KR20230141188A - A method and apparatus for communication using two shifted quadrature amplitude modulation constellations - Google Patents

Abstract

The present invention relates to a communication method and device using two shifted orthogonal amplitude modulation constellations. A method of operating a transmitting node for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention includes (a) system variables including a bias value and modulation order based on the channel state; determining; (b) determining an odd bit-based constellation using the bias value and modulation order; (c) generating a symbol by performing modulation based on the odd bits using the odd bit-based constellation; and (d) transmitting the generated symbol to a receiving node.

Description

{A method and apparatus for communication using two shifted quadrature amplitude modulation constellations}

The present invention relates to a communication method and device using two shifted orthogonal amplitude modulation constellations, and more specifically, to a communication method and device using an odd bit-based constellation.

The modulation methods used in 5G and wireless communication standards are determined by factors such as data rate, bandwidth, and power efficiency required to transmit information, as well as channel conditions and demodulation complexity.

The square-QAM constellation, which has an even number of transmission bits per symbol, has been used in wireless communication standards because it has low computational complexity for soft-decision values.

The modulation method specified by the 5G standard has a modulation order of When you say It supports quadrature phase shift keying (QPSK) of 2, 4, 6, and 8, and quadrature amplitude modulation (QAM) of 16, 64, and 256QAM. Compared to even-bit QAM, odd-bit QAM can achieve higher data rates in the boundary area of even-bit QAM, but has not been mainly used in wireless communication standards because of its high demodulation complexity.

[Patent Document 1] Korean Patent No. 10-2012258

The present invention was created to solve the above-described problems, and its purpose is to provide a communication method and device using two shifted orthogonal amplitude modulation constellations.

In addition, the purpose of the present invention is to provide a communication method and device using an odd-bit non-square-QAM constellation designed by modifying the form of square-QAM and a chain decoding based coding technique suitable therefor.

In addition, the present invention is designed by modifying two square-QAM through bias values, and the bias value and channel with optimal capacity in a given channel state through BICM (Bit-interleaved coded modulation) capacity table. The purpose is to provide a communication method and device that uses a constellation to determine the code rate used for coding.

The objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned can be clearly understood from the description below.

In order to achieve the above objectives, a method of operating a transmitting node for communicating using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention includes (a) setting a bias value based on the channel state; and determining system variables including modulation order; (b) determining an odd bit-based constellation using the bias value and modulation order; (c) generating a symbol by performing modulation based on the odd bits using the odd bit-based constellation; and (d) transmitting the generated symbol to a receiving node; may include.

In an embodiment, step (b) includes determining an even bit-based constellation using the modulation order; determining a first constellation in which the even bit-based constellation is shifted in a positive direction by the bias value and a second constellation in which the even-bit-based constellation is shifted in a negative direction by the bias value; and determining the odd bit-based constellation using the first constellation and the second constellation.

In an embodiment, the odd bits include the even bits and a most significant bit (MSB), and when the MSB is 0, the symbol is generated based on the first constellation, and when the MSB is 1 , the symbol may be generated based on the second constellation.

In an embodiment, step (c) may include mapping the symbols per even-numbered bits and MSBs using the odd-bit-based constellation.

In an embodiment, step (c) includes generating information bits based on the block length of the modulation order and channel code included in the system variable; Separating the information bits into first bits input to a first codeword encoder and second bits input to a second codeword encoder; A first codeword is generated from the first bits through the first codeword encoder based on the first code rate included in the system variable, and the second codeword is based on the second code rate included in the system variable. generating a second codeword from the second bit through an encoder; Interleaving the first codeword according to a first random arrangement having the same length as the first codeword, and interleaving the second codeword according to a second random arrangement having the same length as the second codeword. step; generating a bit stream by merging the interleaved first and second codewords bit by bit; and mapping the generated bit stream to the symbol per odd bit using the odd bit-based constellation.

In an embodiment, a method of operating a receiving node to communicate using two shifted orthogonal amplitude modulation constellations includes the steps of: (a) receiving a symbol from a transmitting node; (b) decoding the first codeword of the symbol; (c) determining the type of even bit-based constellation according to the most significant bit (MSB) of the decoding result of the first codeword; and (d) decoding the second codeword of the symbol based on the type of the even bit-based constellation.

In an embodiment, step (c) includes, when the MSB of the decoding result of the first codeword is 0, generating a first constellation by shifting the even bit-based constellation in the positive direction by a bias value. ; And when the MSB of the decoding result of the first codeword is 1, generating a second constellation by shifting the even bit-based constellation in a negative direction by the bias value.

In an embodiment, step (b) includes calculating a log-likelihood ratio (LLR) for the first codeword; Deinterleaving the LLR for the first codeword according to a first random arrangement having the same length as the first codeword; and decoding the deinterleaved LLR through a first codeword decoder to generate a decoded first bit based on the block length of the channel code.

In an embodiment, the method of operating a receiving node for communicating using the two shifted orthogonal amplitude modulation constellations includes, before step (d), the first random array having the same length as the first codeword. It may further include interleaving the first bit.

In an embodiment, step (d), when the interleaved first bit is 0, generates the second codeword based on the first constellation in which the even bit-based constellation is shifted in the positive direction by a bias value. Calculate the LLR for, and when the interleaved first bit is 1, calculate the LLR for the second codeword based on the second constellation in which the even bit-based constellation is shifted in the negative direction by the bias value. steps; Deinterleaving the LLR for the second codeword according to a second random arrangement having the same length as the second codeword; and decoding the deinterleaved LLR through a second codeword decoder to generate decoded second bits based on the block length and even number of bits of the channel code.

In an embodiment, a transmitting node device for communicating using two shifted orthogonal amplitude modulation constellations determines system variables including a bias value and a modulation order based on a channel state, and determines the bias value and the modulation order. a control unit that determines an odd bit-based constellation using an order, and generates a symbol by performing modulation based on the odd bits using the odd bit-based constellation; and a transmitting unit that transmits the generated symbol to the receiving node.

In an embodiment, the control unit determines an even-bit-based constellation using the modulation order, and shifts the even-bit-based constellation in a positive direction by the bias value and shifts the even-bit-based constellation in a negative direction. The second constellation shifted by the value is determined, and the odd bit-based constellation can be determined using the first constellation and the second constellation.

In an embodiment, the odd bits include the even bits and a most significant bit (MSB), and when the MSB is 0, the symbol is generated based on the first constellation, and when the MSB is 1 , the symbol may be generated based on the second constellation.

In an embodiment, the control unit may map the symbols per even bit and MSB using the odd bit-based constellation.

In an embodiment, the control unit generates an information bit based on the modulation order and the block length of the channel code included in the system variable, and converts the information bit into the first bit and the second code input to the first codeword encoder. It is separated into a second bit input to the encoder, and a first codeword is generated from the first bit through the first codeword encoder based on the first code rate included in the system variable. Generating a second codeword from the second bits through the second codeword encoder based on a second code rate, and interleaving the first codeword according to a first random arrangement having the same length as the first codeword ( interleaving), interleaving the second codeword according to a second random arrangement having the same length as the second codeword, and merging the interleaved first codeword and the second codeword bit by bit to generate a bit stream; , the generated bit string can be mapped to the symbol per odd bit using the odd bit-based constellation.

In an embodiment, a receiving node device for communicating using two shifted orthogonal amplitude modulation constellations includes: a receiving unit that receives a symbol from a transmitting node; and decoding the first codeword of the symbol, determining the type of the even-bit-based constellation according to the most significant bit (MSB) of the decoding result of the first codeword, and determining the type of the even-bit-based constellation based on the type of the even-bit-based constellation. It may include a control unit that decodes the second codeword of the symbol.

In an embodiment, when the MSB of the decoding result of the first codeword is 0, the control unit generates a first constellation in which the even bit-based constellation is shifted in the positive direction by a bias value, and the first When the MSB of the codeword decoding result is 1, a second constellation can be generated by shifting the even bit-based constellation in the negative direction by the bias value.

In an embodiment, the control unit calculates a log-likelihood ratio (LLR) for the first codeword, and calculates the LLR for the first codeword according to a first random sequence having the same length as the first codeword. By deinterleaving and decoding the deinterleaved LLR through a first codeword decoder, the decoded first bit can be generated based on the block length of the channel code.

In an embodiment, the control unit may interleave the first bits according to a first random arrangement having the same length as the first codeword.

In an embodiment, when the interleaved first bit is 0, the control unit determines the LLR for the second codeword based on the first constellation obtained by shifting the even bit-based constellation in the positive direction by a bias value. Calculate, and when the interleaved first bit is 1, calculate the LLR for the second codeword based on the second constellation in which the even bit-based constellation is shifted by a bias value in the negative direction, and The LLR for the second codeword is deinterleaved according to a second random arrangement having the same length as the second codeword, and the deinterleaved LLR is decoded through a second codeword decoder to determine the block length and even number of the channel code. A second decoded bit can be generated based on the bit.

Specific details for achieving the above objectives will become clear by referring to the embodiments described in detail below along with the attached drawings.

However, the present invention is not limited to the embodiments disclosed below, and may be configured in various different forms. In order to ensure that the disclosure of the present invention is complete, those skilled in the art ( It is provided to fully inform those skilled in the art of the invention of the scope of the invention.

According to an embodiment of the present invention, communication efficiency can be increased by using an odd-bit non-square-QAM constellation designed by modifying the form of square-QAM and a chain decoding based coding technique suitable for the odd-bit non-square-QAM constellation.

The effects of the present invention are not limited to the effects described above, and potential effects expected by the technical features of the present invention can be clearly understood from the description below.

Figure 1 is a diagram illustrating a communication system using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.
Figure 2 is a diagram illustrating an example of an odd bit-based constellation according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating the functional configuration of a transmitting node for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.
Figure 4 is a diagram showing a bit string merged through a serial merger according to an embodiment of the present invention.
Figure 5 is a diagram illustrating the functional configuration of a receiving node for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.
Figures 6a and 6b are diagrams showing BICM capacity graphs for each codeword length according to an embodiment of the present invention.
Figure 7 is a diagram showing a decision section of BQAM according to an embodiment of the present invention.
FIG. 8 is a diagram illustrating a method of operating a transmitting node for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.
FIG. 9 is a diagram illustrating a method of operating a receiving node for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.
FIG. 10 is a diagram illustrating another functional configuration of a transmitting node device for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.
FIG. 11 is a diagram illustrating another functional configuration of a receiving node device for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.

Since the present invention can be subject to various changes and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail.

The various features of the invention disclosed in the claims may be better understood by consideration of the drawings and detailed description. The apparatus, method, manufacturing method, and various embodiments disclosed in the specification are provided for illustrative purposes. The disclosed structural and functional features are intended to enable those skilled in the art to specifically implement various embodiments, and are not intended to limit the scope of the invention. The disclosed terms and sentences are intended to easily explain various features of the disclosed invention and are not intended to limit the scope of the invention.

In describing the present invention, if it is determined that a detailed description of related known technology may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

Hereinafter, a communication method and device using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention will be described.

Figure 1 is a diagram illustrating a communication system 100 using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.

Referring to FIG. 1, the communication system 100 may include a transmitting node 110 and a receiving node 120.

The transmitting node 110 can convert binary bits into signals using an odd bit-based non-square-QAM constellation designed by modifying the form of square-QAM (Quadrature Amplitude Modulation).

The constellation according to the present invention can be created by modifying two square-QAMs through a bias value.

Additionally, the transmitting node 110 can determine a bias value with optimal capacity in a given channel state and a code rate used for channel coding through a bit-interleaved coded modulation (BICM) capacity table.

In one embodiment, in the case of an odd bit-based constellation according to the present invention, the type of constellation to which a symbol is mapped may be determined through the most significant bit (MSB). These features can be applied to channel coding techniques.

In one embodiment, the odd bit-based constellation may be referred to as a bias-based constellation, a Bias-QAM (BQAM) constellation, or a term with equivalent technical meaning.

When decoding, the receiving node 120 may first perform decoding on the MSB of the first codeword and decode the second codeword through the decoding result.

Therefore, in order to calculate the LLR for the second codeword, the receiving node 120 may determine and calculate the type of square-QAM used for LLR calculation according to the decoding result bits of the first codeword.

The present invention proposes an odd-bit non-square-QAM constellation designed by modifying the form of square-QAM and a chain decoding-based coding technique suitable for it.

Figure 2 is a diagram illustrating an example of an odd bit-based constellation according to an embodiment of the present invention.

Referring to FIG. 2, the BQAM constellation according to the present invention can be created as a QAM with a modulation order of 2M by overlapping two types of QAM with a modulation order of M in which an even-bit QAM is shifted through a bias value.

In one embodiment, if m is an even number, a QAM with a modulation order of 2M made of two square-QAMs with a modulation order of M may be an odd bit-based non-square-QAM.

In one embodiment, square-QAM with modulation order M is When you say A constellation that is shifted by +bias with respect to the real and imaginary axes in the complex plane. , -The constellation shifted by the bias You can decide.

The transmitting node 110 is In addition to the bit transmitted through, one additional bit is transmitted, and if this bit value is 0, the symbol value is modulates, and if the bit value is 1, It is modulated with , and this bit can be determined as the MSB (most significant bit) of the symbol.

The constellation designed in this way has a modulation order of Transmitting via QAM bit and MSB 1 bit, resulting in 1 bit per symbol. Bits can be transmitted, and the constellation designed in this way can be referred to as Bias-QAM (BQAM).

for example, , As an example, the constellation of 16QAM is If you set the bias value to 0.8, and The constellation is , It can be expressed as

The constellation designed according to the example above is 32BQAM. It is expressed as , and when expressed on the complex plane, it can be as shown in Figure 2.

In one embodiment, the bias value and modulation order are Even bits are odd bits created through QAM -BQAM can be expressed as <Equation 1>.

FIG. 3 is a diagram illustrating the functional configuration of a transmitting node 110 for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention. Figure 4 is a diagram showing a bit string merged through a serial merger according to an embodiment of the present invention.

Referring to FIG. 3, the transmitting node 110 may include a control unit 310 and a transmitting unit 320.

The control unit 310 includes a system variable setting unit 311, a bit generation unit 312, a bit separator 313, a first codeword encoder 314, a second codeword encoder 315, and a first codeword interleaver ( 316), a second codeword interleaver 317, a serial merger 318, and a BQAM modulator 319.

The system variable setting unit 311 can set system variables required by the transmitting node 110. In one embodiment, the system variable is modulation order , block length of channel symbol , bias value of BQAM, code rate of two codewords may include.

Here, the bias value and is determined by a capacity table calculated by the modulation order, channel status, and block length, and may be a table calculated and presented in advance.

The transmitting node 110 calculates the signal-to-noise ratio (SNR), which is the channel state, and calculates this with a bias value corresponding to the SNR value presented in the capacity table. can be decided.

In one embodiment, calculating the capacity table is detailed in Figures 6A and 6B below.

In one embodiment, the bit generator 312 may generate an information bit (message bit).

In one embodiment, the number of information bits may be determined by the modulation order and the block length of the channel code. The information bits input to the bit separator 312 are It can be a randomly generated bit string.

In one embodiment, since BQAM of the present invention uses two codewords, the bit separator 313 can separate information bits to be input to two encoders. The bit separator 312 inputs the information bits to the first code word encoder. input to the first bits and the second codeword encoder It can be separated into two second bits.

In one embodiment, each of the first and second bits separated by the bit separator 313 may be input to the first codeword encoder 314 and the second codeword encoder 315. The first codeword encoder 314 and the second codeword encoder 315 have respective code rates. It can be encoded as

This means that the number of information bits for the first codeword is And the number of information bits of the second codeword is , and the number of output bits of each encoder is When , each code rate is This may mean that it is established. Bit string encoded as the output of the first codeword encoder 314 and the second codeword encoder 315 (i.e., codeword class ) is generated, and the number of each bit is , It can be.

Codeword encoded through each encoder class Each may be interleaved through a first codeword interleaver 316 and a second codeword interleaver 317. The first codeword interleaver 316 is a codeword An array generated from a random pattern with a length equal to the length of generates, and the second codeword interleaver 317 generates a codeword An array generated from a random pattern with a length equal to the length of can be created.

The first codeword interleaver 316 has a length array According to the arrangement of Reverse the order of the bit strings, and the resulting interleaved bit strings This outputs, and the second codeword interleaver 317 has the length array to fit the arrangement of Reverse the order of the bit strings and the resulting interleaved bit strings This can be printed. Generated Random Array class Can be used in the receiving node 120 for deinterleaving after passing the channel.

Serial Concatenation (318) is class A bit string that merges two bit strings of can be created. bit string is one bit of the first codeword and the second codeword. Since the bits are merged in order, class These can be mixed and merged. In one embodiment, merged bit strings This generated structure can be shown as in Figure 4.

The total number of bits of the bit string input to the BQAM modulator 319 is As, the BQAM modulator 319 is One symbol can be mapped per bit.

The transmitter 320 can transmit N symbols to the receiving node 120 using the BQAM constellation and bit mapping designed by the bias value.

FIG. 5 is a diagram illustrating the functional configuration of a receiving node 120 for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.

Referring to FIG. 5, the receiving node 120 may include a receiving unit 510 and a control unit 520.

The control unit 520 includes a first codeword LLR calculator 521, a first codeword deinterleaver 522, a first codeword decoder 523, a first codeword interleaver 524, and a second codeword LLR calculator ( 525), a second codeword deinterleaver 526, and a second codeword decoder 527.

The signal modulated through the transmitting node 110 may be received by the receiving node 120 with noise added. for example, Among the transmission symbol values the second symbol , among the received symbol values the second symbol , Additive white Gaussian noise added to each symbol. White Gaussian noise has a mean of 0 and a variance of It can follow a complex Gaussian distribution.

In one embodiment, The received value may satisfy <Equation 2>.

The first codeword log-likelihood ratio (LLR) calculator 521 can calculate the soft-decision of the received value and use it for decoding. In one embodiment, BQAM according to the present invention may use a coding technique based on sequential cancellation (SC). Therefore, during decoding, the MSB is decoded first, and the second codeword can be decoded through the decoding result.

In one embodiment, the soft decision value input to the decoder is calculated through LLR calculation, and can be expressed as <Equation 3>.

In one embodiment, is a symbol Among the bits that make up When referring to the th bit, It can be.

In one embodiment, the LLR value for the first codeword is This is the value when is 1, for one symbol Expressed as LLRs can be output.

In one embodiment, <Equation 3> can reduce computational complexity through max-log MAP (max-log maximum a posteriori) and approximation techniques, which is explained in FIG. 7 .

In one embodiment, the first codeword deinterleaver 522 calculates the LLR for the first codeword using the LLR calculation value used by the transmitting node 110. By deinterleaving in the original bit string order through array, LLR values can be output.

In one embodiment, the first codeword decoder (Decoder) 423 may decode the deinterleaved LLR value. If the decoding result is 0, the constellation of the received value is is determined, and if the decoding result is 1, can be decided. block length Total according to decoded bits can be output. is the primary output of the receiving node 120, and is the primary output of the transmitting node 110. It may be a decoded bit string.

The first codeword interleaver 524 is the output of the first codeword decoder 523. used by the transmitting node 110. Interleaving is possible through arrays. interleaved Decoding of the second codeword may proceed through .

The second codeword LLR calculator 525 receives as input It is possible to distinguish the type of equation used for calculating the LLR of the second codeword. In the BQAM constellation structure, if the MSB bit of a symbol is 0, the remaining bits other than the MSB bit are square-QAM. is modulated, and if the MSB bit is 1, can be modulated.

Accordingly, the second codeword LLR calculator 525 can calculate the LLR by determining the type of square-QAM used for LLR calculation according to the decoding result bits of the first codeword.

That is, the second codeword LLR calculator 525 is If the bit of is 0, the LLR can be calculated using <Equation 4>, and if the bit is 1, using <Equation 5>.

In addition, square-QAM has the advantage of low LLR calculation complexity and uses a decoding technique of sequential elimination that reduces the type of constellation used when calculating LLR for the second codeword by half through the decoding result of the first codeword. You can have it.

-One symbol per BQAM Since LLR for bits is output, for one symbol It is expressed as LLRs can be output.

The second codeword deinterleaver 526 calculates the LLR for the second codeword using the LLR value used in the transmitting node 110. Deinterleaved in the original bit string order through array LLR values can be output.

The second codeword decoder 527 can decode the deinterleaved LLR value. For block length N bit string is output, which is used as the secondary output of the receiving node 120. It may be a decoded bit string.

Figures 6a and 6b are diagrams showing BICM capacity graphs for each codeword length according to an embodiment of the present invention.

Referring to FIGS. 6A and 6B, the transmitting node 110 can set the code rate and bias value of the encoder.

In one embodiment, transmitting node 110 may calculate BICM capacity.

According to the present invention, BICM (Bit-interleaved coded Modulation) capacity according to random coding exponent can be analyzed for the code rate for the first codeword and the second codeword for BQAM. A coding technique based on sequential cancellation (SC) can be applied to the BQAM constellation.

In addition, since the constellation is designed by adjusting the bias value, the transmitting node 110 obtains an indicator value through capacity calculation and determines the code rate and bias value according to the channel through the obtained capacity table. .

In one embodiment, the equation for calculating the capacity can be expressed as <Equation 6> to <Equation 8>. The error probability different from the random coding exponent is defined by <Equation 6>, and the random coding exponent for BICM can be defined by <Equation 7> and <Equation 8>.

Target frame error probability (target FER, target frame error rate) By setting <Equation 6>, the BICM capacity that satisfies the error probability for each block length can be calculated.

The capacity of BQAM is a sequential removal structure, so the capacity for the first codeword and capacity for the second codeword It can be calculated by dividing by , and the capacity for the entire length is It can be expressed as

each Each bias value is calculated differently, and only the bias value with the maximum capacity can be displayed. Figures 6a and 6b show each of 32BQAM Indicates the capacity for the bias value that satisfies the maximum capacity.

The capacity of 16QAM and the capacity _{of 32} Figure 6a shows the BICM capacity for a code where the length of codeword 1 is 512, and Figure 6b shows the BICM capacity for a code with a length of 2048.

In one embodiment, the transmitting node 110 may set LDPC parameters.

The transmitting node 110 may perform decoding of the second codeword based on the decoding result of the first codeword through BQAM.

For example, <Table 1> is based on the capacities derived from Figures 6a and 6b. and the target optimal bias value at 1dB intervals. can represent.

For example, <Table 2> may indicate the coding rate set by applying a uniform gap.

Since the capacity derived in Figures 6a and 6b is a value obtained through random coding exponent, for performance comparison, a bias value with optimal frequency efficiency for each block length can be fixed and the capacity value from the corresponding table can be applied. .

For the LDPC code used, the code rate can be adjusted for each block length and the gap can be set to a uniform value to satisfy the target frame error probability as a result of the performance.

Additionally, if a rate lower than the minimum rate that can operate in the used 5G NR LDPC channel code is required, the minimum rate that can operate can be applied. length 512 The gap is 0.04, 0.05 and 2048 The gap may be 0.05 or 0.04.

Figure 7 is a diagram showing a decision section of BQAM according to an embodiment of the present invention.

Referring to FIG. 7, the receiving node 120 may perform approximation of the LLR calculation of the decoder.

The complexity of LLR calculation for input to the decoder at the receiving node 120 can be reduced through section division.

First, the LLR equation such as <Equation 3> is approximated by the maximum-log maximum posterior probability estimation method and can be organized as <Equation 9> and <Equation 10>. Additionally, for LLR approximation and complexity calculation, <Equation 9> can be expressed as <Equation 10>.

Approximation of the LLR calculation can be performed by dividing the LLR into the LLR of the first codeword and the LLR of the second codeword. First, the LLR of the first codeword can be divided into sections by symbol decision boundary values for the constellation, and calculated through an equation approximated according to the section to which the received value belongs on the complex plane.

The symbol decision boundary value that divides the section can be set as the median value of the two symbols at the closest distance in the constellation. There are parts of the constellation where the symbols of the constellation become closer due to the bias value. Therefore, the LLR of the first codeword can be considered when the bias value is 1 and when the bias value is other than 1.

If the bias value is 1, 6 symbol decision boundary values and Since 4 out of 6 boundary values overlap, the section can ultimately be divided into 8 boundary values. also top and right of Except for the symbols located at the bottom and left of , the remaining symbols may completely overlap.

If there are received values in 9 sections among overlapping symbols, the LLR value may be 0.

In one embodiment, this is according to each section It can be expressed as <Equation 11>.

here, is half the spacing between symbols in the constellation. It can be. may be a real value representing only the I-signal and Q-signal portions of the received value.

The interval for bias values other than 1 constitutes the constellation. 6 between the symbols, A section divided by six lines into the center of each symbol can be formed between the symbols. Figure 7 shows the section for LLR of the first codeword of 32BQAM with a bias value of 0.8.

All sections are divided into four types according to the location of the received value, and the LLR calculation formula for the first codeword is determined accordingly.

In one embodiment, <Equation 9> is organized into <Equation 12>, and the LLR calculation formula for the received value belonging to each section can be defined as <Equation 13>.

here, represents the value representing the I-signal and Q-signal parts of the received value by moving the area based on the section to which the received value belongs to the origin of the complex plane. is the bias value divided by the average of the total energy of the constellation, It can be.

In one embodiment, the approximation to the second codewords can be summarized as <Equation 14>.

In one embodiment, the LLR calculation approximation made during the decoding process can be compared to XQAM. In the case of dividing the decision interval, the binary search algorithm was used to calculate the complexity, and the complexity was determined by the LLR calculation formulas <Equation 10> and <Equation 12>. and It can be calculated by adding the complexity of .

In one embodiment, the computational complexity was calculated for the operations defined in <Table 3>, and the results are shown in <Table 4>.

The computational complexity of the maximum-log maximum posterior probability estimation method can be compared with that of XQAM and BQAM. In the case of BQAM, both cases where bias is 1 and cases where it is not can be compared. When comparing the total complexity with the maximum-log maximum posterior probability estimation method, it can be seen that the bias of 1.0 was reduced by 97%, and for other biases, it was reduced by 96%. When compared to XQAM, it can be seen that the total complexity decreased by 63% for bias 1.0, and by 46% for other biases.

FIG. 8 is a diagram illustrating a method of operating the transmitting node 110 for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.

Referring to FIG. 8, step S801 is a step of determining system variables including a bias value and modulation order based on the channel state.

Step S803 is a step of determining an odd bit-based constellation using a bias value and a modulation order.

In one embodiment, the modulation order is used to create an even bit-based constellation, e.g. ) is determined, and a first constellation in which the even bit-based constellation is shifted in the positive direction by the bias value (e.g. ) and a second constellation shifted by the bias value in the negative direction (e.g. ), and an odd bit-based constellation (e.g., BQAM) can be determined using the first constellation and the second constellation.

In one embodiment, odd bits may include even bits and the most significant bit (MSB). If the MSB is 0, the symbol may be generated based on the first constellation, and if the MSB is 1, the symbol may be generated based on the second constellation.

Step S805 is a step of generating a symbol by performing modulation based on odd bits using an odd bit-based constellation.

In one embodiment, odd bit-based constellations can be used to map even bits and symbols per MSB.

In one embodiment, information bits are generated based on the modulation order and the block length of the channel code included in the system variable, and the information bits are input to the first bit and the second codeword encoder. Separate into second bits, generate a first codeword from the first bits through a first codeword encoder based on the first code rate included in the system variable, and generate a second code based on the second code rate included in the system variable. Generating a second codeword from the second bit through a coder, interleaving the first codeword according to a first random arrangement having the same length as the first codeword, and generating a second codeword having the same length as the second codeword. 2 The second codeword is interleaved according to a random arrangement, the interleaved first codeword and the second codeword are merged bit by bit to generate a bit stream, and the bit stream is divided into odd bits per odd bit using an odd bit-based constellation. It can be mapped to a symbol.

Step S807 is a step of transmitting the generated symbol to the receiving node 120.

FIG. 9 is a diagram illustrating a method of operating the receiving node 120 for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention.

Referring to FIG. 9, step S901 is a step of receiving a symbol from the transmitting node 110.

Step S903 is a step of decoding the first codeword of the symbol.

In one embodiment, calculating the log-likelihood ratio (LLR) for the first codeword, deinterleaving the LLR for the first codeword according to a first random arrangement having the same length as the first codeword, and , the deinterleaved LLR can be decoded through a first codeword decoder, and the first bit can be generated based on the block length of the channel code.

Step S905 is a step of determining the type of even bit-based constellation according to the most significant bit (MSB) of the decoding result of the first codeword.

In one embodiment, when the MSB of the decoding result of the first codeword is 0, a first constellation is generated by shifting the even bit-based constellation in the positive direction by a bias value, and the decoding result of the first codeword is generated. When the MSB is 1, a second constellation can be generated by shifting the even bit-based constellation by the bias value in the negative direction.

In one embodiment, the first bits may be interleaved according to a first random arrangement having the same length as the first codeword.

Step S907 is a step of decoding the second codeword of the symbol based on the type of even bit-based constellation.

In one embodiment, when the interleaved first bit is 0, the LLR for the second codeword is calculated based on the first constellation in which the even bit-based constellation is shifted in the positive direction by the bias value, and the interleaved When the first bit is 1, the LLR for the second codeword is calculated based on the second constellation in which the even bit-based constellation is shifted by the bias value in the negative direction, and the LLR having the same length as the second codeword is calculated. 2 Deinterleave the LLR for the second codeword according to a random arrangement, decode the deinterleaved LLR through a second codeword decoder, and generate decoded second bits based on the block length and even bits of the channel code. You can.

FIG. 10 is a diagram illustrating another functional configuration of a transmitting node device 1000 for communicating using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention. In one embodiment, the transmitting node device 1000 of FIG. 10 may include the transmitting node 110 of FIG. 1.

Referring to FIG. 10, the transmission node device 1000 may include a control unit 1010, a transmission unit 1020, and a storage unit 1030.

The control unit 1010 determines system variables including a bias value and modulation order based on the channel state, determines an odd bit-based constellation using the bias value and modulation order, and creates an odd bit-based constellation. A symbol can be generated by performing modulation based on odd bits.

In one embodiment, the control unit 1010 may include at least one processor or microprocessor, or may be part of a processor. Additionally, the control unit 1010 may be referred to as a communication processor (CP). The control unit 1010 may control the operation of the transmission node device 1000 according to various embodiments of the present invention.

The transmitter 1020 may transmit the generated symbol to the receiving node 120.

In one embodiment, the transmitter 1020 may include at least one of a wired communication module and a wireless communication module. The receiving unit 1020 may be composed of at least one of a 'transmitting unit', a 'receiving unit', and a 'transceiver'.

The storage unit 1030 can store system variables. In one embodiment, the storage unit 1030 may store information bits. In one embodiment, the storage unit 1030 may store at least one of an even bit-based constellation and an odd bit-based constellation.

In one embodiment, the storage unit 330 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit 330 may provide stored data upon request from the control unit 320.

Referring to FIG. 10, the transmission node device 1000 may include a control unit 1010, a transmission unit 1020, and a storage unit 1030. In various embodiments of the present invention, the transmission node device 1000 may be implemented with more configurations or fewer configurations than the configurations described in FIG. 10 because the configurations described in FIG. 10 are not essential. there is.

FIG. 11 is a diagram illustrating another functional configuration of a receiving node device 1100 for communication using two shifted orthogonal amplitude modulation constellations according to an embodiment of the present invention. In one embodiment, the receiving node device 1100 of FIG. 11 may include the receiving node 120 of FIG. 1.

Referring to FIG. 11, the receiving node device 1100 may include a receiving unit 1110, a control unit 1120, and a storage unit 1130.

The receiving unit 1110 may receive a symbol from the transmitting node 110.

In one embodiment, the receiver 1110 may include at least one of a wired communication module and a wireless communication module. The receiving unit 1110 may be composed of at least one of a ‘transmitting unit’, a ‘receiving unit’, and a ‘transceiver’.

The control unit 1120 decodes the first codeword of the symbol, determines the type of the even bit-based constellation according to the MSB of the decoding result of the first codeword, and determines the type of the even bit-based constellation based on the type of the even bit-based constellation. 2 The codeword can be decoded.

In one embodiment, the control unit 1120 may include at least one processor or microprocessor, or may be part of a processor. Additionally, the control unit 1120 may be referred to as a communication processor (CP). The control unit 1120 may control the operation of the receiving node device 1100 according to various embodiments of the present invention.

The storage unit 1130 can store system variables. In one embodiment, the storage unit 1130 may store at least one of an even bit-based constellation and an odd bit-based constellation.

In one embodiment, the storage unit 1130 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit 1130 may provide stored data upon request from the control unit 1120.

Referring to FIG. 11, the receiving node device 1100 may include a receiving unit 1110, a control unit 1120, and a storage unit 1130. In various embodiments of the present invention, the receiving node device 1100 may be implemented as having more configurations or fewer configurations than the configurations described in FIG. 11 because the configurations described in FIG. 11 are not essential. there is.

The above description is merely an illustrative explanation of the technical idea of the present invention, and those skilled in the art will be able to make various changes and modifications without departing from the essential characteristics of the present invention.

Various embodiments disclosed herein can be performed in any order, simultaneously or separately.

In one embodiment, at least one step may be omitted or added to each drawing described in this specification, may be performed in reverse order, or may be performed simultaneously.

The embodiments disclosed in this specification are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be interpreted in accordance with the claims, and all technical ideas within the equivalent scope should be understood to be included in the scope of rights of the present invention.

100: communication system
110: sending node
120: Receiving node
310: control unit
311: System variable setting unit
312: bit generation unit
313: bit separator
314: First code word encoder
315: Second code word encoder
316: First codeword interleaver
317: Second codeword interleaver
318: Serial Merger
319: BQAM modulator
320: Transmitting unit
510: Receiving unit
520: Control unit
521: First codeword LLR calculator
522: First codeword deinterleaver
523: First codeword decoder
524: First codeword interleaver
525: Second codeword LLR calculator
526: Second codeword deinterlover
527: Second codeword decoder
1000: Transmitting node device
1010: Control unit
1020: Transmitting unit
1030: storage unit
1100: Receiving node device
1110: Receiving unit
1120: Control unit
1130: storage unit

Claims (20)

(a) determining system variables including a bias value and modulation order based on channel conditions;
(b) determining an odd bit-based constellation using the bias value and modulation order;
(c) generating a symbol by performing modulation based on the odd bits using the odd bit-based constellation; and
(d) transmitting the generated symbol to a receiving node;
Including,
Method of operation of a transmitting node for communication using two shifted orthogonal amplitude modulation constellations.
According to paragraph 1,
In step (b),
determining an even bit-based constellation using the modulation order;
determining a first constellation in which the even bit-based constellation is shifted in a positive direction by the bias value and a second constellation in which the even-bit-based constellation is shifted in a negative direction by the bias value; and
determining the odd bit-based constellation using the first constellation and the second constellation;
Including,
Method of operation of a transmitting node for communication using two shifted orthogonal amplitude modulation constellations.
According to paragraph 2,
The odd bits include the even bits and the most significant bit (MSB),
When the MSB is 0, the symbol is generated based on the first constellation,
When the MSB is 1, the symbol is generated based on the second constellation,
Method of operation of a transmitting node for communication using two shifted orthogonal amplitude modulation constellations.
According to paragraph 3,
In step (c),
mapping the symbols per even-numbered bits and MSBs using the odd-bit-based constellation;
Including,
Method of operation of a transmitting node for communication using two shifted orthogonal amplitude modulation constellations.
According to paragraph 1,
In step (c),
generating information bits based on the block length of the modulation order and channel code included in the system variable;
Separating the information bits into first bits input to a first codeword encoder and second bits input to a second codeword encoder;
A first codeword is generated from the first bits through the first codeword encoder based on the first code rate included in the system variable, and the second codeword is based on the second code rate included in the system variable. generating a second codeword from the second bit through an encoder;
Interleaving the first codeword according to a first random arrangement having the same length as the first codeword, and interleaving the second codeword according to a second random arrangement having the same length as the second codeword. step;
generating a bit stream by merging the interleaved first and second codewords bit by bit; and
mapping the generated bit string to the symbol per odd bit using the odd bit-based constellation;
Including,
Method of operation of a transmitting node for communication using two shifted orthogonal amplitude modulation constellations.
(a) receiving a symbol from a transmitting node;
(b) decoding the first codeword of the symbol;
(c) determining the type of even bit-based constellation according to the most significant bit (MSB) of the decoding result of the first codeword; and
(d) decoding the second codeword of the symbol based on the type of the even bit-based constellation;
Including,
Method of operation of a receiving node for communication using two shifted orthogonal amplitude modulation constellations.
According to clause 6,
In step (c),
When the MSB of the decoding result of the first codeword is 0, generating a first constellation by shifting the even bit-based constellation in a positive direction by a bias value; and
When the MSB of the decoding result of the first codeword is 1, generating a second constellation by shifting the even bit-based constellation in a negative direction by the bias value;
Including,
Method of operation of a receiving node for communication using two shifted orthogonal amplitude modulation constellations.
According to clause 6,
In step (b),
calculating a log-likelihood ratio (LLR) for the first codeword;
Deinterleaving the LLR for the first codeword according to a first random arrangement having the same length as the first codeword; and
Decoding the deinterleaved LLR through a first codeword decoder and generating decoded first bits based on the block length of the channel code;
Including,
Method of operation of a receiving node for communication using two shifted orthogonal amplitude modulation constellations.
According to clause 8,
Before step (d) above,
interleaving the first bits according to a first random arrangement having the same length as the first codeword;
Containing more,
Method of operation of a receiving node for communication using two shifted orthogonal amplitude modulation constellations.
According to clause 9,
In step (d),
When the interleaved first bit is 0, the LLR for the second codeword is calculated based on the first constellation in which the even bit-based constellation is shifted by a bias value in the positive direction, and the interleaved first When 1 bit is 1, calculating an LLR for a second codeword based on a second constellation obtained by shifting the even bit-based constellation in a negative direction by a bias value;
Deinterleaving the LLR for the second codeword according to a second random arrangement having the same length as the second codeword; and
Decoding the deinterleaved LLR through a second codeword decoder to generate decoded second bits based on the block length and even number of bits of the channel code;
Including,
Method of operation of a receiving node for communication using two shifted orthogonal amplitude modulation constellations.
Determine system variables including bias value and modulation order based on channel conditions,
Determine an odd bit-based constellation using the bias value and modulation order,
a control unit that generates a symbol by performing modulation based on the odd bits using the odd bit-based constellation; and
a transmitting unit that transmits the generated symbol to a receiving node;
Including,
A transmitting node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 11,
The control unit,
Determine an even bit-based constellation using the modulation order,
Determining a first constellation in which the even bit-based constellation is shifted in a positive direction by the bias value and a second constellation in which the even bit-based constellation is shifted in a negative direction by the bias value,
Determining the odd bit-based constellation using the first constellation and the second constellation,
A transmitting node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 12,
The odd bits include the even bits and the most significant bit (MSB),
When the MSB is 0, the symbol is generated based on the first constellation, and when the MSB is 1, the symbol is generated based on the second constellation.
A transmitting node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 13,
The control unit,
Mapping the symbols per even bit and MSB using the odd bit-based constellation,
A transmitting node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 11,
The control unit,
Generating information bits based on the block length of the modulation order and channel code included in the system variable,
Separating the information bits into a first bit input to a first codeword encoder and a second bit input to a second codeword encoder,
A first codeword is generated from the first bits through the first codeword encoder based on the first code rate included in the system variable, and the second codeword is based on the second code rate included in the system variable. Generating a second codeword from the second bit through an encoder,
Interleaving the first codeword according to a first random arrangement having the same length as the first codeword, and interleaving the second codeword according to a second random arrangement having the same length as the second codeword, and ,
Generating a bit stream by merging the interleaved first codeword and second codeword bit by bit,
Mapping the generated bit string to the symbol per odd bit using the odd bit-based constellation,
A transmitting node device for communicating using two shifted orthogonal amplitude modulation constellations.
A receiving unit that receives a symbol from a transmitting node; and
Decode the first codeword of the symbol,
Determining the type of even bit-based constellation according to the most significant bit (MSB) of the decoding result of the first codeword,
a control unit that decodes the second codeword of the symbol based on the type of the even bit-based constellation;
Including,
A receiving node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 16,
The control unit,
When the MSB of the decoding result of the first codeword is 0, a first constellation is generated by shifting the even bit-based constellation in the positive direction by a bias value,
When the MSB of the decoding result of the first codeword is 1, generating a second constellation in which the even bit-based constellation is shifted in the negative direction by the bias value,
A receiving node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 16,
The control unit,
Calculate the log-likelihood ratio (LLR) for the first codeword,
Deinterleaving the LLR for the first codeword according to a first random arrangement having the same length as the first codeword,
Decoding the deinterleaved LLR through a first codeword decoder to generate a decoded first bit based on the block length of the channel code,
A receiving node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 18,
The control unit,
Interleaving the first bits according to a first random arrangement having the same length as the first codeword,
A receiving node device for communicating using two shifted orthogonal amplitude modulation constellations.
According to clause 19,
The control unit,
When the interleaved first bit is 0, the LLR for the second codeword is calculated based on the first constellation in which the even bit-based constellation is shifted by a bias value in the positive direction, and the interleaved first When 1 bit is 1, the LLR for the second codeword is calculated based on a second constellation in which the even bit-based constellation is shifted in the negative direction by a bias value,
Deinterleaving the LLR for the second codeword according to a second random arrangement having the same length as the second codeword,
Decoding the deinterleaved LLR through a second codeword decoder to generate decoded second bits based on the block length and even bits of the channel code,
A receiving node device for communicating using two shifted orthogonal amplitude modulation constellations.