Performance And Optimization Of Polar Codes Cascading Algorithm

With the advent of the 5G era,an increasing demand for people is the reliability of communications.Polar code is a coding scheme in 5G mobile broadband.Although it is a relatively new channel coding theoretically capable of reaching the Shannon limit and has lower complexity.The polar code performance of translating short and medium code words is inferior to the LDPC code.However,LDPC code has good decoding performance for medium-to-short codewords,instead,it has unavoidable error levels in high SNR regions.Thus,the paper proposes the concept of Polar-Interleave-LDPC(polar code-interleaver-LDPC code)concatenated codes to make polar code have better transmission reliability in real applications.The Polar-Interleave-LDPC concatenated code based on the polar code implement the single-stage serial concatenation of the polar code,the block interleaver,and the LDPC code,for improving the reliability of the polarization code.The main research contents and conclusions are as follows:(1)The implementation of polar code and LDPC code.The encoding and decoding processes of the polar code and the LDPC code are respectively accomplished over the Gaussian white noise channel.In the experiment,the decoding algorithm of polar code is continuous cancellation(SC)decoding algorithm and belief propagation(BP).The results show that the decoding performance and complexity for SC decoding algorithm are more excellent those for BP decoding algorithm.(2)Design and simulation of a concatenation scheme with polar code and LDPC code.During the experiment,if the polar code is directly concatenated with the LDPC code,some continuous errors will inevitably occur in the coding and decoding process.According to the test results of the polar code and the LDPC code,they have no strong error correction ability for continuous error.However,the block interleaver can easily convert continuity error codes into random error codes,not only that,it is also simple to implement and has a small impact on the performance of concatenated codes encoding and decoding.Ultimately,the paper adds the interleaver to the concatenation code project.The prototype becomes the Polar-Interleave-LDPC concatenated code.After the construction,the advantages and feasibility of the interleave pattern should be analyzed;then the specific coding process of will be confirmed;the complexity of the coding time for the experiment is finally deduced.(3)Comparison and analysis of experimental results.The coding and decoding process of the Polar-Interleave-LDPC concatenated code is simulated on the Matlab software by the designing.Under the same conditions of the code length,the code rate,the number of transmitted frames,etc,the polar code,the LDPC code,the Polar-LDPC concatenated code and the Polar-Interleave-LDPC concatenated code are simulated and compared.The experimental results show that the decoding performance of Polar-Interleave-LDPC concatenated codes is superior than others when the SNR is greater than about 1.6dB.The paper discusses the single-level cascading algorithm for the polar code,which settles the foundation for the polar code with the multi-stage cascade algorithm.