多中继双向协作转发的分布式实现方案设计及其渐进最优性分析

Design of distributed implementation and performance analysis of asymptotic optimality for cooperative two-way relaying networks

研究了多个双向中继协作传输的分布式实现方案,并给出了其渐进最优性的理论分析。首先,通过高信噪比近似推导出系统均方误差函数的上界,并且利用该上界建立了相应的数学模型;其次,通过矩阵变换和公式推导得到该数学模型的最优解;最后得到相应的分布式实现方案。该方案避免了集中式处理方案中需要"每个中继必须获知整个系统的全部信道信息"这一苛刻条件,而只需要"每个中继获知各自的前后信道信息"就能达到多个双向中继协作转发的效果。所提方案不但避免了集中式处理所需要的中央控制器和很大的反馈开销,而且获得了明显的性能增益。理论分析表明该方案具有渐进最优性。

The realization scheme in the distributed manner was researched for the cooperation transmission of the multi- ple two-way relays, moreover the performance analysis of the asymptotic optimality was also presented. First of all, an upper-bound function was obtained for the true value of the average mean squared error of the whole system by the SNR approximations. Furthermore, a mathematical model was established based on this bound function. Secondly, an optimal solution was obtained for the established problem by using the matrix transform and mathematical derivations. Finally, the realization scheme was obtained in the distributed manner. The proposed scheme avoided the strict requirement that every relay must know the full channel state information （CSI） of the whole networks, while can easily achieve the gain of the relays cooperation by requiting every relay know its local CSI consisted of its forward and backward CSI： Therefore, the proposed scheme not only avoided the central control as required by the central manner and the large amount of the feedback overheads, but also achieved much gain. Theory analysis shows that the proposed scheme is asymptotically optimal.