CN110572243B - Cascade system and information transmission method, demodulation and decoding method and device thereof - Google Patents

Cascade system and information transmission method, demodulation and decoding method and device thereof Download PDF

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CN110572243B
CN110572243B CN201910877577.3A CN201910877577A CN110572243B CN 110572243 B CN110572243 B CN 110572243B CN 201910877577 A CN201910877577 A CN 201910877577A CN 110572243 B CN110572243 B CN 110572243B
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information
decoding
demodulation
iteration
sequence
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CN110572243A (en
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姚艳军
张霄
任伟龙
赵飞飞
张正宇
刘孟孟
章仁飞
邹永庆
贺超
刘晨晨
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Tiandi Information Network Research Institute Anhui Co Ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0041—Arrangements at the transmitter end
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0045—Arrangements at the receiver end
    • H04L1/0047—Decoding adapted to other signal detection operation
    • H04L1/005—Iterative decoding, including iteration between signal detection and decoding operation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0056—Systems characterized by the type of code used
    • H04L1/0057—Block codes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0056—Systems characterized by the type of code used
    • H04L1/0064—Concatenated codes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0056—Systems characterized by the type of code used
    • H04L1/0071—Use of interleaving
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/22—Demodulator circuits; Receiver circuits

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Abstract

The invention discloses a cascade system and an information transmission method, a demodulation and decoding method and a device thereof. The cascade system sends the information sequence to LDPC coder to get code word sequence at the sending end, then the code word sequence is modulated by bit interleaving one and 2DPSK modulator; at the receiving end, the received symbol sequence y is sent to an LDPC decoder for decoding after being subjected to multi-symbol differential decomposition of a 2DPSK demodulator and deinterleaving of a deinterleaver, obtained decoded external information is subjected to two-bit interleaving by a bit interleaver and then fed back to the 2DPSK demodulator, information transmission between demodulation and decoding is repeatedly executed, a closed loop structure of demodulation and decoding combined iteration is formed, and after the maximum iteration times of the combined iteration demodulation and decoding are met, the iteration process is stopped and decoding is carried out again, and then judgment output is carried out. The invention provides a demodulation decoding method based on joint iteration aiming at a binary LDPC and 2DPSK cascade system, the method has stable performance, is easy to realize engineering, and can meet the requirements of various platform measurement and control communication in a future access network.

Description

Cascade system and information transmission method, demodulation and decoding method and device thereof
Technical Field
The invention relates to a demodulation decoding technology in the communication field, in particular to a demodulation decoding method based on joint iteration for a binary LDPC and 2DPSK cascade system, and specifically relates to a demodulation decoding method based on joint iteration and a demodulation decoding device thereof.
Background
Differential M-ary phase shift keying (MDPSK) modulation is an important modulation scheme and is widely applied to high-mobility communication such as the internet of vehicles, high-speed trains, unmanned aerial vehicles and the like. Conventional differential detection, referred to as two-symbol differential detection (TSDD), is a common non-coherent detection scheme. However, the performance of TSDD also deteriorates dramatically with increasing modulation order compared to coherent detection. Multi-symbol differential detection (MSDD) for MPSK, which is based on maximum likelihood sequence estimation. To some extent, MSDD can compensate for the gap between TSDD and coherent detection, but the corresponding detection complexity increases exponentially with the length of the sequence. Studies have found that DPSK systems of convolutional and turbo codes can significantly improve the performance of MSDD using iterative receivers.
With the continuous development of communication standards, short frame transmission systems using convolutional codes and turbo codes as concatenated codes have been unable to meet the requirements of high performance and low implementation complexity. Thus, the concatenated codes employed by the system have been converted from convolutional codes and turbo codes to Low Density Parity Check (LDPC) codes. The LDPC code has low implementation complexity and good error correction performance, is easy to realize hardware through full parallel operation, and has low decoding error rate. In the LDPC coding system with the MSDD scheme, the estimation of the channel state information can be avoided by utilizing the external information transmission diagram and adopting the iterative demodulation decoding technology at the receiving end, and the performance of the cascade system can be further improved and the engineering realization complexity can be further reduced.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a demodulation and decoding method based on joint iteration and a demodulation and decoding device thereof, a cascade system aiming at binary LDPC and 2DPSK adopting the demodulation and decoding method, an information transmission method of the cascade system, a computer terminal adopting the demodulation and decoding method and a computer readable storage medium adopting the demodulation and decoding method. The demodulation decoding method based on the joint iteration can adopt the iterative demodulation decoding technology at a receiving end in an LDPC coding system with an MSDD scheme, not only can avoid the estimation of channel state information, but also can improve the performance of a cascade system, so that the performance of the cascade system is stable and the engineering realization is easy.
In order to achieve the purpose, the invention adopts the following technical scheme:
a cascade system of binary LDPC and 2DPSK comprises a sending end, a receiving end and a channel for communication between the sending end and the receiving end; wherein the content of the first and second substances,
setting an LDPC encoder, a bit interleaver I and a 2DPSK modulator at the transmitting end, sending the transmitted information sequence into the LDPC encoder to obtain a code word sequence, and modulating the code word sequence by the bit interleaver I and the 2DPSK modulator;
and a 2DPSK demodulator, a deinterleaver, a bit interleaver II and an LDPC decoder are arranged at the receiving end, a received symbol sequence y is sent to the LDPC decoder for decoding after multi-symbol differential demodulation of the 2DPSK demodulator and deinterleaving of the deinterleaver, the obtained decoded external information is fed back to the 2DPSK demodulator after two-bit interleaving of the bit interleaver, information transmission between demodulation and decoding is repeatedly executed, a closed loop structure of demodulation and decoding joint iteration is formed, and judgment output is carried out after the iterative process is stopped and re-decoding is carried out until the maximum iteration times of joint iteration demodulation and decoding are met.
As a further improvement of the above scheme, the demodulation and decoding method adopted at the receiving end is as follows:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure BDA0002204848970000021
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure BDA0002204848970000022
Making a decision output to obtain
Figure BDA0002204848970000023
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulated posterior information by the symbol sequence y through the 2DPSK demodulator based on a multi-symbol differential detection algorithm
Figure BDA0002204848970000024
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000025
Is composed of
Figure BDA0002204848970000026
(3) Will demodulate a posteriori information
Figure BDA0002204848970000027
And the outer information sequence of the code
Figure BDA0002204848970000028
Differencing to obtain demodulated extrinsic information
Figure BDA0002204848970000029
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000210
Is composed of
Figure BDA00022048489700000211
Is composed of
Figure BDA00022048489700000212
Since q is the first iteration 1, the pair
Figure BDA00022048489700000213
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure BDA00022048489700000214
Obtaining prior information after deinterleaving through the deinterleaver
Figure BDA00022048489700000215
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000216
Is composed of
Figure BDA00022048489700000217
(5) The prior information
Figure BDA00022048489700000218
And obtaining decoding external information through the LDPC decoder based on the normalized minimum sum algorithm
Figure BDA0002204848970000031
And posterior information
Figure BDA0002204848970000032
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000033
Is composed of
Figure BDA0002204848970000034
Is composed of
Figure BDA0002204848970000035
(6) Let q be 2, decodeExternal information
Figure BDA0002204848970000036
Obtaining an out-of-code information sequence after two-bit interleaving through the bit interleaver
Figure BDA0002204848970000037
Since q is 2, therefore
Figure BDA0002204848970000038
Is composed of
Figure BDA0002204848970000039
Therefore, the temperature of the molten steel is controlled,
Figure BDA00022048489700000310
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure BDA00022048489700000311
The invention also provides a demodulation decoding method based on joint iteration, which adopts a mode of joint iteration of demodulation and decoding:
and decoding the received symbol sequence y after multi-symbol differential demodulation and deinterleaving, feeding back the obtained decoded external information after bit interleaving for demodulation, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding combined iteration, stopping the iteration process until the maximum iteration times are met, decoding and judging to output.
As a further improvement of the above scheme, the demodulation and decoding method includes the steps of:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure BDA00022048489700000312
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure BDA00022048489700000313
Making a decision output to obtain
Figure BDA00022048489700000314
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulation posterior information of the symbol sequence y based on a multi-symbol differential detection algorithm
Figure BDA00022048489700000315
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000316
Is composed of
Figure BDA00022048489700000317
(3) Will demodulate a posteriori information
Figure BDA00022048489700000318
And the outer information sequence of the code
Figure BDA00022048489700000319
Differencing to obtain demodulated extrinsic information
Figure BDA00022048489700000320
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000321
Is composed of
Figure BDA00022048489700000322
Is composed of
Figure BDA00022048489700000323
Since q is the first iteration 1, the pair
Figure BDA00022048489700000324
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure BDA00022048489700000325
Obtaining prior information by de-interleaving
Figure BDA00022048489700000326
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000327
Is composed of
Figure BDA00022048489700000328
(5) The prior information
Figure BDA00022048489700000329
The sum symbol sequence y obtains the outer decoding information based on the normalized minimum sum algorithm
Figure BDA00022048489700000330
And posterior information
Figure BDA00022048489700000331
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000332
Is composed of
Figure BDA00022048489700000333
Is composed of
Figure BDA00022048489700000334
(6) Let q be 2, decode the extrinsic information
Figure BDA00022048489700000335
Obtaining the information sequence outside the code after bit interleaving
Figure BDA00022048489700000336
Since q is 2, therefore
Figure BDA00022048489700000337
Is composed of
Figure BDA00022048489700000338
Therefore, the temperature of the molten steel is controlled,
Figure BDA00022048489700000339
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure BDA00022048489700000340
The invention also provides a demodulation decoding device based on joint iteration, which adopts a closed loop structure of joint iteration of demodulation and decoding:
and decoding the received symbol sequence y after multi-symbol differential demodulation and deinterleaving, feeding back the obtained decoded external information after bit interleaving for demodulation, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding combined iteration, stopping the iteration process until the maximum iteration times are met, decoding and judging to output.
As a further improvement of the above solution, the demodulation and decoding apparatus includes:
a joint iteration module for processing q times of iteration data of the symbol sequence y to be demodulated and decoded to obtain posterior information
Figure BDA0002204848970000041
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
a decision module for comparing a posteriori information
Figure BDA0002204848970000042
Making a decision output to obtain
Figure BDA0002204848970000043
Wherein the joint iteration module comprises:
an initialization unit, which is used for setting q to 1 and setting an initial value;
a demodulation extrinsic information unit for obtaining demodulation posterior information of the symbol sequence y based on a multi-symbol differential detection algorithm
Figure BDA0002204848970000044
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000045
Is composed of
Figure BDA0002204848970000046
It is also used to demodulate a posteriori information
Figure BDA0002204848970000047
And the outer information sequence of the code
Figure BDA0002204848970000048
Differencing to obtain demodulated extrinsic information
Figure BDA0002204848970000049
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000410
Is composed of
Figure BDA00022048489700000411
Is composed of
Figure BDA00022048489700000412
Since q is the first iteration 1, the pair
Figure BDA00022048489700000413
Assigning the initial value;
a demodulation outer information deinterleaving unit for deinterleaving the demodulation outer information
Figure BDA00022048489700000414
Obtaining prior information by de-interleaving
Figure BDA00022048489700000415
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000416
Is composed of
Figure BDA00022048489700000417
Calculating a decoding extrinsic information and a posteriori information element for converting the prior information
Figure BDA00022048489700000418
The sum symbol sequence y obtains the outer decoding information based on the normalized minimum sum algorithm
Figure BDA00022048489700000419
And posterior information
Figure BDA00022048489700000420
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000421
Is composed of
Figure BDA00022048489700000422
Is composed of
Figure BDA00022048489700000423
A decoding extrinsic information interleaving unit for making q 2 and interleaving the decoding extrinsic information
Figure BDA00022048489700000424
Obtaining the information sequence outside the code after bit interleaving
Figure BDA00022048489700000425
Since q is 2, therefore
Figure BDA00022048489700000426
Is composed of
Figure BDA00022048489700000427
Therefore, the temperature of the molten steel is controlled,
Figure BDA00022048489700000428
thereby obtaining a reassignment value;
an iteration condition judging unit for repeatedly starting the demodulation external information unit, the demodulation external information deinterleaving unit, the calculation decoding external information and posterior information unit and the decoding external information interleaving unit in sequence until Q is Q to obtain the posterior information
Figure BDA00022048489700000429
The invention also provides an information transmission method of the binary LDPC and 2DPSK cascade system, which comprises the following steps:
setting a sending end;
setting a receiving end;
setting a channel for communication between the sending end and the receiving end;
wherein the content of the first and second substances,
setting an LDPC encoder, a bit interleaver I and a 2DPSK modulator at the transmitting end, sending the transmitted information sequence into the LDPC encoder to obtain a code word sequence, and modulating the code word sequence by the bit interleaver I and the 2DPSK modulator;
and a 2DPSK demodulator, a deinterleaver, a bit interleaver II and an LDPC decoder are arranged at the receiving end, a received symbol sequence y is sent to the LDPC decoder for decoding after multi-symbol differential demodulation of the 2DPSK demodulator and deinterleaving of the deinterleaver, the obtained decoded external information is fed back to the 2DPSK demodulator after two-bit interleaving of the bit interleaver, information transmission between demodulation and decoding is repeatedly executed, a closed loop structure of demodulation and decoding joint iteration is formed, and judgment output is carried out after the iterative process is stopped and re-decoding is carried out until the maximum iteration times of joint iteration demodulation and decoding are met.
As a further improvement of the above scheme, the demodulation and decoding method adopted at the receiving end is as follows:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure BDA0002204848970000051
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure BDA0002204848970000052
Making a decision output to obtain
Figure BDA0002204848970000053
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulated posterior information by the symbol sequence y through the 2DPSK demodulator based on a multi-symbol differential detection algorithm
Figure BDA0002204848970000054
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000055
Is composed of
Figure BDA0002204848970000056
(3) Will demodulate a posteriori information
Figure BDA0002204848970000057
And the outer information sequence of the code
Figure BDA0002204848970000058
Differencing to obtain demodulated extrinsic information
Figure BDA0002204848970000059
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000510
Is composed of
Figure BDA00022048489700000511
Is composed of
Figure BDA00022048489700000512
Since q is the first iteration 1, the pair
Figure BDA00022048489700000513
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure BDA00022048489700000514
Obtaining prior information after deinterleaving through the deinterleaver
Figure BDA00022048489700000515
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000516
Is composed of
Figure BDA00022048489700000517
(5) The prior information
Figure BDA00022048489700000518
And obtaining decoding external information through the LDPC decoder based on the normalized minimum sum algorithm
Figure BDA00022048489700000519
And posterior information
Figure BDA00022048489700000520
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000521
Is composed of
Figure BDA00022048489700000522
Is composed of
Figure BDA00022048489700000523
(6) Let q be 2, decode the extrinsic information
Figure BDA00022048489700000524
Obtaining an out-of-code information sequence after two-bit interleaving through the bit interleaver
Figure BDA00022048489700000525
Since q is 2, therefore
Figure BDA00022048489700000526
Is composed of
Figure BDA00022048489700000527
Therefore, the temperature of the molten steel is controlled,
Figure BDA00022048489700000528
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure BDA00022048489700000529
The invention further provides a computer terminal, which includes a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the demodulation and decoding method based on joint iteration when executing the program.
The present invention also provides a computer readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the steps of the joint iteration based demodulation and decoding method described above.
The binary LDPC and 2DPSK cascade system based on the joint iteration demodulation decoding method not only can obtain excellent error code performance and lower engineering realization complexity, but also can resist larger Doppler frequency offset and phase offset to adapt to a more severe communication environment. Compared with the prior art, the method can ensure that the LDPC code obtains good degree distribution, thereby minimizing the signal-to-noise ratio convergence threshold of a cascade system and improving the performance of the system.
Drawings
Fig. 1 is a functional module schematic diagram of a binary LDPC and 2DPSK cascade system provided in embodiment 1 of the present invention.
Fig. 2 is a signal flow diagram of the demodulation and decoding functions of the cascade system in fig. 1.
Fig. 3 is a flowchart of a demodulation and decoding method based on joint iteration according to embodiment 2 of the present invention.
Fig. 4 is a detailed flowchart of the demodulation and decoding method based on joint iteration in fig. 3.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
Referring to fig. 1, a transmitting end, a receiving end and a channel for communication between the transmitting end and the receiving end of the binary LDPC and 2DPSK cascaded system of the present embodiment. In this embodiment, the channel is AWGN channel 4, and AWGN is an initial word of Additive White Gaussian Noise, which is the most basic Noise and interference model. LDPC refers to low density parity check and 2DPSK refers to binary differential phase shift keying.
And at the transmitting end, an LDPC encoder 1, a bit interleaver I2 and a 2DPSK modulator 3 are arranged, the transmitted information sequence is sent into the LDPC encoder 1 to obtain a code word sequence, and then the code word sequence is modulated by the bit interleaver I2 and the 2DPSK modulator 3.
And at the receiving end, a 2DPSK demodulator 5, a deinterleaver 6, a second bit interleaver 7 and an LDPC decoder 8 are arranged, a received symbol sequence y is sent into the LDPC decoder 8 for decoding after being subjected to multi-symbol difference decomposition of the 2DPSK demodulator 5 and deinterleaving of the deinterleaver 6, obtained decoded external information is subjected to bit interleaving of the second bit interleaver and then fed back into the 2DPSK demodulator 5, information transmission between demodulation and decoding is repeatedly executed, a closed-loop structure of demodulation and decoding joint iteration is formed, and judgment and output after stopping an iteration process and decoding are carried out until the maximum iteration times of joint iteration demodulation and decoding are met.
In this embodiment, at the transmitting end, the transmitted information sequence is sent to the LDPC encoder 1 to obtain a codeword sequence, and then the codeword sequence is subjected to bit interleaving and 2DPSK modulation;
at a receiving end, firstly, a received symbol sequence is sent to an LDPC decoder 8 for decoding after multi-symbol differential demodulation and deinterleaving;
then the obtained decoded external information is fed back to the 2DPSK demodulator 5 after bit interleaving, and information transmission between demodulation and decoding is repeatedly executed;
and finally, stopping the iteration process and decoding and judging and outputting after the maximum iteration times of joint iterative demodulation and decoding are met.
For a demodulation and decoding method based on joint iteration for a binary LDPC and 2DPSK cascaded system, please refer to fig. 2, and a detailed example is described below, the demodulation and decoding method includes the following steps:
(1) an initialization stage, in which the iteration number q is 1 and the prior information
Figure BDA0002204848970000071
The maximum iteration number Q is 3;
(2) in the stage of calculating demodulation extrinsic information, the demodulation prior information obtained after the iteration of the received signal y and the q-1 th time is utilized
Figure BDA0002204848970000072
Obtaining demodulation posterior information based on multi-symbol differential detection algorithm
Figure BDA0002204848970000073
And a decoded extrinsic information sequence
Figure BDA0002204848970000074
Calculating out demodulation external information by difference
Figure BDA0002204848970000075
(3) De-interleaving the demodulated external information
Figure BDA0002204848970000076
Deinterleaved to obtain a priori information sent to the LDPC decoder
Figure BDA0002204848970000077
(4) Calculating decoding external information and posterior information stage, using received signal y and prior information
Figure BDA0002204848970000078
Obtaining outer decoding information based on normalized Minimum Sum Algorithm (MSA)
Figure BDA0002204848970000079
And posterior information
Figure BDA00022048489700000710
(5) Judging an iteration condition stage, enabling the iteration frequency Q to be Q +1, and if p is less than Q, skipping to a decoding outer information interleaving stage; otherwise, the iteration is terminated, and the decoded posterior information is checked
Figure BDA00022048489700000711
Makes a decision and outputs
Figure BDA00022048489700000712
(6) A decoding external information interleaving stage for interleaving the decoding external information
Figure BDA00022048489700000713
Via bit crossingIs obtained after weaving
Figure BDA00022048489700000714
Then sending to multi-symbol difference detector as prior information, and skipping to the stage of calculating out-of-demodulation information.
The demodulation decoding method has stable performance and strong applicability, and is easy for engineering realization. Compared with the prior art, the method can ensure that the LDPC code obtains good degree distribution, thereby minimizing the signal-to-noise ratio convergence threshold of a cascade system and improving the performance of the system.
Example 2
This embodiment 2 introduces a demodulation and decoding method based on joint iteration, where the demodulation and decoding method adopts a joint iteration mode of demodulation and decoding: and decoding the received symbol sequence y after multi-symbol differential demodulation and deinterleaving, feeding back the obtained decoded external information after bit interleaving for demodulation, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding combined iteration, stopping the iteration process until the maximum iteration times are met, decoding and judging to output.
Referring to fig. 3, the demodulation and decoding method includes the following steps:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure BDA0002204848970000081
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure BDA0002204848970000082
Making a decision output to obtain
Figure BDA0002204848970000083
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulation posterior information of the symbol sequence y based on a multi-symbol differential detection algorithm
Figure BDA0002204848970000084
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000085
Is composed of
Figure BDA0002204848970000086
(3) Will demodulate a posteriori information
Figure BDA0002204848970000087
And the outer information sequence of the code
Figure BDA0002204848970000088
Differencing to obtain demodulated extrinsic information
Figure BDA0002204848970000089
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000810
Is composed of
Figure BDA00022048489700000811
Is composed of
Figure BDA00022048489700000812
Since q is the first iteration 1, the pair
Figure BDA00022048489700000813
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure BDA00022048489700000814
Obtaining prior information by de-interleaving
Figure BDA00022048489700000815
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000816
Is composed of
Figure BDA00022048489700000817
(5) The prior information
Figure BDA00022048489700000818
The sum symbol sequence y obtains the outer decoding information based on the normalized minimum sum algorithm
Figure BDA00022048489700000819
And posterior information
Figure BDA00022048489700000820
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000821
Is composed of
Figure BDA00022048489700000822
Is composed of
Figure BDA00022048489700000823
(6) Let q be 2, decode the extrinsic information
Figure BDA00022048489700000824
Obtaining the information sequence outside the code after bit interleaving
Figure BDA00022048489700000825
Since q is 2, therefore
Figure BDA00022048489700000826
Is composed of
Figure BDA00022048489700000827
Therefore, the temperature of the molten steel is controlled,
Figure BDA00022048489700000828
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure BDA00022048489700000829
When the demodulation and decoding method based on joint iteration in this embodiment is applied to the cascade system of the binary LDPC and the 2DPSK in embodiment 1, the demodulation and decoding method adopted at the receiving end is as follows:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure BDA00022048489700000830
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure BDA00022048489700000831
Making a decision output to obtain
Figure BDA00022048489700000832
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulated posterior information by the symbol sequence y through a 2DPSK demodulator 5 based on a multi-symbol differential detection algorithm
Figure BDA0002204848970000091
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000092
Is composed of
Figure BDA0002204848970000093
(3) Will demodulate a posteriori information
Figure BDA0002204848970000094
And the outer information sequence of the code
Figure BDA0002204848970000095
Differencing to obtain demodulated extrinsic information
Figure BDA0002204848970000096
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000097
Is composed of
Figure BDA0002204848970000098
Is composed of
Figure BDA0002204848970000099
Since q is the first iteration 1, the pair
Figure BDA00022048489700000910
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure BDA00022048489700000911
Deinterleaving the data by a deinterleaver 6 to obtain prior information
Figure BDA00022048489700000912
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000913
Is composed of
Figure BDA00022048489700000914
(5) The prior information
Figure BDA00022048489700000915
The sum symbol sequence y is processed by the LDPC decoder 8 based on the normalized minimum sum algorithm to obtain the decoded external information
Figure BDA00022048489700000916
And posterior information
Figure BDA00022048489700000917
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700000918
Is composed of
Figure BDA00022048489700000919
Is composed of
Figure BDA00022048489700000920
(6) Let q be 2, decode the extrinsic information
Figure BDA00022048489700000921
Obtaining an out-of-code information sequence after two 7-bit interleaving through a bit interleaver
Figure BDA00022048489700000922
Since q is 2, therefore
Figure BDA00022048489700000923
Is composed of
Figure BDA00022048489700000924
Therefore, the temperature of the molten steel is controlled,
Figure BDA00022048489700000925
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure BDA00022048489700000926
The demodulation decoding method has stable performance and strong applicability, and is easy for engineering realization. Compared with the prior art, the method can ensure that the LDPC code obtains good degree distribution, thereby minimizing the signal-to-noise ratio convergence threshold of a cascade system and improving the performance of the system.
Example 3
This embodiment introduces a demodulation and decoding apparatus based on joint iteration, which corresponds to the demodulation and decoding method based on joint iteration of embodiment 2, and the demodulation and decoding method can be implemented by using a computer program.
The demodulation decoding device adopts a closed loop structure of demodulation and decoding joint iteration: and decoding the received symbol sequence y after multi-symbol differential demodulation and deinterleaving, feeding back the obtained decoded external information after bit interleaving for demodulation, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding combined iteration, stopping the iteration process until the maximum iteration times are met, decoding and judging to output.
The demodulation decoding device comprises a joint iteration module and a judgment module.
The joint iteration module is used for carrying out q times of iterative data processing on the symbol sequence y to be demodulated and decoded to obtain posterior information
Figure BDA00022048489700000927
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing.
The judgment module is used for comparing the posterior information
Figure BDA00022048489700000928
Making a decision output to obtain
Figure BDA00022048489700000929
The joint iteration module comprises an initialization unit, an external information demodulation and deinterleaving unit, a decoding external information calculation and posterior information unit, an external information decoding and interleaving unit and an iteration condition judgment unit.
The initialization unit is used for setting q to 1 and setting an initial value.
The demodulation external information unit is used for obtaining demodulation posterior information of the symbol sequence y based on a multi-symbol differential detection algorithm
Figure BDA0002204848970000101
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000102
Is composed of
Figure BDA0002204848970000103
It is also used to demodulate a posteriori information
Figure BDA0002204848970000104
And the outer information sequence of the code
Figure BDA0002204848970000105
Differencing to obtain demodulated extrinsic information
Figure BDA0002204848970000106
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA0002204848970000107
Is composed of
Figure BDA0002204848970000108
Is composed of
Figure BDA0002204848970000109
Since q is the first iteration 1, the pair
Figure BDA00022048489700001010
And assigning the initial value.
The demodulation external information de-interleaving unit is used for de-interleaving the demodulation external information
Figure BDA00022048489700001011
Obtaining prior information by de-interleaving
Figure BDA00022048489700001012
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700001013
Is composed of
Figure BDA00022048489700001014
Calculating a decoding extrinsic information and a posteriori information element for using the prior information
Figure BDA00022048489700001015
The sum symbol sequence y obtains the outer decoding information based on the normalized minimum sum algorithm
Figure BDA00022048489700001016
And posterior information
Figure BDA00022048489700001017
Since q is 1, it is not necessary to consider the number of the elements
Figure BDA00022048489700001018
Is composed of
Figure BDA00022048489700001019
Is composed of
Figure BDA00022048489700001020
The outer decoding information interleaving unit is used for making q equal to 2 and converting the outer decoding information into the outer decoding information
Figure BDA00022048489700001021
Obtaining the information sequence outside the code after bit interleaving
Figure BDA00022048489700001022
Since q is 2, therefore
Figure BDA00022048489700001023
Is composed of
Figure BDA00022048489700001024
Therefore, the temperature of the molten steel is controlled,
Figure BDA00022048489700001025
thereby resulting in a reassignment.
The iteration condition judging unit is used for sequentially and repeatedly starting the demodulation extrinsic informationA unit, a demodulation outer information de-interleaving unit, a calculation decoding outer information and posterior information unit, and a decoding outer information interleaving unit until Q is Q to obtain the posterior information
Figure BDA00022048489700001026
This embodiment has the same advantageous effects as embodiment 2.
Example 4
The present embodiments provide a computer terminal comprising a memory, a processor, and a computer program stored on the memory and executable on the processor. The processor implements the steps of the joint iteration-based demodulation and decoding method of embodiment 3 when executing the program.
In the application of the demodulation and decoding method based on joint iteration in embodiment 2, the demodulation and decoding method can be applied in the form of software, for example, a program designed to run independently is installed on a computer terminal, and the computer terminal can be a computer, a smart phone, or the like. Or it can be designed as embedded running program and installed on computer terminal, such as single-chip computer.
Example 5
The present embodiment provides a computer-readable storage medium having a computer program stored thereon. The program, when executed by a processor, implements the steps of the joint iteration-based demodulation and decoding method of embodiment 2.
When the demodulation and decoding method based on joint iteration in embodiment 2 is applied, the demodulation and decoding method can be applied in the form of software, for example, a program designed to be independently run by a computer-readable storage medium, which may be a usb disk, is designed as a usb shield, and is designed to be a program that starts the whole method by external triggering through the usb disk.
The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. A cascade system of binary LDPC and 2DPSK comprises a sending end, a receiving end and a channel for communication between the sending end and the receiving end; it is characterized in that the preparation method is characterized in that,
setting an LDPC encoder, a bit interleaver I and a 2DPSK modulator at the transmitting end, sending the transmitted information sequence into the LDPC encoder to obtain a code word sequence, and then modulating the code word sequence by the bit interleaver I and the 2DPSK modulator;
setting a 2DPSK demodulator, a deinterleaver, a second bit interleaver and an LDPC decoder at the receiving end, sending a received symbol sequence y into the LDPC decoder for decoding after multi-symbol differential demodulation of the 2DPSK demodulator and deinterleaving of the deinterleaver, feeding back obtained decoded external information into the 2DPSK demodulator after two-bit interleaving of the bit interleaver, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding joint iteration, stopping an iteration process and decoding again until the maximum iteration times of joint iteration demodulation and decoding are met, and judging and outputting;
the demodulation decoding method adopted at the receiving end is as follows:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure FDA0002992599210000011
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure FDA0002992599210000012
Making a decision output to obtain
Figure FDA0002992599210000013
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulated posterior information by the symbol sequence y through the 2DPSK demodulator based on a multi-symbol differential detection algorithm
Figure FDA0002992599210000014
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA0002992599210000015
Is composed of
Figure FDA0002992599210000016
(3) Will demodulate a posteriori information
Figure FDA0002992599210000017
And the outer information sequence of the code
Figure FDA0002992599210000018
Differencing to obtain demodulated extrinsic information
Figure FDA0002992599210000019
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000110
Is composed of
Figure FDA00029925992100000111
Figure FDA00029925992100000112
Is composed of
Figure FDA00029925992100000113
Since q is the first iteration 1, the pair
Figure FDA00029925992100000114
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure FDA00029925992100000115
Obtaining prior information after deinterleaving through the deinterleaver
Figure FDA00029925992100000116
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000117
Is composed of
Figure FDA00029925992100000118
(5) The prior information
Figure FDA00029925992100000119
And obtaining decoding external information through the LDPC decoder based on the normalized minimum sum algorithm
Figure FDA00029925992100000120
And posterior information
Figure FDA00029925992100000121
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000122
Is composed of
Figure FDA00029925992100000123
Figure FDA00029925992100000124
Is composed of
Figure FDA00029925992100000125
(6) Let q be 2, decode the extrinsic information
Figure FDA00029925992100000126
Through the stationThe bit interleaver obtains an out-of-code information sequence after two-bit interleaving
Figure FDA0002992599210000021
Since q is 2, therefore
Figure FDA0002992599210000022
Is composed of
Figure FDA0002992599210000023
Therefore, the temperature of the molten steel is controlled,
Figure FDA0002992599210000024
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure FDA0002992599210000025
2. A demodulation decoding method based on joint iteration is characterized in that the demodulation decoding method adopts a mode of joint iteration of demodulation and decoding:
decoding a received symbol sequence y after multi-symbol differential demodulation and deinterleaving, feeding back the obtained decoded external information after bit interleaving for demodulation, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding combined iteration, stopping the iteration process until the maximum iteration times are met, decoding again and judging to output;
the demodulation decoding method comprises the following steps:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure FDA0002992599210000026
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure FDA0002992599210000027
Making a decision output to obtain
Figure FDA0002992599210000028
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulation posterior information of the symbol sequence y based on a multi-symbol differential detection algorithm
Figure FDA0002992599210000029
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000210
Is composed of
Figure FDA00029925992100000211
(3) Will demodulate a posteriori information
Figure FDA00029925992100000212
And the outer information sequence of the code
Figure FDA00029925992100000213
Differencing to obtain demodulated extrinsic information
Figure FDA00029925992100000214
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000215
Is composed of
Figure FDA00029925992100000216
Figure FDA00029925992100000217
Is composed of
Figure FDA00029925992100000218
Since q is the first iteration 1, the pair
Figure FDA00029925992100000219
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure FDA00029925992100000220
Obtaining prior information by de-interleaving
Figure FDA00029925992100000221
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000222
Is composed of
Figure FDA00029925992100000223
(5) The prior information
Figure FDA00029925992100000224
The sum symbol sequence y obtains the outer decoding information based on the normalized minimum sum algorithm
Figure FDA00029925992100000225
And posterior information
Figure FDA00029925992100000226
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000227
Is composed of
Figure FDA00029925992100000228
Figure FDA00029925992100000229
Is composed of
Figure FDA00029925992100000230
(6) Let q be 2, decode the extrinsic information
Figure FDA00029925992100000231
Obtaining the information sequence outside the code after bit interleaving
Figure FDA00029925992100000232
Since q is 2, therefore
Figure FDA00029925992100000233
Is composed of
Figure FDA00029925992100000234
Therefore, the temperature of the molten steel is controlled,
Figure FDA00029925992100000235
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure FDA00029925992100000236
3. A demodulation decoding device based on joint iteration is characterized in that the demodulation decoding device adopts a closed loop structure of joint iteration of demodulation and decoding:
decoding a received symbol sequence y after multi-symbol differential demodulation and deinterleaving, feeding back the obtained decoded external information after bit interleaving for demodulation, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding combined iteration, stopping the iteration process and decoding until the maximum iteration times are met, and judging and outputting output
Wherein, the demodulation decoding device comprises:
a joint iteration module for processing q times of iteration data of the symbol sequence y to be demodulated and decoded to obtain posterior information
Figure FDA0002992599210000031
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
a decision module for comparing a posteriori information
Figure FDA0002992599210000032
Making a decision output to obtain
Figure FDA0002992599210000033
Wherein the joint iteration module comprises:
an initialization unit, which is used for setting q to 1 and setting an initial value;
a demodulation extrinsic information unit for obtaining demodulation posterior information of the symbol sequence y based on a multi-symbol differential detection algorithm
Figure FDA0002992599210000034
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA0002992599210000035
Is composed of
Figure FDA0002992599210000036
It is also used to demodulate a posteriori information
Figure FDA0002992599210000037
And the outer information sequence of the code
Figure FDA0002992599210000038
Differencing to obtain demodulated extrinsic information
Figure FDA0002992599210000039
Due to the fact thatq is 1, therefore
Figure FDA00029925992100000310
Is composed of
Figure FDA00029925992100000311
Figure FDA00029925992100000312
Is composed of
Figure FDA00029925992100000313
Since q is the first iteration 1, the pair
Figure FDA00029925992100000314
Assigning the initial value;
a demodulation outer information deinterleaving unit for deinterleaving the demodulation outer information
Figure FDA00029925992100000315
Obtaining prior information by de-interleaving
Figure FDA00029925992100000316
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000317
Is composed of
Figure FDA00029925992100000318
Calculating a decoding extrinsic information and a posteriori information element for converting the prior information
Figure FDA00029925992100000319
The sum symbol sequence y obtains the outer decoding information based on the normalized minimum sum algorithm
Figure FDA00029925992100000320
And posterior information
Figure FDA00029925992100000321
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000322
Is composed of
Figure FDA00029925992100000323
Figure FDA00029925992100000324
Is composed of
Figure FDA00029925992100000325
A decoding extrinsic information interleaving unit for making q 2 and interleaving the decoding extrinsic information
Figure FDA00029925992100000326
Obtaining the information sequence outside the code after bit interleaving
Figure FDA00029925992100000327
Since q is 2, therefore
Figure FDA00029925992100000328
Is composed of
Figure FDA00029925992100000329
Therefore, the temperature of the molten steel is controlled,
Figure FDA00029925992100000330
thereby obtaining a reassignment value;
an iteration condition judging unit for repeatedly starting the demodulation external information unit, the demodulation external information deinterleaving unit, the calculation decoding external information and posterior information unit and the decoding external information interleaving unit in sequence until Q is Q to obtain the posterior information
Figure FDA00029925992100000331
4. An information transmission method of a cascade system of a binary LDPC and a 2DPSK comprises the following steps:
setting a sending end;
setting a receiving end;
setting a channel for communication between the sending end and the receiving end;
it is characterized in that the preparation method is characterized in that,
setting an LDPC encoder, a bit interleaver I and a 2DPSK modulator at the transmitting end, sending the transmitted information sequence into the LDPC encoder to obtain a code word sequence, and then modulating the code word sequence by the bit interleaver I and the 2DPSK modulator;
setting a 2DPSK demodulator, a deinterleaver, a second bit interleaver and an LDPC decoder at the receiving end, sending a received symbol sequence y into the LDPC decoder for decoding after multi-symbol differential demodulation of the 2DPSK demodulator and deinterleaving of the deinterleaver, feeding back obtained decoded external information into the 2DPSK demodulator after two-bit interleaving of the bit interleaver, repeatedly executing information transmission between demodulation and decoding to form a closed loop structure of demodulation and decoding joint iteration, stopping an iteration process and decoding again until the maximum iteration times of joint iteration demodulation and decoding are met, and judging and outputting;
the demodulation decoding method adopted at the receiving end is as follows:
firstly, carrying out q times of iterative data processing on a symbol sequence y to be demodulated and decoded to obtain posterior information
Figure FDA0002992599210000041
Wherein Q is a positive integer, Q is 1, 2, … …, Q, and Q is the maximum iteration number of the iterative data processing;
second, the posterior information
Figure FDA0002992599210000042
Making a decision output to obtain
Figure FDA0002992599210000043
The iterative data processing method comprises the following steps:
(1) let q be 1 and set an initial value;
(2) obtaining demodulated posterior information by the symbol sequence y through the 2DPSK demodulator based on a multi-symbol differential detection algorithm
Figure FDA0002992599210000044
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA0002992599210000045
Is composed of
Figure FDA0002992599210000046
(3) Will demodulate a posteriori information
Figure FDA0002992599210000047
And the outer information sequence of the code
Figure FDA0002992599210000048
Differencing to obtain demodulated extrinsic information
Figure FDA0002992599210000049
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000410
Is composed of
Figure FDA00029925992100000411
Figure FDA00029925992100000412
Is composed of
Figure FDA00029925992100000413
Since q is the first iteration 1, the pair
Figure FDA00029925992100000414
Assigning the initial value;
(4) will demodulate the extrinsic information
Figure FDA00029925992100000415
Obtaining prior information after deinterleaving through the deinterleaver
Figure FDA00029925992100000416
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000417
Is composed of
Figure FDA00029925992100000418
(5) The prior information
Figure FDA00029925992100000419
And obtaining decoding external information through the LDPC decoder based on the normalized minimum sum algorithm
Figure FDA00029925992100000420
And posterior information
Figure FDA00029925992100000421
Since q is 1, it is not necessary to consider the number of the elements
Figure FDA00029925992100000422
Is composed of
Figure FDA00029925992100000423
Figure FDA00029925992100000424
Is composed of
Figure FDA00029925992100000425
(6) Let q be 2, decode the extrinsic information
Figure FDA00029925992100000426
Obtaining an out-of-code information sequence after two-bit interleaving through the bit interleaver
Figure FDA00029925992100000427
Since q is 2, therefore
Figure FDA00029925992100000428
Is composed of
Figure FDA00029925992100000429
Therefore, the temperature of the molten steel is controlled,
Figure FDA00029925992100000430
thereby obtaining a reassignment value;
(7) repeating steps (2) to (6) until Q ═ Q to obtain the a posteriori information
Figure FDA00029925992100000431
5. A computer terminal comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the joint iteration based demodulation and decoding method according to claim 2 when executing the program.
6. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the joint iteration based demodulation and decoding method according to claim 2.
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Citations (1)

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Family Cites Families (5)

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Publication number Priority date Publication date Assignee Title
CN101841339B (en) * 2009-03-17 2015-05-06 电信科学技术研究院 Encoder, decoder and encoding and decoding methods
JP5299130B2 (en) * 2009-07-03 2013-09-25 富士通セミコンダクター株式会社 Reception data processing circuit and reception data processing switching method
US9191256B2 (en) * 2012-12-03 2015-11-17 Digital PowerRadio, LLC Systems and methods for advanced iterative decoding and channel estimation of concatenated coding systems
ES2633186T3 (en) * 2013-04-03 2017-09-19 Huawei Technologies Co., Ltd. Decoding method, decoding apparatus and communications system
CN106357367A (en) * 2016-07-15 2017-01-25 北京邮电大学 Non-coherent joint detecting and channel decoding method under massive MIMO (multiple input multiple output) system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102064917A (en) * 2011-01-11 2011-05-18 河海大学 Demodulation decoding method for LDPC (Low Density Parity Code) modulation system

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