Research Of Network Coding For Wireless Cooperative Communication System

Wireless communication is pervasive in our daily life. With the increasing demand onwireless communication, how to improve system performance has become the core issue thatresearchers pay close attention to. Wireless cooperative communication is the key techniquein future communication system because it can provide better communication quality, largersystem capacity, broader cover scope, richer services and higher spectrum efficiency. Networkcoding can solve the bottleneck problem in wireless cooperative communication. Throughreasonably joint-design with related communication techniques, network coding can improvesystem performance effectively with simple technical proposal. Based on the wirelesscooperative communication system model, the influence of joint network coding to systemperformance is analyzed in this paper. Moreover simulation results are compared based onsome performance indicators such as system outage probability, bit error rate and systemergodic capacity.Two different network coding forms are used according to two different cooperativecommunication models. First of all, cooperative scheme based on traditional network codingis proposed, and then outage probability and diversity and multiplexing gain are analyzed.Simulation results show that network coding can not only improve system capacity but alsogain lower system outage probability than traditional cooperative scheme, and at the sametime obtains higher diversity and multiplexing gain without increasing hardware cost. Thenasymmetric cooperation scheme based on physical network coding is proposed. The change ofsystem performance is analyzed when the relaying node location changes, in which systemend-to-end bit error rate and ergodic capacity are mainly considered.Secondly, single-relay scheme based on physical network coding is studied undermulti-relay cooperative communication model. Relay selection criterion is proposed andproved to be reasonable through simulation analysis of system outage probability. At last,differential modulation cooperative scheme based on physical network coding is proposed andsuboptimal relay selection criterion is also proposed to simplify the complexity of relayselection. The optimal power allocation of system is analyzed and compared with the equalpower allocation through computer simulation. The simulation result shows the superiority ofthe proposed method.