摘要： 在频谱共享环境下,基于译码转发协议和最佳中继选择方案提出一个含有直射信道的两跳中继选择通信系统,并对该系统进行性能分析。系统利用半双工的通信模式,信源及各个中继节点均通过单个天线接收信号,同时在信宿处采用选择性合并技术接收中继链路和直射链路信号。在独立非同一分布的瑞利信道环境下推导中断概率的准确闭合表达式以及高信噪比时的渐进闭合表达式,并利用蒙特卡罗仿真实验对理论分析结果的正确性进行验证。仿真结果表明,得到的表达式可以准确估计通信系统中关键参数对系统端到端性能的影响,高信噪比时更能体现该分析方法的正确性和有效性。

关键词: 频谱共享, 译码转发, 中继选择, 中断概率, 选择性合并, 瑞利衰落

Abstract: A relay selection communication system with direct transmission based on Decode-and-forward(DF) protocol and best relay selection strategy is proposed,also the performance of the system is analyzed under spectrum sharing environment.In this dual-hop cognitive cooperative communication system,all terminals operate in half-duplex mode,source and all the relay nodes are equipped with a single antenna,meanwhile,the Selective Combining(SC) is adopted at the destination to receive signals from direct transmission and relaying link so as to improve the system performance.Both the exact and the high Signal Noise Ratio(SNR) asymptotic closed-form expressions for the Outage Probability(OP) are derived over non-identical Rayleigh fading channels.The correctness of the proposed analysis is corroborated via Monte Carlo simulations.The results show that the expressions derived in this paper can be used to evaluate the impact of the key system parameters on the end-to-end system performance,and high SNR can reflect the correctness and validity of the method better.

Key words: spectrum sharing, Decode-and-forward(DF), relay selection, Outage Probability(OP), Selective Combining(SC), Rayleigh fading

中图分类号: 

• TN929.5