Polar Coded MIMO Relay Cooperation:Code Constructions And Performance Study

With the development of wireless communication,the future communication will develop towards higher speed and higher reliability.The channel coding technique improves the reliability of communication system by obtaining the coding gain.Cooperative communication technology can improve the performance of communication system through spatial diversity.Polar code had been proved theoretically to be able to reach the Shannon limit in binary discrete memoryless channels and have very low encoding and decoding complexity.By combining polar codes with cooperative communication technology,Polar-coded cooperation obtain both channel coding gain and cooperative diversity gain,and it has broad application prospects.In this thesis,we investigate the encoding and decoding technique of polar code,manly investigate implementation and performance of polar-coded cooperation.The main content is as follows:(1)The encoding and the iterative decoding algorithm of Turbo code are described and the code matched interleaver is analyzed.The performance superiority of code matched interleaver is analyzed by simulation.Then encoding and BP decoding algorithm of LDPC code are analyzed.Finally,the advantages and disadvantages of polar code,Turbo code and LDPC code are compared.(2)The encoding of polar code is based on channel polarization.Firstly,the process of channel polarization is analyzed in detail,including channel combining and channel splitting.Secondly,the formation process of polar code's generation matrix and the encoding process of polar code are analyzed.For subchannel selection methods,this paper gives a brief analysis and summary of Bhattacharyya,Gaussian approximation,AWGN channel decision conversion and bit channel entropy four methods.Finally,four Polar code decoding algorithms-SC,BP,SCL and CA-SCL are investigated and their simulation performance on AWGN channel and Rayleigh block fading channel under different conditions are compared.(3)Plotkin construction method of polar code is studied and polar coded cooperation system based on Plotkin construction is proposed.The joint CA-SCL decoding algorithm and the joint SC decoding algorithm on destination are given.Then,the outage probability of the ideal coded cooperation system over the Rayleigh block fading channel is analyzed.Compared with the point-to-point coding system,the simulation show that the outage probability of the coded cooperation system decreases sharply.Finally,the performance of polar coded-cooperation system based on Plotkin construction is analyzed by simulations.Compared with point-to-point coding system and polar coded-cooperation system based on low bit rate Plotkin construction,the coded cooperation system based on Plotkin construction has higher performance.(4)Polar coded-cooperative multiple-input multiple-output(MIMO)based on Plotkin construction where the source and relay have single antenna and the destination is equipped with multiple antennas is proposed.This system can achieve coding gain,cooperation diversity gain and receive multi-antenna gain simultaneously.The scheme of diversity combining at the destination node of the system is given and the outage probability of the coded cooperative MIMO over the Rayleigh block fading channel is analyzed,Compared with the non-cooperative system,the simulation show that the outage probability of the coded cooperative MIMO decreases sharply.The performance of polar coded cooperation MIMO based on Plotkin construction is analyzed by simulations on Rayleigh block fading channel under different conditions.Compared with non-cooperative system and coded cooperation syatem,the coded cooperation MIMO has higher performance.