Design And Application Of Quasi-cyclic Repeat Accumulate Code In Coding And Cooperation System

With the development of science and technology,modern society increasingly relies on mobile communication technology.Mobile communication technology has also developed vigorously in recent decades.One of the important manifestations is the change in communication methods.Nowadays,people pay more and more attention to the quality of communication services.The most direct manifestation of improving the quality of communication services is to improve the reliability and effectiveness of the system,in which channel coding technology and collaboration technology are very effective measures.Quasi-cyclic Repeat Accumulate(QC-RA)coding cooperation system combines the advantages of the two,not only can obtain the coding gain of QC-RA code,but also can bring diversity gain through cooperation technology.In this paper,we mainly focuse on the joint construction of QC-RA codes and the performance of applying them in collaborative systems.The main work is as follows:(1)The coding cooperation system of QC-RA code is studied.First,the Tanner graph is introduced and the relationship between the Tanner graph and the check matrix is introduced through the Hamming code,and the relationship of the connection between the check node and the variable node of the Tanner graph with the constraint.Then,introduce RA codes,divide RA codes into regular RA codes and Irregular Repeat Accumulate(IRA)codes,and use Tanner diagrams to represent the two types of RA codes,clearly showing the difference between the two.Subsequently,the RA code decoding algorithm is studied.Since the RA code can be decoded as a serial Turbo code,its decoding algorithm can be divided into a bit flipping(BF)decoding algorithm based on checksum statistical iteration.And the probability-based Belif Propagation(BP)iterative decoding algorithm,here we mainly study the BP iterative decoding algorithm and the MS iterative decoding algorithm,and explain the influence of the loop length on the performance of the RA code.Then,the three implementations of the collaboration technology are described,and the principles of the three implementations are explained.Finally,QC-RA code is introduced,the concept of QC-RA code and the construction of QC-RA code based on finite fields are introduced,and the cooperation technology is combined with QC-RA,and the basic model and coding of the QC-RA code coding cooperation system are given.Realize,analyze and derive a point-to-point system model equivalent to the ideal coding collaboration system model.(2)The joint design of QC-RA codes based on tolerances is studied.First,a tolerance-based construction of QC-RA codes is proposed.This structured construction method eliminates the short loops of girth-4 and girth-6 in QC-RA codes and improves the reliability of system transmission of information.Secondly,the working principle of the multi-source and multi-relay coding cooperative system and the realization of the QC-RA code in the cooperative system are studied,and the QC-RA code check matrix used by the source node and the relay node is derived based on the coding realization.,Combined with the collaboration system to derive the equivalent Tanner diagram.Immediately afterwards,the joint design of QC-RA code in the coding cooperation system was studied,and the proposed structured construction method was applied to the coding cooperation system,which theoretically proved that the joint design of the QC-RA code check matrix does not exist inside.girth-4,girth-6 ring.Finally,the BER performance of the QC-RA coding cooperation system based on tolerance structure is numerically simulated.(3)The joint design of QC-RA codes based on the theorem of greatest common divisor is studied.First of all,aiming at the defect of constructing QC-RA codes based on tolerances proposed,we introduce the theorem of greatest common divisor and apply this method to the construction of QC-RA codes.Then,the QC-RA code constructed based on the greatest common divisor is used in the coding cooperation system,and the joint design is carried out.At the same time,it is theoretically proved that there is no short ring of girth-4,girth-6 in the joint check matrix.Finally,the BER performance of the QC-RA code-encoding cooperative system under different conditions is compared in different channel environments.