Research On Polar Modulation Technology Based On Non-Binary Polar Codes

Polar codes is the only channel coding scheme that has been proved theoretically to reach the capacity of binary input discrete memoryless channel.Compared with other channel coding schemes,it has lower bit error rate in the case of short code length.Due to its performance advantages,polar codes has been attracting the attention of researchers and has developed rapidly in recent years.Non-binary polar codes extends the binary input discrete memoryless channel to arbitrary scale,which can also achieve channel polarization,and has the characteristics of faster polarization rate and better performance,which has potential application prospects in the URLLC scenario.In this thesis,the coding and modulation scheme of non-binary polar codes is studied,and the polar coded modulation scheme of non-binary polar codes is improved from two aspects:reducing the bit error rate and reducing the computational complexity.In this thesis,the basic concepts of the non-binary polar codes is introduced,and the encoding and decoding algorithms are explained.The system model of two classical coded modulation schemes BICM and MLC are given,and the advantages of the two schemes are briefly compared,which lays a theoretical foundation for the subsequent research of polar coded modulation scheme of non-binary polar codes.For the BICM scheme,an interleaving design scheme based on diversity effect for non-binary polar codes BIPCM system is proposed in this thesis,which improves the transmission reliability of the BIPCM system.In this thesis,the concept of symbol correlation is proposed by analyzing the encoding process of non-binary polar codes.Furthermore,the diversity effect of non-binary polar codes is analyzed using this concept.Then,based on the diversity effect,a symbol interleaving scheme is proposed,which can reduce the bit error rate by avoiding the simultaneous error of two correlated symbols in a coding block.Based on the above diversity effect and the mapping relationship between the coding symbols and the modulation symbols,a re-interleaving scheme based on non-binary polar codes BIPCM system is proposed,and the diversity gain is obtained by realizing the mutual adaptation of the coding and modulation.Finally,the reliability and complexity of the proposed interleaving scheme are simulated respectively.The simulation results show that the proposed interleaving scheme can reduce the bit error rate under different code lengths and different modulation modes compared with the non-interleaved scheme,and the quaternary polar codes with the same code length has lower decoding complexity compared with the binary polar codes.In order to realize the extremely reliable transmission of information,a non-binary polar coded modulation system based on the traditional MLPCM scheme is proposed,which is called polar modulation system.Polar modulation system is a concatenated coding model,which improves the transmission reliability by secondary coding for some bits.Firstly,the system model of polar modulation is introduced,and the principle of polar modulation system is explained from two aspects of coding and modulation.For the coding module,the concept of useful information is proposed to select some bits into the polar branch.The bits that enter the polar branch carry more useful information,and will undergo a second encoding to improve the anti-interference ability.A bit interleaving scheme is proposed to ensure that the relatively weak bits on the polar branch can also be highly reliable transmission.For the modulation module,a modulation subchannel selection scheme is proposed based on the MLPCM model by using the concept of symbol correlation.In order to verify the high reliability and low time delay of the polar modulation system,the performance of the polar modulation system is simulated from the aspects of bit error rate and computational complexity.The simulation results show that the polar modulation system can effectively reduce the bit error rate compared with the traditional MLPCM system.The polar modulation system also has lower complexity than the traditional MLPCM system.