一种频谱高效的增量中继协议

A Spectrum-Efficient Incremental Relaying Protocol

针对两跳多中继协作传输系统,提出了一种新的高效频谱增量中继协议。该协议通过在目的节点设定接收门限值,判断是否需要中继转发信息。信号传输分两个阶段:第一个阶段,源节点广播信息,当直接传输链路的信噪比高于给定门限时,则传送成功;否则,多个中继节点采用分布式波束成形的方式将信源信号转发给目的节点。进一步,通过理论分析,给出了求解最优门限的解析表达式,通过仿真给出数值解。仿真结果表明,当采用最优门限时,所提出协议的频谱效率在任意信噪比下都优于直接传输和固定中继传输协议。

Aiming at two-hop cooperative transmission system using multiple relays, this paper proposes a novel spectrum-efficient incremental relaying protocol. This protocol, by receiving a predefined threshold at the destination, decides whether the relays are needed. The transmission protocol requires two consecutive phases, in the first phase, the source broadcasts its information to the relays and destination, and when the Signal-to-Noise Ratio （SNR） of the direct transmission exceeds the threshold, signal transmission is ok; otherwise all the relays, with distributed beamforming way, forwards the received signal to the destination. Furthermore, the analytical expression of the optimal threshold is analyzed and derived, and the numerical results are also given through simulation. The simulation results show that the proposed protocol outperforms both direct transmission protocol and fixed relaying transmission protocol in spectral efficiency under any SNR conditions when the optimal threshold is employed.