Research On Performance Of Multi - Hop Cooperative Diversity System

Nowadays, wireless communication is playing an important role in modern society,and the requirements for communication service quality has risen to unprecedented levels with the increase of demand.But in wireless communication, multipath fading and interference of radio channel itself has always been the bottleneck of affecting the transmission rate and quality, and now cooperative diversity is considered to be the simplest and the most effective technology to solve the problem.In cooperative diversity communication network,the transmission performance between each node is becoming a hot spot of concern,and the important indicator we should consider is the interruption performance when we study transmission performance.The outage performance of multi-hop DF,SDF cooperative diversity system is introduced in this paper.We build a multi-hop cooperative diversity system model,and the outage performance and diversity of multi-hop DF diversity system are respectively derived, simulation analysis derive the approximate expression of the outage probability.We find that multi-hop diversity system can not provide full space diversity,and an improved SDF algorithm is proposed to solve this shortage.The message will be resent if the system determines that the relay node can not correctly decode and forward or it is lower than the present threshold.In the same multi-hop cooperative diversity system, outage probability expression and diversity of multi-hop SDF diversity system are respectively proposed under the condition of high SNR. Theoretical analysis and simulation results show that the improved SDF can improve the transmission performance and get a good diversity gain.