Research On Construction Of Polar Code For 5G Mobile Communication System

In the field of channel coding technology,to achieve Shannon limit capacity has always been the goal of communication scholars.Turbo code and LDPC code have been very close to this goal,but it is just close.At present,this goal can only be achieved by polarization coding technology.Polar code is a kind of channel exclusive code and the researching purpose of the construction method for this code is to sort out the channels with capacity approaching to "1".These channels can be used for transmitting information bits after channel polarization.The purpose of decoding algorithm is to restore the information bits in the most accurate way.Firstly,the theory of polarization codes is deeply analyzed and studied in this paper.Then we carefully analyze and introduce the channel polarization phenomena and properties and the process and principle of channel merging and splitting are analyzed in detail.Then the encoding and decoding of polarization codes are analyzed and studied carefully.At present,the research of decoding algorithm is quite mature and universal and the most representative decoding algorithms are successive cancellation decoder(SCD),successive cancellation list decoder(SCLD)and cyclic redundancy check-SCLD(CRC-SCLD).However,research on the construction methods of polarization codes are relatively scarce.Then we compared and studied Monte-Carlo method,Density evolution method and Gauss approximate estimation method in detail.Finally,we go back to the essence of polarization code construction and construct polar codes by designing different kinds of bahattacharry parameters.Then comparing the performance of these parameters and choose the best one as the final candidate to construct polar code and the experiments result show that this method can achieve comparable performance with Gaussian approximate method and it dose not exist the problem of slow polarization rate.Besides,it owns the lowest complexity.