基于网络编码的感知无线网多中继机制

摘要

多中继感知协作通信技术是无线通信领域中,利用时空分集提升网络吞吐量的热门研究方向.该文首次提出了感知无线网中分布式译码转发后的中继冗余问题,并在理论与仿真上证明了现有传输协议不仅不足以支持多中继感知通信,而且由于其衍生了大量冗余而降低了网络吞吐量.针对该问题,该文提出了在缓存队列中结合随机网络编码的中继机制,从而有效地避免了中继冗余,使得多中继感知的吞吐量接近理想上界,减少缓存空间的占用,仿真结果表明该文提出的机制是一种高效实用的感知中继传输机制.%It is already theoretically presented in previous work that multiple cognitive relay improves the throughput of cognitive networks by increasing diversity in both spatial and temporary domain. According to observation and analysis, huge amounts of redundancies exist when implementing Decode-and-Forward (DF) in a distributed relay network. To solve the issue, a so-called code-assist scheme is proposed in this paper to eliminate redundancies. By such a scheme, network coding is integrated with multiple cognitive relay. It is proved that the achievable throughput of cognitive users approaches to its theoretical upper-bound under the scheme. Moreover,this scheme also helps to decrease the effective buffer size for relay. Simulation results show that the scheme is promising and efficient.