| Channel coding technology is one of the essential anti-jamming technologies in modern digital communication system,from 3G to 4G and now to 5g era,Channel coding technology is also improving with the requirements of communication quality and the update of application scenarios.It also brings new opportunities and challenges to the field of blind identification and recognition of channel coding parameters,when the encoding and decoding parameters are unknown,how to identify all kinds of channel coding parameters quickly and accurately is the main research goal of this direction.This thesis focuses on the blind identification algorithm of polar code and turbo code,the main works are summarized as follows:(1)To solve the problem of blind identification for the punctured Turbo code component encoder,this thesis proposes an improved check matrix matching algorithm for this code.Due to the puncturing operation in the encoding process of the Turbo code,the receiver cannot obtain a complete recursive system convolutional code,the traditional blind recognition method is not suitable for the identification of punctured Turbo codes.Therefore,this algorithm has improved the structure of the recognition sequence,for the case where the code words of the Turbo code in the punctured bits is different from the corresponding RSC code,treat these code words as an error code with the same probability of "0" and "1",thereby returing those bits to zero and contrusting appropriate interception sequence to calculate the matching degree,according to the total distribution of the final matching degree,the parameters of punctured turbo code component encoder are identified.(2)To solve the problem of blind identification of polar codes’ parameters,a blind recognition algorithm of polar codes based on zero space matrix matching is proposed.The construction of polar codes’ generation matrix is certain,and all the generation matrices are full rank square matrices,there is no generalized corresponding check matrix in binary field.First delete the rows corresponding to the frozen bit codes by using the channel reliability estimation in the polar code encoding.Then find out the null space matrix of this sub-matrix in the binary field as the check matrix of polar code by using the properties of the generating matrix.Multiply iteratively the code word by the check matrix of different parameters,according to the proportion of "1" in the product result;the code length,number and position distribution of information bits of the code word are determined.In this thesis,the blind estimation methods of polarization code parameters in binary erasure channel and Gaussian white noise channel are both studied and simulated. |
