Research On Rate Compatible Adaptive Polar Coding Cooperation Technology

In order to meet the transmission needs of multimedia services,a wireless communication network with large capacity,high speed and high reliability is urgently needed.Channel coding technology can resist all kinds of interference when data is transmitted in the channel,and improve the efficiency of data transmission and system reliability.Polar code is adopted as the control channel coding for the 5G e MBB scene,which is the only known channel coding technology that can "reach" Shannon's capacity.Cooperative communication is a virtual multiple input multiple output(virtual quasi MIMO)technology that can resist channel fading and obtain spatial diversity gain,which can also improve the capacity and reliability of the system and reduce the complexity of the equipment.The combination of channel coding technology and cooperative communication technology can obtain both coding gain and diversity gain.The main innovations are as follows:In order to solve the problem that the original polar code length can't be adaptive,this paper proposes a new scheme for shortening the polar codes of the system,which can keep the polarization characteristics of the polar code to the maximum extent and further improve the bit error rate(BER)performance of the system.Simulation results show that in the AWGN channel,under the condition of high code rate,the performance of the BER of the proposed method is better than both the punctured system Polar code and the shortened Polar code.When the code rate is 3/4 and the BER is 10-4,the proposed method can obtain a gain of about 0.5 d B than the shortened Polar code,and a gain of about 0.25 d B than the punctured system Polar code.In order to solve the transmission problem of rate code length adaptive polar code in cooperative communication,two schemes are proposed: the coding cooperation with shortened polar code and the coding cooperation with system polar code shortened.These two schemes are based on the Plotkin structure of polar code to realize the coding cooperation of rate code length adaptive polar code.Both schemes can effectively improve the transmission rate and reliability of the system,while preserving the low complexity coding and decoding characteristics of cooperative communication.The simulation results show that under asymmetric and symmetric conditions,the BER performance of the system with shortened system polar code is significantly higher than that with shortened polar code,but the block error rate performance is basically the same.