurality of components: and transmitting each component of the selected constellation point through a different channel among the plurality of transmission channels, where (i) the plurality of constellation points are defined by their positions within an N dimensional space, the positions being obtained by applying an orthogonal transformation to a subset of ZN which is an entire dimensional N lattice, (ii) N is a multiple of four, and (iii) the orthogonal transformation has a matrix representation of N by N with absolute values of all elements on a main diagonal equal to a first value , and with absolute values of all elements not on the main diagonal equal to a second nonzero value.
    [0124] [000124] The above transmission apparatus and the transmission method allow for the efficient generation of a multi-dimensional rotated constellation (a multi-dimensional rotation matrix) for digital transmission with a high degree of modulation diversity with respect to various constellation sizes. Due to the multidimensional rotated constellation obtained by using the generated multidimensional rotation matrix, the transmission apparatus and the transmission method above also allow the data transmission to result in an effect of a high degree of modulation diversity.
    [0125] [000125] The present invention also provides a second transmission device and a second transmission method, which are the first transmission device and the second transmission device, respectively, where instead of the representation of matrix N by N, the orthogonal transformation has a matrix representation obtained by exchanging rows and / or columns in the matrix representation of N by N.
    [0126] [000126] The above structure produces the same effect as the effect produced by the representation of the matrix of N by N with absolute values of all elements on the main diagonal equal to a first value, and with the absolute values of all elements not on the diagonal principal equal to a second nonzero value.
    [0127] [000127] The present invention also provides a third transmission apparatus, which is the first transmission apparatus further comprising a mapper which operates to map each component of the selected constellation point to a corresponding channel among the plurality of transmission channels through which the component must be transmitted, so that the fading of each of the plurality of transmission channels is not correlated with the fading of any other among the plurality of transmission channels.
    [0128] [000128] The present invention also provides a third method of transmission, which is the first method of transmission further comprising the step of mapping each component of the selected constellation point to a corresponding channel among the plurality of transmission channels through which the component must be transmitted, so that the fading of each of the plurality of transmission channels is not correlated with the fading of any of the plurality of transmission channels.
    [0129] [000129] The above structure can optimize the transmission performance, even in the presence of fading.
    [0130] [000130] The present invention also provides a fourth transmission device, which is the first transmission device where the transmitter is adapted to transmit each component of the selected constellation point through a different partition among a plurality of time, frequency, transmitting antennas, or combinations thereof.
    [0131] [000131] The present invention also provides a fifth transmission apparatus and a fourth transmission method, which are the first transmission apparatus and the first transmission method, respectively, where the plurality of transmission channels comprises a plurality of different carriers in an orthogonal frequency division multiplexing scheme.
    [0132] [000132] The present invention also provides a sixth transmission apparatus and a fifth transmission method, which are the first transmission apparatus and the first transmission method, respectively, where the plurality of transmission channels comprises a plurality of different symbols in an orthogonal frequency division multiplexing scheme.
    [0133] [000133] The present invention also provides a first receiving apparatus for receiving a block of data through a plurality of transmission channels, the first receiving apparatus comprising: a receiver operating to receive a plurality of component signals through the plurality transmission channels; and a demodulator that operates to select one of a plurality of constellation points according to the plurality of component signals received, where (i) the plurality of constellation points is defined by their positions within an N dimensional space, the positions being obtained by applying an orthogonal transformation to a subset of ZN which is an entire dimensional N lattice, (ii) N is a multiple of four, and (iii) the orthogonal transformation has a matrix representation of N by N with absolute values of all elements on a main diagonal equal to a first value , and with absolute values of all non-main diagonal elements equal to a second nonzero value
    [0134] [000134] The present invention also provides a first receiving method for receiving a block of data through a plurality of transmission channels, the first receiving method comprising the steps of: receiving a plurality of component signals through the plurality of channels transmission; and selecting one from the plurality of constellation points according to the plurality of component signals received, where (i) the plurality of constellation points is defined by their positions within an N-dimensional space, the positions being obtained by applying an orthogonal transformation to a subset of ZN which is an entire dimensional N lattice, (ii) N is a multiple of four, and (iii) the orthogonal transformation has a matrix representation of N by N with absolute values of all elements on a main diagonal equal to a first value and with the absolute values of all elements not on the main diagonal equal to a second nonzero value.
    [0135] [000135] The reception apparatus and the reception method above allow the efficient generation of a multidimensional rotated constellation (a multidimensional rotation matrix) for digital transmission with a high degree of modulation diversity in relation to various constellation sizes. Due to the multidimensional rotated constellation obtained by using the multidimensional rotation matrix, the receiving apparatus and the receiving method above also allow the reception of data to result in an effect of a high degree of modulation diversity.
    [0136] [000136] The present invention also provides a second receiving device and a second receiving method, which are the first receiving device and the first receiving method, respectively, where instead of the representation of matrix N by N, the orthogonal transformation has a matrix representation obtained by exchanging rows and / or columns in the matrix representation N by N.
    [0137] [000137] The above structure produces the same effect as the effect produced by the representation of the matrix of N by N with absolute values of all elements on the main diagonal equal to a first value, and with the absolute values of all elements not on diagonal principal equal to a second nonzero value.
    [0138] [000138] The present invention also provides a third receiving device and a third receiving method which are the first receiving device and the first receiving method, respectively, where the plurality of transmission channels comprises a plurality of different carriers in one orthogonal frequency division multiplexing scheme.
    [0139] [000139] The present invention also provides a fourth receiving device and a fourth receiving method, which are the first receiving device and the first receiving method, respectively, where the plurality of transmission channels comprises a plurality of different symbols in an orthogonal frequency division multiplexing scheme.
    [0140] [000140] The present invention also provides a first generation method to generate a multidimensional constellation for a digital modulation scheme in a data communication system, the first generation method comprising the steps of: receiving a plurality of vectors from a space multidimensional vector; and obtain constellation points of the vectors of a multidimensional vector space by applying an orthogonal transformation to the plurality of vectors received, where (i) the orthogonal transformation is adapted to increase a minimum number of different values in components s of any two points of distinct multidimensional constellation with respect to a minimum number of different values in components of any two distinct vectors received, and (ii) the orthogonal transformation has a matrix representation of N by N, N being a multiple of four, with absolute values of all the elements on a main diagonal equal to a first value, and with the absolute values of all elements not on the main diagonal equal to a second non-zero value.
    [0141] [000141] The generation method above allows efficient generation of a multidimensional rotated constellation (a multidimensional rotation matrix) for digital transmission with a high degree of modulation diversity in relation to the various constellation sizes.
    [0142] [000142] The present invention also provides a second generation method to generate a multidimensional constellation, where instead of the representation of matrix N by N, the orthogonal transformation has a representation of matrix obtained by the exchange of rows and / or columns in the representation of matrix of N by N.
    [0143] [000143] The above structure produces the same effect as the effect produced by the representation of matrix N by N with absolute values of all elements on the main diagonal equal to a first value, and with absolute values of all elements not on the main diagonal equal to a second nonzero value.
    [0144] [000144] The present invention also provides a third generation method for generating a multidimensional constellation, the third generation method being the first generation method further comprising the steps of: selecting a rotation factor r as a real number between 0 and 1; calculation of the first value, a, by evaluating the expression
    [0145] [000145] With the above structure, the orthogonal transformation can be readily determined.
    [0146] [000146] The present invention also provides a fourth generation method for generating a multidimensional constellation, the fourth generation method being the third generation method where the selected rotation factor r maximizes the minimum number of different values in the components of any two points of different multidimensional constellations.
    [0147] [000147] The above structure makes it possible to achieve a high degree of modulation diversity and increased robustness in the presence of fading, while preserving spectral efficiency.
    [0148] [000148] The present invention also provides a fifth generation method for generating a multidimensional constellation, the fifth generation method being the first generation method where the plurality of vectors represent a subset of ZN which is an entire N dimensional truss.
    [0149] [000149] The above structure is useful in a direct numerical implementation.
    [0150] [000150] The following describes an embodiment of the present invention with reference to the drawings.
    [0151] [000151] First, a description is now provided for multidimensional rotation matrices.
    [0152] (i) Cada saída deve ter uma entrada dominante. (ii) As entradas restantes devem ter pesos iguais. [000152] Multidimensional rotation matrices have a single independent parameter and a structure that is as regular as possible. The parameter can be configured to minimize the likelihood of error for various constellation sizes. Specifically, the following two conditions (i) and (ii) are imposed on the multidimensional rotation matrix used to obtain a multidimensional rotated constellation. (i) Each exit must have a dominant entry. (ii) The remaining entries must be of equal weight.
    [0153] [000153] The conditions above (i) and (ii) are fulfilled if the multidimensional rotation matrix has the form illustrated in Mathematics 19 below (for N = 4), or more generally, as illustrated in Mathematics 20 to follow. Note that the multidimensional rotation matrix illustrated in Mathematics 20 is a matrix of N by N. Mathematics 19
    [0154] [000154] Here, a and b denote real parameters, with each sign value si, already satisfying si, j ∊ {-1, +1}
    [0155] [000155] Note that the values of parameters a and b that fulfill the conditions above (i) and (ii) satisfy an expression of relation to> b> 0.
    [0156] [000156] Obviously, the same advantages can be achieved by exchanging rows and / or columns of the multidimensional rotation matrix in mathematics 20 above. Therefore, the matrix illustrated in Mathematics 20 can be used as the multidimensional rotation matrix. Alternatively, it is also possible to use a matrix obtained by exchanging rows and / or columns of the matrix illustrated in Mathematics 20 as the multidimensional rotation matrix. The matrix illustrated in mathematics 20 and the matrix obtained by exchanging rows and / or columns of the matrix illustrated in mathematics 20 have the following characteristics: (i) each row contains an element having a real parameter a; (ii) each column contains an element having a real parameter a; and (iii) the rest of the elements in each row / column having a real parameter b.
    [0157] [000157] The normalization of the multidimensional rotation matrix illustrated in mathematics 20 above is described below. Note that similar normalization can be performed on a matrix (a multidimensional rotation matrix) obtained by exchanging the rows and / or columns of the matrix illustrated in mathematics 20.
    [0158] [000158] The normalization condition establishes the relationship illustrated in Mathematics 21 below between parameters a and b. Mathematics 21 a2 + (n-1) b2 = 1
    [0159] [000159] Therefore, the multidimensional rotation matrix has only one independent parameter. In mathematics 22 below, a "rotation factor" r between 0 and 1 is defined. Mathematics 22 Without rotation: r = 0 -> b = 0 a = 1 Maximum rotation: r = 1 -> b = a = √1 / N
    [0160] [000160] Therefore, parameters a and b can be expressed in terms of "rotation factor" r as illustrated in Mathematics 23 below. Mathematics 23
    [0161] [000161] The advantage of using the "rotation factor" r is that the range is always 0 to 1 regardless of the number of dimensions. The ideal value for the "rotation factor" r depends on the size of the constellation, that is, the number of dimensions N and the number of bits B per dimension for square / cubic constellations. Note that the value of r satisfying the conditions above (i) and (ii) is greater than 0 and less than 1.
    [0162] [000162] The multidimensional rotation matrix for rotating a multidimensional constellation can be normalized or not.
    [0163] [000163] The only open problem is that the signal matrix values s should take over. The signal matrix s is defined by mathematics 24 below. Mathematics 24
    [0164] [000164] A necessary condition, which is not sufficient however, is that the signal matrix s it must be orthogonal, up to a scaling factor. Such matrices are known in the literature as Hadamard matrices. Since a and b in the multidimensional rotation matrix R are different, the additional condition illustrated in Mathematics 25 below must be imposed. Mathematics 25 Si, iSi, j = -Sj, iSj, j for all i ≠ j
    [0165] [000165] This condition guarantees that any product a * b cancels with the corresponding product b * a.
    [0166] [000166] If all elements on the main diagonal have the same sign, and each pair of elements that are symmetrical with respect to the main diagonal have opposite signs, this condition is met. Examples of such signal matrices particularly preferred for cases 4D and 8D are illustrated in Mathematics 26 and Mathematics 27 below, respectively. Mathematics 26
    [0167] [000167] It should be noted that Hadamard matrices are only possible for sizes that are multiples of four. Therefore, multidimensional rotation matrices exist only for numbers of dimensions of a constellation according to the present invention, it is preferably a multiple of four (for example, 4, 8, 12 and 16).
    [0168] [000168] Since the signal matrix s was fixed, the resulting multidimensional rotation matrix R can be optimized for a given constellation size, that is, the number of bits or constellation points per dimension, by performing the following steps: selecting the "rotation factor" r accordingly; and calculation of parameters a and b by replacing the "rotation factor" selected r in Mathematics 23 above. For this purpose, any suitable optimization algorithm can be employed. As an optimization target, the minimum number of different values in the components of any two distinct multidimensional rotated constellation points can be employed. Other optimization targets can be used as well. According to a preferred embodiment of the present invention, a cost function is defined and takes the absolute minimum differences between the corresponding components of any two multidimensional rotated constellation points into consideration. An example of such a cost function calculates the minimum over all absolute differences N between the corresponding components of two multidimensional rotated constellation points and adds three minimum values, or their squares across all pairs of multidimensional rotated constellation points.
    [0169] [000169] The multidimensional rotated constellation can already be useful if the minimum number of different values in the components of any two different multidimensional rotated constellation points is greater than those belonging to the multidimensional un rotated constellation. In addition, the multidimensional rotated constellation may already be useful if the minimum absolute difference of two corresponding components from any two distinct multidimensional rotated constellation points is greater than those belonging to the multidimensional unrotated constellation.
    [0170] [000170] In a preferred embodiment of the present invention, the entire transmission process including the transmission channel and the decoder is simulated in order to determine the bit error rate. The "rotation factor" r can then be adapted to minimize the determined bit error rate.
    [0171] [000171] Thus, the present invention allows the generation of a rotated multidimensional constellation that can be used to modulate and transmit data through a plurality of channels or fading partitions with ideal spectral efficiency. For this purpose, a conventional hypercubic constellation with the desired number of dimensions N and the desired number of bits can dimension (that is, the number of constellation points per direction) is configured, for example, by selecting an appropriate subset of ZN which is the entire N dimensional truss. On here, ZN it is the set of all points in the N dimensional space having whole coordinates. This hyper cubic constellation may, for example, be a generalization of a regular regular QAM constellation for N dimensions. However, other initial constellations can be used, such as generalizations of the circular constellation for N dimensions, and so on.
    [0172] [000172] Once the initial constellation is fixed, it can be rotated by applying the multidimensional rotation matrix defined above R for each of the initial constellation points in order to obtain a rotated set of constellation points, that is, a multidimensional rotated constellation. The multi-dimensional rotated constellation may be more favorable than the initial constellation in terms of the degree of modulation diversity provided, depending on the particular choice of "rotation factor" r. The "rotation factor" with which the rotated constellation can vary, as described above, in order to obtain a constellation that provides maximum modulation diversity, or at least a determined minimum degree of modulation diversity, as required by the specific application. .
    [0173] [000173] The present invention also provides a method and apparatus for the efficient transmission and reception of data through a plurality of channels or fading partitions based on a modulation scheme that employs a multidimensional rotated constellation as obtained by the method described above . The inventive method or apparatus can perform the method described above in order to obtain the desired multidimensional rotated constellation, or use a set of pre-stored and predefined constellation points of the multidimensional rotated constellation that have been calculated using the method described above. In the latter case, the inventive method or apparatus can access a storage device, in which information indicating the positions of at least some of the constellation points is stored.
    [0174] [000174] Another aspect of the present invention relates to the separation and mapping of the N dimensions of the N dimensional rotated constellation so that they are subjected to independent fading during transmission. This is a key aspect needed to achieve the expected diversity performance.
    [0175] [000175] Generally, this can be achieved by transmitting each of the N components of a constellation point of a rotated N-dimensional constellation through a different channel among the plurality of transmission channels, as long as the fading of each of these channels of transmission is not correlated with the fading of any other of the transmission channels. Here, the phrase "a different channel among the plurality of transmission channels" can refer to a different time partition, frequency, transmitting antenna or combination among the plurality of time partitions, frequencies, transmitting antennas, or combinations thereof. In the context of orthogonal frequency division multiplexing (OFDM), the phrase "a different channel among the plurality of channels" can in particular refer to a different one among a plurality of active carriers, OFDM symbols, or combinations thereof. In the context of a single carrier system, the phrase "a different channel among the plurality of transmission channels" can, in particular, refer to one among a plurality of symbols or time partitions.
    [0176] [000176] Additional signal processing is possible before transmission. The critical aspect is that the fading suffered by each of the N dimensions must be different from, or ideally not correlated with, the fading suffered by another of the N dimensions.
    [0177] [000177] The spreading of the N dimensions across different time partitions, frequencies and transmitting antennas can be achieved, for example, through the appropriate interleaving and mapping.
    [0178] [000178] Another aspect of the present invention relates to the mapping of n real dimensions of the rotated constellation N dimensional into complex symbols for transmission. Since the fading of the phase component, and the quadrature component of a given channel is typically identical, a complex symbol may not be made from two different components from the same constellation point. Instead, the N components of a constellation point must be mapped to different complex symbols in order to guarantee the desired diversity.
    [0179] [000179] The complex symbols generated in this way are then spread in a conventional way through the available time partitions, frequencies and / or antennas, for example, through interleaving and mapping, so that the fading suffered by each of the N dimensions does not be correlated with the fading suffered by any of the other N dimensions.
    [0180] [000180] The following is an illustrative flow of a method for generating a multidimensional constellation for a digital modulation scheme in data transmission. This flow is achieved by, for example, a computer system. Each of the following steps is performed by a central processing unit (CPU).
    [0181] [000181] Step 1. A plurality of vectors from an N dimensional vector space is received. Note, for example, the plurality of vectors received represents a set of ZN which is an entire N dimensional truss.
    [0182] [000182] Step 2 The signal values si, j of the signal matrix illustrated in Mathematics 24 above are determined, so that the N dimensional rotation matrix R illustrated in mathematics 20 above is orthogonal. Step 3
    [0183] [000183] A "rotation factor" r is selected as a real number between 0 and 1. It should be noted that the "rotation factor" r, for example, is selected in order to maximize the minimum number of different values in components of any two distinct multidimensional constellation points. However, the present invention is not limited to that. Alternatively, the "rotation factor" r can be selected so as to increase a minimum number of different values in components of any two distinct N dimensional rotated constellation points with respect to a minimum number of different values in components of any two distinct vectors received in Step 1. Step 4
    [0184] [000184] The values of parameters a and b are calculated by replacing the value of "rotation factor" r, which was selected in Step 3, in mathematics 23 above. Step 5
    [0185] [000185] The N dimensional rotation matrix R is determined from Mathematics 20 above by using (i) a signal matrix s having the signal values si, already determined in Step 2, and (ii) the parameter values a and b calculated in Step 4. Step 6
    [0186] [000186] A constellation point of the N dimensional rotated constellation is obtained by applying the N dimensional rotation matrix R determined in Step 5 for the plurality of vectors of the multidimensional vector space, which were received in Step 1.
    [0187] [000187] Figure 12 is a block diagram of a transmission apparatus according to one embodiment of the present invention, which is similar to that illustrated in figure 2. The elements that are the same as those described above receive the same numerical references, and a detailed explanation of them is omitted.
    [0188] [000188] The transmission apparatus of figure 12 differs from that of figure 2 in that the rotated constellation demapper 230 is replaced by a rotated constellation demapper 1230. The rotated constellation demapper 1230 performs the processing based on a rotated constellation N dimensional has a plurality of constellation points defined by their positions within an N dimensional space, the positions being obtained by the application of the N dimensional rotation matrix illustrated in Mathematics 20 above, or an N dimensional rotation matrix obtained by the exchange of rows and / or columns of the N dimensional rotation matrix illustrated in Mathematics 20 above, for a subset of ZN which is the entire N dimensional truss. To be more specific, this processing serves to map the output of bit interleaver 220 to the rotated constellation.
    [0189] [000189] Figure 13 is a block diagram of a receiving apparatus according to one embodiment of the present invention, which is similar to that illustrated in Figure 4. The elements that are the same as those described above receive the same numerical references and a detailed explanation will be omitted.
    [0190] [000190] The receiving apparatus of figure 13 differs from that of figure 4 in that the rotated constellation demapper 450 is replaced by a rotated constellation demapper 1350. The rotated constellation demapper 1350 performs the processing based on a rotated constellation N dimension that has a plurality of constellation points defined by their positions within an N dimensional space, the positions being obtained by the application of the N dimensional rotation matrix illustrated in Mathematics 20 above, or an N dimensional rotation matrix obtained by the exchange of rows and / or columns of the N dimensional rotation matrix illustrated in mathematics 20 above, to a subset of ZN which is an entire N dimensional truss.
    [0191] [000191] Figure 14 illustrates an illustrative hardware implementation for the 1350 rotated constellation demapper of figure 13 for a 16-QAM rotated constellation (N = 2, B = 2). The rotated constellation mapper 1350 of figure 13 includes a rotated constellation mapper 1420, instead of the rotated constellation map 720 shown in figure 7. The rotated constellation mapper 1420 maps the outputs b1 to b4 of counter 710 to a rotated constellation N dimension that has a plurality of constellation points defined by their positions within an N dimensional space, the positions being obtained by the application of the N dimensional rotation matrix illustrated in Mathematics 20 above, or an N dimensional rotation matrix obtained by the exchange of rows and / or columns of the N dimensional rotation matrix illustrated in Mathematics 20 above to a subset of ZN which is the entire N dimensional truss. Then, the rotated constellation mapper 1420 sends the resulting constellation components s1 to s4 to the square Euclidean distance calculator 730.
    [0192] [000192] It should be noted that the structures of the transmitting and receiving apparatus are not limited to those described above. For example, the receiving apparatus may have one of the structures illustrated in figures 10 and 12. In this case, the rotated constellation demapper 1010 or 720 performs processing based on an N dimensional rotated constellation that has a plurality of defined constellation points. by their positions within an N dimensional space, the positions being obtained by applying the N dimensional rotation matrix illustrated in Mathematics 20 above, or an N dimensional rotation matrix obtained by swapping rows and / or columns of the N rotation matrix dimensional illustrated in Mathematics 20 above to a subset of ZN which is the entire N dimensional truss.
    [0193] [000193] The present invention relates to the communication of digital data and provides an efficient method for the generation of multidimensional constellations for modulation of digital data with a high degree of modulation diversity, a method for the transmission and reception of data based on such constellations and a corresponding apparatus. This is achieved by considering only multidimensional rotation matrices with all elements on the diagonal having the same first absolute value and all other elements having the same second absolute value. In this way, multidimensional rotation matrices can be generated having a single independent parameter and a structure that is as regular as possible. The independent parameter can be configured to minimize the probability of error for various constellation sizes. Industrial Applicability
    [0194] [000194] The present invention is applicable to a communication device that performs modulation and demodulation by using a constellation. List of reference signs 210 FEC encoder 220 bit interleaver 1230 rotated constellation mapper 240 complex symbol mapper 250 symbol interleaver / mapper 260-1 to 260-M modulating current 270-1 to 270-M transmitting antenna 410-1 to 410-M receiving antenna 420-1 to 420-M demodulation current 430 symbol demapper / deinterleaver 440 complex symbol demapper 1350 rotated constellation demapper 460 bit deinterleaver 470 FEC decoder
    权利要求:
    Claims (5)
    [0001]
    Transmission apparatus for transmitting a block of data through a plurality of transmission channels, the transmission apparatus characterized by comprising: a modulator (260-1, ..., 260-M) that operates to select one of a plurality of constellation points according to the data block to be transmitted, each one of the plurality of constellation points having a plurality of components; and a transmitter that operates to transmit each component of the selected constellation point through a different channel from among the plurality of transmission channels; on what the plurality of constellation points are defined by their positions within the N dimensional space, the positions being obtained by applying an orthogonal transformation to a subset of ZN which is an entire N dimensional trellis, N is a multiple of four, and the orthogonal transformation has one of (i) a matrix representation of N by N with absolute values of all elements on a main diagonal equal to a first value, and with absolute values of all elements not on the main diagonal equal to one second nonzero value, and (ii) a matrix representation obtained by exchanging rows and / or columns in the matrix representation of N by N.
    [0002]
    Receiving apparatus for receiving a block of data through a plurality of transmission channels, the receiving apparatus characterized by comprising: a receiver that operates to receive a plurality of component signals through the plurality of transmission channels; and a demodulator (420-1, ..., 420-M) that operates to select one of a plurality of constellation points according to the plurality of component signals received in which the plurality of constellation points is defined by their positions within an N dimensional space, the positions being obtained by applying an orthogonal transformation to a subset of ZN which is an entire N dimensional trellis; N is a multiple of four; and the orthogonal transformation has one of (i) a matrix representation of N by N with absolute values of all elements on a main diagonal equal to a first value and with absolute values of all elements not on the main diagonal equal to a second value nonzero, and (ii) a matrix representation obtained by exchanging rows and / or columns in the matrix representation of N by N.
    [0003]
    Transmission method for transmitting a block of data through a plurality of transmission channels, the transmission method characterized by comprising the steps of: selecting one from a plurality of constellation points according to the data block to be transmitted, each from the plurality of constellation points having a plurality of components, and transmit each component of the selected constellation point through a different channel within the plurality of transmission channels, where the plurality of constellation points is defined by their positions within an N dimensional space, the positions being obtained by applying a transformation orthogonal to a subset of ZN which is an entire N dimensional trellis, N is a multiple of four, and the orthogonal transformation has one of (i) a representation of matrix N by N with absolute values of all elements on a main diagonal equal to a first value and with absolute values of all elements not on the main diagonal equal to a different second value zero, and (ii) a matrix representation obtained by exchanging rows and / or columns in the matrix representation of N by N.
    [0004]
    Reception method for receiving a block of data through a plurality of transmission channels, the reception method characterized by comprising the steps of: receiving a plurality of component signals through the plurality of transmission channels; and select one from a plurality of constellation points according to the plurality of component signals received, where the plurality of constellation points are defined by their positions within an N dimensional space, the positions being obtained by applying an orthogonal transformation to a subset of ZN which is an entire N dimensional trellis, N is a multiple of four, and the orthogonal transformation has one of (i) a representation of matrix N by N with absolute values of all elements on a main diagonal equal to a first value, and with absolute values of all elements not on the main diagonal equal to a second non-zero value, and (ii) a matrix representation obtained by exchanging rows and / or columns in the matrix representation of N by N.
    [0005]
    Generation method to generate a multidimensional constellation for a digital modulation scheme in a data communication system, the generation method characterized by understanding the steps of: receiving a plurality of vectors from a multidimensional vector space; and obtain the constellation points of the multidimensional constellation by applying an orthogonal transformation to the plurality of vectors received, where the orthogonal transformation is adapted to increase a minimum number of different values in components of any two different multidimensional constellation points with respect to a minimum number of different values in components of any two distinct vectors received, and the orthogonal transformation has one of (i) a matrix representation of N by N, N being a multiple of four, with absolute values of all elements on a main diagonal equal to a first value, and with the absolute values of all elements not on the main diagonal equal to a second nonzero value, and (ii) a matrix representation obtained by exchanging rows and / or columns in the matrix representation of N by N.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US5832044A|1996-09-27|1998-11-03|Elvino S. Sousa|Transmitter antenna diversity and fading-resistant modulation for wireless communication systems|
    US6449246B1|1999-09-15|2002-09-10|Telcordia Technologies, Inc.|Multicarrier personal access communication system|
    JP3696013B2|1999-11-30|2005-09-14|株式会社豊田中央研究所|Diversity receiving system for multicarrier modulation and diversity receiving apparatus for multicarrier modulation|
    US6418170B1|2000-02-07|2002-07-09|Motorola, Inc.|Method and apparatus for achieving 180° phase invariant transmission in a PCM modem system|
    JP2004520727A|2000-04-18|2004-07-08|リンクエアコミュニケーションズ，インコーポレイテッド|Orthogonal transform method of spread spectrum multiple access code|
    WO2003019791A2|2001-08-23|2003-03-06|Nortel Networks Limited|System and method for reducing the peak power in multi-carrier modulation|
    US7095812B2|2002-06-24|2006-08-22|Agere Systems Inc.|Reduced complexity receiver for space-time- bit-interleaved coded modulation|
    JP4353774B2|2002-12-04|2009-10-28|パナソニック株式会社|Data transmission method and data reception method, and transmission apparatus and reception apparatus using them|
    JP4052388B2|2003-03-31|2008-02-27|アイコム株式会社|Transmission device, reception device, transmission method, reception method, and program|
    EP1616424A4|2003-04-21|2009-12-02|Rgb Networks Inc|Wideband multi-channel quadrature amplitude modulation of cable television signals|
    EP1635495A1|2003-07-14|2006-03-15|Matsushita Electric Industrial Co., Ltd.|Multi-carrier transmitter apparatus, multi-carrier receiver apparatus, and multi-carrier communication method|
    US7545873B2|2003-09-30|2009-06-09|Panasonic Corporation|Radio transmission apparatus, radio reception apparatus and radio transmission method|
    KR20050041346A|2003-10-30|2005-05-04|엘지전자 주식회사|A method of selecting optimistic mcs level mimo|
    KR100757963B1|2003-12-24|2007-09-11|삼성전자주식회사|A Method And Apparatus For CODING|
    CN101263679A|2005-08-12|2008-09-10|诺基亚公司|Method, system, apparatus and computer program product for placing pilots in a multicarrier MIMO system|
    JP4611864B2|2005-10-28|2011-01-12|Ｋｄｄｉ株式会社|Transmission method|
    JP4684852B2|2005-11-02|2011-05-18|Ｋｄｄｉ株式会社|Code spreading method and code spreading apparatus|
    EP1985082B1|2005-12-12|2015-04-22|Koninklijke Philips N.V.|Integer spreading rotation matrices for qam constellations and its application to decode-remodulate-forward cooperative communication strategy|
    CN100518165C|2006-12-07|2009-07-22|杭州电子科技大学|Hard-decision method fitted for implementation of multilevel quadrature amplitude modulation|
    CN101295989B|2007-04-29|2011-12-07|中兴通讯股份有限公司|Space-time and space-frequency block encoding method for orthogonal frequency division multiplexing|
    US8867662B2|2008-03-31|2014-10-21|Qualcomm Incorporated|Multidimensional constellations for coded transmission|
    CN101404642A|2008-11-14|2009-04-08|南京航空航天大学|Soft demodulation method for 32 ary quadrature amplitude modulation|
    EP2288048A1|2009-08-21|2011-02-23|Panasonic Corporation|Rotated multi-dimensional constellations for improved diversity in fading channels|
    CN102263580A|2010-05-24|2011-11-30|华为技术有限公司|Broadcast signal transmitting method and device|JPS61128274A|1984-11-27|1986-06-16|Konishiroku Photo Ind Co Ltd|Fixing device|
    JP3592809B2|1995-09-13|2004-11-24|東レ・ダウコーニング・シリコーン株式会社|Silicone rubber composition for fluororesin-coated fixing roll and fluororesin-coated fixing roll|
    JP4064026B2|1999-12-22|2008-03-19|東レ・ダウコーニング株式会社|Liquid silicone rubber composition for fixing roll and fixing roll coated with fluororesin|
    EP2288048A1|2009-08-21|2011-02-23|Panasonic Corporation|Rotated multi-dimensional constellations for improved diversity in fading channels|
    KR20120110376A|2011-03-29|2012-10-10|삼성전자주식회사|Method of demodulating data and method of data communication|
    EP2523412B1|2011-05-11|2018-09-26|Samsung Electronics Co., Ltd.|Apparatus and method for soft demapping|
    KR20120132994A|2011-05-30|2012-12-10|삼성전자주식회사|Apparatus and method for soft demmaping|
    EP2566119A1|2011-08-29|2013-03-06|Panasonic Corporation|Generalized rotated constellations for time-frequency slicing|
    EP2779560B1|2011-11-10|2017-09-13|Sun Patent Trust|Transmitting method, receiving method, transmitter and receiver|
    EP2592773A1|2011-11-10|2013-05-15|Panasonic Corporation|Improved diversity fo rotated constellations with time-frequency slicing|
    EP2592772A1|2011-11-10|2013-05-15|Panasonic Corporation|Improved time diversity for rotated constellations|
    EP2618532A1|2012-01-19|2013-07-24|Panasonic Corporation|Improved Component Interleaving for Rotated Constellations|
    KR102024796B1|2012-04-13|2019-11-04|한국전자통신연구원|Apparatus and Method of Transmission of Hierarchically Modulated Signal|
    EP2690813A1|2012-07-27|2014-01-29|Panasonic Corporation|Transparent component interleaving for rotated constellations|
    EP2879297B1|2012-07-27|2019-03-13|Sun Patent Trust|Transmission method, transmitter, reception method, and receiver|
    US9325427B1|2012-10-31|2016-04-26|Ciena Corporation|Maximum likelihood decoding|
    US9106470B2|2012-12-03|2015-08-11|Qualcomm Incorporated|Enhanced decoding and demapping method and apparatus for QAM data signals|
    US9385905B2|2013-03-04|2016-07-05|Intel Corporation|Block-based time-frequency interleaving and de-interleaving|
    GB201312243D0|2013-07-08|2013-08-21|Samsung Electronics Co Ltd|Non-Uniform Constellations|
    KR101461886B1|2013-09-10|2014-11-13|현대자동차 주식회사|Schottky barrier diode and method for manufacturing the same|
    EP2879318A1|2013-11-29|2015-06-03|Panasonic Corporation|Efficient component interleaving for rotated constellations with time-frequency slicing|
    WO2015079665A1|2013-11-29|2015-06-04|パナソニック株式会社|Transmission method, transmission device, receiving method, and receiving device|
    CN105471603B|2014-08-19|2020-12-11|中兴通讯股份有限公司|Method, device and system for remotely configuring PTPservice of optical network unit|
    KR101628986B1|2015-01-12|2016-06-10|강릉원주대학교산학협력단|Apparatus and method for transfering signal, apparatus and method for receiving signal|
    US9780854B2|2015-03-30|2017-10-03|Taiwan Semiconductor Manufacturing Co., Ltd.|Multi-layer wireless streaming with adaptive constellation mapping |
    EP3226501B1|2016-03-31|2020-02-19|Intel IP Corporation|Communication device and method for transmitting data|
    CN106130949B|2016-08-12|2019-05-10|上海交通大学|Higher-dimension constellation generation method and system|
    US10601521B2|2018-05-14|2020-03-24|Nokia Solutions And Networks Oy|Coherent optical communication with constellations having coordinates on circles|
    法律状态:
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    2018-02-27| B25A| Requested transfer of rights approved|Owner name: SUN PATENT TRUST (US) |
    2019-01-08| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2020-01-14| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2021-02-09| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-03-23| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 10 (DEZ) ANOS CONTADOS A PARTIR DE 23/03/2021, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    EP09168370A|EP2288048A1|2009-08-21|2009-08-21|Rotated multi-dimensional constellations for improved diversity in fading channels|
    EP09168370.6|2009-08-21|
    PCT/JP2010/005078|WO2011021382A2|2009-08-21|2010-08-17|Transmission apparatus, reception apparatus, transmission method, reception method, and method for generating multi-dimensional constellations|
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