Method and device for transmitting binary data - Patents.com

Abstract

A method is disclosed for transmitting binary data using an M-ASK constellation divided into M / 2 sets of two symbols, each set of index i containing the i-th symbol and the i+M / 2-th symbol of the constellation, with probability p i First, m-1 bits are obtained from equal probability binary sources, where m=log2M. Then, in response to the m-1 bits, a binary source is selected among the plurality of binary sources, and each binary source with index i is associated with p i The probability of outputting a zero bit is associated with a probability of 0, which is equal to m−1 bits as the less significant bits and the bit obtained from the selected source as the most significant bit. The symbols of the M-ASK constellation are obtained, which are associated with a binary word formed by the m−1 bits as the less significant bits and the bit obtained from the selected source as the most significant bit. The symbols are finally transmitted to a receiver via a communication channel.

Description

[Technical field]

[0001] At least one of the embodiments of the present invention generally relates to a method for transmitting binary data using an M-ASK constellation (ASK is the English acronym for "Amplitude-Shift Keying") and at least one of the embodiments of the present invention generally relates to a corresponding transmitter. [Background technology]

[0002] In a communication system, a transmitter is coupled to a receiver by a communication channel (e.g., an optical fiber). The transmitter usually includes an encoder configured to encode input data, e.g., a bit stream, into symbols belonging to a finite set called a constellation. One-dimensional ASK (English acronym for "Amplitude-Shift Keying") and two-dimensional QAM (English acronym for "Quadrature-Amplitude Keying") are examples of such constellations. Here, a one-dimensional or two-dimensional constellation is one in which the symbols are R or R, respectively. 2 This means that R takes values ​​in R, the set of real numbers.

[0003] These symbols are then transmitted over a communication channel to a receiver, which includes a decoder configured to decode the received symbols into output data.

[0004] In communication systems where uniformly distributed symbols are transmitted, shaping losses usually occur. It is therefore known that in order to approach the channel capacity, the transmitter must process the input data to change the probability distribution of the symbols to be transmitted. More precisely, the input data processes the symbols to be transmitted so that they have a non-uniform probability distribution that matches the communication channel. This operation is called stochastic shaping and achieves energy savings, also known as shaping gain. Alternatively, it is known that in Gaussian channels, the Maxwell-Boltzmann distribution leads to suboptimal performance. However, processing the input data to fit the Maxwell-Boltzmann distribution is complicated. Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore desirable to have a method for transmitting binary data that is high performance yet easy to implement, and that is adapted to non-Gaussian channels. [Means for solving the problem]

[0006] At least one of the embodiments of the present invention generally comprises a method in a transmitter for transmitting binary data using an M-ASK constellation divided into M / 2 sets of two symbols, each set of index i including the i-th symbol and the i+M / 2-th symbol of the M-ASK constellation, where i ∈ [1;M / 2], with a probability p i and the probability of transmitting the second symbol of the set, 1-p i and each symbol of the M-ASK constellation is associated with a binary word defined using natural labeling, and the method comprises: a) Obtaining m-1 bits from an equiprobable binary source, where m=log 2 Being M, b) selecting a binary source among the plurality of binary sources in response to the m-1 bits, each binary source having index i having p i and c) obtaining one bit from the selected source; and d) obtaining symbols of an M-ASK constellation associated with a binary word formed by the m-1 bits as less significant bits and the bit obtained from the selected source as the most significant bit; e) transmitting the resulting symbols to a receiver via a communication channel; and The present invention relates to a method comprising the steps of:

[0007] This transmission method is easier to implement than those that try to fit a Maxwell-Boltzmann distribution. More precisely, it makes it possible to implement the shaping operation with a small number of binary sources.

[0008] In one embodiment, selecting a binary source among the plurality of binary sources in response to the m-1 bits comprises: determining a decimal value of a binary sequence formed by the m-1 bits; selecting a binary source whose index is equal to the decimal value plus one; Includes.

[0009] In one embodiment, the plurality of binary sources includes: m-1 Contains binary sources.

[0010] In one embodiment,

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[0011] In one embodiment, each binary source of index i in the plurality of binary sources comprises:

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[0012] In one embodiment, the method comprises: encoding r×(M-1)*k bits obtained from an equiprobable binary source using an error-correcting code into (m-1)*n bits, where n and k are integers; Obtained from an equiprobable binary source

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[0013] In one embodiment, the method includes selecting a probability p from the table. i and transmitting to the receiver at least one index entry indicative of the obtained probability.

[0014] In one embodiment, the method comprises: i and transmitting the estimated probability to the receiver.

[0015] In one embodiment, the method comprises receiving from the receiver a probability p i The method further includes receiving the

[0016] At least one of the embodiments of the present invention generally relates to a transmitter configured to transmit binary data using an M-ASK constellation divided into M / 2 sets of two symbols, each set of index i including the i-th symbol and the i+M / 2-th symbol of the M-ASK constellation, where i ∈ [1;M / 2], and with a probability p i and each symbol of the M-ASK constellation is associated with a binary word defined using natural labeling. a) Obtaining m-1 bits from an equiprobable binary source, where m=log 2 Being M, b) selecting a binary source among the plurality of binary sources in response to the m-1 bits, each binary source having index i having p i and c) obtaining one bit from the selected source; and d) obtaining symbols of an M-ASK constellation associated with a binary word formed by the m-1 bits as less significant bits and the bit obtained from the selected source as the most significant bit; e) transmitting the resulting symbols to a receiver via a communication channel; and The device includes at least one processor configured to:

[0017] A computer program product is disclosed comprising program code instructions that can be loaded into a programmable device, the program code instructions causing the programmable device to perform a method according to any one of the embodiments when the program code instructions are executed by the programmable device.

[0018] A storage medium is disclosed that stores a computer program including program code instructions that, when read from the storage medium and executed by a programmable device, cause a method according to any one of the embodiments to be performed.

[0019] The characteristics of the invention will emerge more clearly on reading the following description of at least one example of embodiment, the said description being made with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 illustrates a schematic diagram of a communication system according to a particular embodiment. [Diagram 2] FIG. 2 illustrates symbols of the 8-ASK constellation. [Diagram 3] FIG. 2 illustrates the principle of the division of an M-ASK constellation into M / 2 sets of two symbols according to a particular embodiment; [Figure 4A] FIG. 2 is a block diagram of a shaping encoder according to a particular embodiment. [Figure 4B] FIG. 13 is a block diagram of a shaping encoder according to another particular embodiment. [Diagram 5] 4 is a flowchart of a transmission method according to a particular embodiment; [Figure 6] FIG. 13 is a block diagram of a shaping encoder according to another particular embodiment. [Figure 7] FIG. 13 is a block diagram of a shaping encoder according to another particular embodiment. [Figure 8] 4 is a flowchart of a decoding method according to a particular embodiment; [Figure 9] FIG. 2 illustrates a schematic diagram of an example of a hardware architecture of a shaping encoder according to a particular embodiment; [Figure 10] FIG. 2 is a schematic diagram illustrating an example of a hardware architecture of a decoding device according to a particular embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] 1 is a schematic diagram of a communication system 1 in which an embodiment of the present invention can be implemented. The communication system 1 comprises a transmitter 10 and a receiver 14 coupled together by a communication channel 12. The transmitter 10 is supplied with input data by at least one equiprobable binary source S0 and outputs selected symbols in a given alphabet X. The input data are, for example, bits of an audio / video bitstream. In one exemplary embodiment, the alphabet X is an M-ASK constellation, where M=2 m where m is an integer. The symbols of the M-ASK constellation are defined as follows:

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[0022] As a result, each symbol in this constellation has a magnitude of m=log 2The 8-ASK constellation can be represented by a sequence of M bits. Figure 2 shows the symbols of the 8-ASK constellation. The first symbol is -7 and the last symbol is 7. In the following, various embodiments are described with reference to ASK modulation. However, embodiments of the present invention are not limited to ASK modulation. For example, embodiments of the present invention may be used with QAM modulation.

[0023] In Figure 1, let X be a probability distribution p(x i )=p(X i =x i ), x i Let p(y|x i ), for example, for all x i For the Gaussian channel p(y|x i )~N(x i ,σ 2 ), let Y be the random variable of the communication channel output. For Gaussian channels, Y is defined as Y = X + W, where W is Gaussian noise, e.g., W ∼ N(0, σ 2 ).

[0024] For a Gaussian channel, the signal-to-noise ratio (SNR) is defined as:

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[0025] Specify any communication channel and press p * Let (x) be the distribution of input X that maximizes the mutual information (MI) for a given constellation.

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[0026]

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[0027] The goal of probabilistic shaping is to process the inputs such that their probability distributions maximize or nearly maximize the mutual information I(X;Y). In other words, the distribution of the inputs is

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[0028] For M-ASK constellations, p(x) is often chosen as MB distribution (the English acronym for “Maxwell-Boltzmann distribution”). In this case, the performance obtained is p * (x) (i.e., for small ε,

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[0029] According to a particular embodiment, in order to limit the complexity in the M-ASK case, the set of possible distributions is restricted to that expressed as follows: All

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[0030] Therefore, according to the present principle, the M-ASK constellation is divided into M / 2 sets, each set of index i having the i-th symbol and

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[0031] Thus, the shaping encoder according to one embodiment is configured to randomly select one set i of the M / 2 sets with equal probability (i.e., α) with probability p i Send the first symbol of set i with probability 1-p i The selection of the set may involve error-correcting codes. For each set i, we transmit the second symbol with probability pi is known by both the transmitter and the receiver.

[0032] In the first embodiment, the probability value p i is calculated offline for a given channel distribution. For example, for a Gaussian distribution of the noise in the channel, the probability value p i is calculated offline once and therefore does not change thereafter.

[0033] In the second embodiment, the probability value p i is calculated offline for a given range of parameters of the communication channel and stored in a table shared between the transmitter 10 and the receiver 14. For example, if the channel distribution is Gaussian, the parameter can be the SNR of this communication channel. Thus, in the table, p i One predefined set of values ​​is associated with each predefined range of SNR values, so that the transmitter 10 can select p from the table in response to the current SNR value. i A predetermined set of values ​​is selected and the receiver 14 is notified accordingly.

[0034] In a third embodiment, the channel distribution is estimated by the receiver 14 after receiving the pilot symbols. Then, the receiver 14 calculates p i The receiver 14 optimizes the values ​​of p and feeds them back to the transmitter 10 by using a signaling channel. Alternatively, the receiver 14 estimates the channel distribution and transmits the estimated channel distribution to the transmitter 10. The transmitter 10 i values ​​and feeds these back to the receiver 14. i The optimization of the set of values ​​can be a linear search, i.e., the set of possible p i Define a subset of values ​​and compute the mutual information associated with the estimated channel distribution. i The value is the one that maximizes the mutual information. i The set of values ​​is obtained by solving an optimization problem such as equation (1), where the following constraints, p i+M / 2 =1-p i ga pi applied to the value.

[0035] In the case of an M-ASK constellation, in which each symbol in the constellation is represented by a binary sequence with natural labelling with the more significant bit on the left, as shown in FIG. 3, the shaping encoder 100 can be implemented as shown in FIG. 4A and FIG. 4B. The shaping encoder 100 is part of the transmitter 10. The shaping encoder 100 comprises a switch 102 and a symbol mapper 104, and is configured to implement a shaping method as shown in the flowchart of FIG. 5. If necessary, the shaping encoder 100 can further comprise an ECC (English acronym of "Error-Correcting Code") module 106, also called a channel coding module. The ECC module 106 typically takes k*(m-1) bits as input and outputs n*(m-1) bits, where k and n are predefined integer values, for example k=500 and n=1000. For a given ratio k / n, the larger n*(m-1), the better the performance, while the latency increases with n*(m-1).

[0036] In FIG. 4A, the shaping encoder 100 includes binary sources S0 to S2. m-1 Bits are provided by S max Let S+1 be the number of distinct binary sources (i.e., including S0). max =2 m-1 The source S0 outputs bits with equal probability p(0) = p(1) = 1 / 2. m-1 Each source Si in ] has probability p i output a 0 bit with probability (1-p i ) to output a 1 bit.

[0037] In FIG. 4B, the shaping encoder 100 is fed bits by a single binary source S0 that outputs bits with equal probability p(0)=p(1)=1 / 2. In this case, the sources S1 to S2m-1 From this single source S0, for example, by using a binary DM (an acronym for "Distribution Matcher"), i.e., from sources S1 to S2 m-1 Binary DMs are disclosed, for example, in the document entitled "Polar coded distribution matching" by Boehnke et al., published in Electron. Lett., vol. 55, no. 9, pp. 537-539, 2019. However, embodiments of the present invention use a binary DM for each of the sources S1 to S2. m-1 The present invention is not limited to this particular method of obtaining

[0038] If the shaping encoder 100 of FIG. 4B does not include an ECC module for each given source S i , then D Mi takes as input the

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[0039] In the example in which the shaping encoder 100 of FIG. 4B comprises an ECC module 106 that encodes k*(m-1) bits into n*(m-1) bits and repeats this operation r times, each DMi has as input the

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[0040] Returning to FIG. 5, in step S300, (m-1) bits are obtained from source S0. In the following, these (m-1) bits are referred to as (b 1 ,b 2 ,...,b m-1 These (m-1) bits form the least significant bits of the symbol. The M-ASK constellation is

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[0041] In step S302, in response to the (m-1) bits obtained from S0, m-1 Among the binary sources, one source Si is selected by the switch 102. In fact, for each possible binary sequence of (m-1) bits, m-1 A set of (hence, 2 m-1 The index i of a selected set / source is a (m-1)-bit binary sequence (b 1 ,b 2 ,...,b m-1 )'s decimal value D(b 1 ,b 2 ,...,bm-1 ) incremented by 1, i.e., 1+D(b 1 ,b 2 ,...,b m-1 Each symbol in the constellation is represented by a binary sequence with natural labeling with the more significant bit on the left, and the value

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[0042] In step S304, a bit b m is obtained from this selected source. The obtained bit is the MSB of the symbol. Thus, the (m-1) bits obtained in S300 control a switch to select one source from which the MSB is output.

[0043] In step S306, the symbol mapper 104 generates a symbol to be transmitted corresponding to a binary word formed by the (m-1) bits taken as the LSBs in S300 and the selected bits taken as the MSBs in S304. The binary word is (b 1 ,b 2 ,...,b m-1 ,b m ), with the LSB on the left.

[0044] In step S308, the resulting symbols are transmitted to receiver 14 via communication channel 12. Steps S300 to S308 may be repeated for the next set of (m-1) bits.

[0045] If the shaping encoder 100 of FIG. 4A includes an ECC module 106 that outputs a set of n (m-1) bits, then the (m-1) bits of each set are independently used to select one source S i in step S302, thus producing one shaping bit b mIn other words, steps S300 to S308 are repeated for each set of (m−1) bits output by the ECC module 106.

[0046] Below, an example is given for M=8 and m=3, in which case the various sets are defined in the table below. [Table 2]

[0047] From the two bits "10" obtained from S0 in S300, the set of index 2 is selected, and so the switch 102 is positioned to select source S2 in S302. If the bit obtained from S2 in S304 is "1", the resulting binary word is "101", and so is mapped to symbol 3 of the constellation in S306. Symbol 3 is therefore output by the symbol mapper 104 and transmitted in S308.

[0048] In another example, where the two bits obtained from S0 in S300 are "11", the set with index 4 is selected in S302. The switch is positioned to source S4. If the bit obtained from S4 in S304 is "1", the symbol mapper outputs symbol 7 in S306 (corresponding to the binary word "111"). If the bit obtained from S4 in S304 is "0", the symbol mapper outputs symbol "-1" in S306 (corresponding to the binary word "110").

[0049] For some channels, such as Gaussian channels, p * (x) is symmetric. As a result,

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[0050] Considering this symmetry, the shaping encoder 100 of Fig. 4A can be further simplified as shown in Fig. 6. The number of binary sources is divided by 2 and bit reversal is used when some sources are selected. In this case, S max =2 m-2 It is.

[0051] b 1 ,b 2 ,...,b m-1 Let be the m-1 bits obtained from the binary source S0 at S300.

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[0052] Below we take an example for M=8 and m=3, in which case the various sets are represented in the table below: In this case, only three binary sources (S0, S1 and S2) are needed instead of five. [Table 3]

[0053] From the two bits "10" obtained from S0 in S300, the set of index 2 is selected, and so the switch 102 is positioned to select source S2 in S302. If the bit obtained from S2 in S304 is "1", the resulting binary word is "101", and so is mapped to symbol 3 of the constellation in S306. Symbol 3 is therefore output by the symbol mapper 104 and transmitted in S308.

[0054] In another example, where the two bits obtained from S0 in S300 are "11", then the set with index 4 is selected. Therefore, the switch 102 is positioned to select the source S1 in S302. If the bit obtained from S1 in S304 is equal to "1", it is inverted (i.e., changed to 0) by the inversion module 108. Finally, the symbol mapper outputs the symbol "-1" (corresponding to the binary word "110"). If the bit obtained from S1 in S304 is equal to "0", it is inverted (i.e., changed to 1) by the inversion module 108. Finally, the symbol mapper outputs the symbol "7" (corresponding to the binary word "111"). Thus, bit inversion is only applied when the sets with indexes 3 and 4 are selected.

[0055] In one variant (not shown in FIG. 6), the shaping encoder 100 is fed with bits by a single binary source S0 that outputs bits with equal probability p(0)=p(1)=1 / 2. In this case, the sources S1 to S2 m-2 From this single source S0, we use a binary DM (an English acronym for “distribution matcher”) to generate S1-S2 distributions in the same way as shown in Figure 4B. m-2 Thus, if the shaping encoder does not have an ECC module for each given source Si, DMi takes as input the

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[0056] In the example where the shaping encoder comprises an ECC module that encodes k*(m-1) bits into n*(m-1) bits and repeats this operation r times, each DMi has as input the

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[0057] To further reduce the complexity, the number of distinct binary sources can be reduced by forcing adjacent symbols to have the same probability. For example, for 8-ASK, p 2 HAp 1 The symbols associated with the same pi select bits from the same binary source. S max Even if is small (e.g., equal to 2),

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[0058] Typically, only a single equiprobable binary source S0 is available. For this reason, as shown in FIG. 4B, the additional binary sources are derived from the single binary source S0. FIG. 7 shows a shaped encoder 100 according to a particular embodiment in which two additional binary sources are derived from the single binary source S0. In this embodiment, S max = 2 and bits must be processed packet by packet (e.g., due to latency or system constraints). i ) is the parameter p i Let us denote the binary entropy with the following formula:

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[0059] Switch to first DM

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[0060] Once the M-ASK symbols are obtained using any of the above-mentioned shaping coders described with respect to Figures 4A-7, the transmitter 10 transmits them over several dimensions, such as polarization, time, frequency and space. For example, the transmitter 10 can group two ASK symbols in a complex symbol, one real part and the other imaginary part. In this case, the M-ASK modulation is also called QAM modulation.

[0061] In various embodiments, the shaping encoder 100 may optionally include an ECC module 106 that is used to code the less significant bits. In one example, the ECC module is configured to code these bits using multi-level polar coding. The principles of multi-level coding are explained below.

[0062] Using the chain rule, the mutual information between input X and output Y of a communication channel can be expressed as:

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[0063] The 1-bit level is I(B i ;Y|B 1 ,...,B i-1 When transmitting information across this i-th level using a binary code, the coding rate is I(B i ;Y|B 1 ,...,B i-1 ) In practice, a backoff is applied that depends on the code used. The communication channel can also be characterized by the log-likelihood ratio (LLR).

[0064] B 1 =b 1 ,...,B i-1 =b i-1 Given,

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[0065] Since the bits at the first level remain equally probable, p(B i =1|B 1 =b 1 ,...,B i-1 =b i-1 )=p(B i =0|B 1 =b1 ,...,B i-1 =b i-1 )=0.5 and the mutual information is calculated as follows:

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[0066] Regarding the last bit level used for formatting,

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[0067] For the range of SNRs considered, the shaped bits b m does not need to be encoded with a channel code. The mutual information I(Y;B m |B 1 ,...,B m-1 ) is equal to the entropy of the corresponding level, i.e. the communication channel is “clean”. Therefore, the shaped bit b m is not encoded with a channel code in the above disclosed embodiment. As a result, the value of k in FIG.

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[0068] Then, multi-level polar coding simply means that each bit level has a rate I(Y;B i |B 1 ,...,B i-1 ) The block length refers to the size of the polar code used.

[0069] At the receiver side, the polar codes are decoded using list decoding, which is disclosed in the document by Tal et al. entitled "List decoding of polar codes", published in IEEE Transactions on Information Theory, vol. 61, n°5, pages 2213-2226 in 2013. The list decoder performs MAP decoding. As a result, the decoder takes the LLRs as input (see equation (2)), which requires knowledge of the input distribution to be computed. In other words, the receiver uses p i You need to know the value of .

[0070] FIG. 8 shows a flow chart of a decoding method according to a particular embodiment.

[0071] In step S400, the index i of the set of sources selected at the transmitter in step S302 is first obtained. If the set selection is performed block-wise by the transmitter using an error correction code, the index i is obtained by channel decoding (i.e., a block of indexes of the set are decoded together).

[0072] In step S402, when the set index i is decoded, one of the two symbols in set i is detected based on the received y. Most channel decoders perform maximum a posteriori (MAP) decoding. The detection of the transmitted symbols in set i can also perform MAP detection. MAP decoding requires knowledge of the input distribution. In other words, the receiver needs to know p for efficient decoding. i You need to know the value of .

[0073] In some cases, it is sufficient to perform maximum likelihood (ML) detection on set i because it is reliable enough that we do not need to take the posterior probability into account. As a result, p i Knowledge of can only be used by the channel decoder.

[0074] In step S404, inverse mapping is applied to recover bits from the detected symbols. This step is the inverse of step S306. In step S406, the inverse of step S302 is applied. Thus, the switch 102 is positioned to send the MSB bits to the appropriate source. If binary DM is used at the transmitter side, inverse binary DM can also be applied.

[0075] If bit reversal is applied at the transmitter side, then bit reversal is applied at the receiver side by the inversion module 108 in step S406.

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[0076] FIG. 9 illustrates a schematic diagram of an example hardware architecture of a transmitter 10 in accordance with a particular embodiment.

[0077] The transmitter 10 comprises a processor or CPU (acronym for "Central Processing Unit") 111, a random access memory RAM 112, a read-only memory ROM 113, a storage unit STCK 114 such as a hard disk or a storage medium reader, e.g. an SD (acronym for "Secure Digital") card reader, connected by a communication bus 110, and at least one set of communication interfaces COM 115 that enable the transmitter 10 to send and receive data.

[0078] The processor 111 is capable of executing instructions loaded into the RAM 112 from the ROM 113, from an external memory (such as an SD card), from a storage medium (such as an HDD), or from a communication network. When the transmitter 10 is powered on, the processor 111 is capable of reading and executing instructions from the RAM 112. These instructions form a computer program that causes the processor 111 to perform the methods described with respect to Figures 4A-7.

[0079] The methods described with respect to Figures 4A-7 can be implemented in the form of software by execution of a set of instructions by a programmable machine, for example a DSP (acronym for "Digital Signal Processor"), a microcontroller or a GPU (acronym for "Graphics Processing Unit"), or in the form of hardware by a machine or dedicated components (chips or chipsets), for example an FPGA (acronym for "Field-Programmable Gate Array") or an ASIC (acronym for "Application-Specific Integrated Circuit"). In general, the transmitter 10 includes electronic circuitry adapted and configured to implement the methods described with respect to Figures 4A-7.

[0080] FIG. 10 illustrates generally an example of a hardware architecture for receiver 14, in accordance with a particular embodiment.

[0081] The receiver 14 comprises a processor or CPU (acronym for "Central Processing Unit") 201, a random access memory RAM 202, a read-only memory ROM 203, a storage unit STCK 204 such as a hard disk or a storage medium reader, e.g. an SD (acronym for "Secure Digital") card reader, connected by a communication bus 210, and at least one set of communication interfaces COM 205 that enable the receiver 14 to send and receive data.

[0082] The processor 201 is capable of executing instructions loaded into the RAM 202 from the ROM 203, from an external memory (such as an SD card), from a storage medium (such as an HDD), or from a communication network. When the receiver 14 is powered on, the processor 201 is capable of reading and executing instructions from the RAM 202. These instructions form a computer program that causes the processor 201 to perform the methods described with respect to Figures 4A-7.

[0083] The method described with respect to Fig. 8 can be implemented in the form of software by execution of a set of instructions by a programmable machine, for example a DSP (acronym for "Digital Signal Processor"), a microcontroller or a GPU (acronym for "Graphics Processing Unit"), or in the form of hardware by a machine or dedicated component (chip or chipset), for example an FPGA (acronym for "Field-Programmable Gate Array") or an ASIC (acronym for "Application-Specific Integrated Circuit"). In general, the receiver 14 includes electronic circuitry adapted and configured to implement the method described with respect to Fig. 8.

Claims

1. 1. A method for transmitting binary data using a M-ASK constellation divided into M / 2 sets of two symbols at a transmitter, comprising: Each set of index i contains the i-th and i+M / 2-th symbols of the M-ASK constellation, where i ∈ [1; M / 2], and has a probability p ｉ and the probability of transmitting the second symbol of the set, 1−p ｉ and each symbol of the M-ASK constellation is associated with a binary word defined with a more significant bit on the left natural labeling, the method comprising: a) obtaining m-1 bits from an equiprobable binary source that outputs 0 bits and 1 bits with equal probability 1 / 2, where m=log ２ Being M, b) selecting a binary source among a plurality of binary sources in response to the m-1 bits, each binary source having index i having p ｉ and c) obtaining one bit from the selected binary source; and d) obtaining symbols of the M-ASK constellation associated with the binary word formed by the m-1 bits as less significant bits and a bit obtained from a selected binary source as a most significant bit; e) transmitting the resulting symbols to a receiver via a communication channel; A method comprising:

2. Selecting a binary source among a plurality of binary sources in response to the m-1 bits includes: determining a decimal value of a binary sequence formed by said m-1 bits; selecting a binary source whose index is equal to said decimal value plus one; The method of claim 1 , comprising:

3. The plurality of binary sources include: ｍ－１ The method of claim 1 or 2, further comprising: 【Request 4】 【Number 1】 and the plurality of binary sources are: ｍ－２ selecting a binary source in response to the m-1 bits, determining a decimal value D of a binary sequence formed by said m-1 bits; [0025] selecting a binary source whose index is equal to M / 2-D if otherwise, selecting a binary source whose index is equal to said decimal value plus one; Including, 4. The method of claim 3, wherein if a binary source with index equal to M / 2-D is selected, bits obtained from the selected binary source are inverted before obtaining the symbols of the M-ASK constellation.

5. Each binary source of index i in the plurality of binary sources has [0030] By applying binary distribution matching to a sequence of bits obtained from the equiprobable binary source, S ｍａｘ is the number of sources in the multiple binary sources, and H(p ｉ ) is the parameter p ｉ The method according to any one of claims 1 to 4, wherein r is an integer equal to or greater than 1, and r represents a binary entropy having the following formula:

6. The method comprises: encoding r×(M−1)*k bits obtained from said equiprobable binary source using an error correcting code into (m−1)*n bits, where n and k are integers; The equiprobable binary source [0045] obtaining each binary source of index i in the plurality of binary sources from the equal probability binary sources by applying binary distribution matching to a sequence of bits, comprising: ｍａｘ is the number of sources in the plurality of binary sources, and H(p ｉ ) is the parameter p ｉ Denote the binary entropy with applying a) to e) to each of n sets of (m−1) bits; The method of any one of claims 1 to 4, further comprising:

7. From the table, the probability p ｉ and transmits the obtained probability p ｉ The method of claim 5 or 6, further comprising transmitting at least one index entry indicating:

8. Given a communication channel distribution, probability p ｉ 7. The method of claim 5 or 6, further comprising estimating the probability ? ? and transmitting the estimated probability to the receiver.

9. The receiver receives the probability p ｉ The method of claim 5 or 6, further comprising receiving:

10. 1. A transmitter configured to transmit binary data using an M-ASK constellation divided into M / 2 sets of two symbols, each set of index i including the i-th symbol and the i+M / 2-th symbol of the M-ASK constellation, where i ∈ [1;M / 2], with a probability p ｉ and each symbol of the M-ASK constellation is associated with a binary word defined using natural labelling with the less significant bit on the left, and the transmitter a) obtaining m-1 bits from an equiprobable binary source that outputs 0 bits and 1 bits with equal probability 1 / 2, where m=log ２ Being M, b) selecting a binary source among a plurality of binary sources in response to the m-1 bits, each binary source having index i having p ｉ and c) obtaining one bit from the selected binary source; and d) obtaining symbols of the M-ASK constellation associated with the binary word formed by the m-1 bits as less significant bits and the bit obtained from the selected binary source as most significant bit; e) transmitting the resulting symbols to a receiver via a communication channel; 13. A transmitter comprising: at least one processor configured to:

11. A computer program comprising program code instructions loadable into a programmable device, said program code instructions causing the implementation of a method according to any one of claims 1 to 9 when said program code instructions are executed by said programmable device.

12. A storage medium storing a computer program comprising program code instructions which, when read from the storage medium and executed by a programmable device, cause a method according to any one of claims 1 to 9 to be performed.

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