认知无线网络中基于最佳中继选择的协作传输策略

Cooperative transmission scheme based on optimal relay selection in cognitive radio network

认知无线网络中在保证主用户数据有效传输的条件下,通过次用户节点间的彼此协作传输,可以有效的提高次用户的数据吞吐能力,从而改善次用户传输性能以满足不同无线业务的通信要求.通过认知无线网络环境,提出了一种基于最佳中继选择的放大转发协作传输方案,并且对所提方案的无冲突传输时间进行了理论分析,给出了非协作和协作传输模式下的无冲突传输时间的解析表达式。数值和仿真实验表明,协作传输的无冲突传输时间明显优于非协作传输,在多个认知中继共存的条件下,基于最佳中继选择方案相对单个中继转发方案所获得的时间增益更加明显,证明了次用户协作为认知无线网络带来可观的性能增益,并随着协作节点数的增大性能得到相应提高。

Transmission performance of secondary users（SUs） in Cognitive Radio Networks（CRNs） can be improved through cooperative transmission between SUs without interfering the regular transmissions of primary users（PUs）.We propose a new AF（Amplify and Forward） cooperative transmission scheme based on optimal relay selection method in CRNs.The analytical expression of non-interference transmission durations is given.Non-cooperative and cooperative schemes are derived,which show the effect of cooperative transmission on non-interference transmission durations performance.Numerical experiments were conducted,which verify the effectiveness of the proposed cooperative transmission scheme and indicate that optimal relay selection cooperation transmission scheme exhibits higher time gains than that of single relaying scheme.The increasing of non-interference transmission durations for cooperative transmission confirms the advantages of our new scheme and moreover,as the number of candidate relays increases the time gain obtained using cooperative transmission scheme increases correspondingly.