Research On Transmission Performance In Wireless Distributed Cooperative Relay Communication Network

With the rapid development of wireless communication technology, the future of the most important characteristics of public land mobile communication system is in a large covered area and high-speed mobile environment support greater system capacity and higher rate of business data, the focus of the wireless communication service has turned to need broad spectrum and high transmission rate of multimedia communication, etc. MIMO technology cooperation and communication technology to improve the transmission rate and reliability of communication system of these two major advantages make them attention.Compared with MIMO technology, cooperative communication technology means, under the condition of equipment can only be equipped with an antenna, antenna can share other idle equipment, so as to realize the virtual MIMO technique. The technology for wireless communication system provides diversity gain and multiplexing gain, thus improve the performance of the system.In this paper, a distributed cooperative communication system, because in the next generation of mobile communication system, antenna technology and relay technology become more critical technology, and has been further promotion and application. This distributed cooperative communication system is as follows:the main point of the source node and relay node cooperation and the decoding forwarding agreement will signal is sent to the destination node.This article focuses on the single relay cooperative scheme under the network environment and the transmission performance of the system. Analyses the channel model and the power set limit under the condition of system performance, and carries on the data of simulation by Matlab software, and verification are given. Then the article presents a new channel model, and puts forward a new power constraints, make it more in line with the actual transmission environment. This new channel model is a hybrid channel model, namely:the source-relay link is modeled as a rice fading channel, and the source+relay-target link for Rayleigh fading channel, thus forming a les mixed Rayleigh channel. In addition, also studied the new power constraints. At last, through Matlab simulation curve analysis of the data in the improved channel model and power limit under the condition of system transmission performance. But the analysis is based on relay nodes can decode information correctly, and then resend the message, on the basis of the actual channel transmission, relay can’t always be decode correctly, so this paper proposes a adaptive communication protocols, can better analysis of the transmission performance of the system.