Abstract: In this paper, the relay selection problem in the wireless cooperative networks is studied and the buffering capability of relay nodes is enabled. An energy-efficient relay select algorithm with buffer is proposed to prolong the network lifetime and the system throughput is improved. This algorithm takes into account instantaneous channel state information, remaining energy and the queuing states. The best relay for receiving and the best relay for transmitting are selected respectively by different weighting functions. The power allocation between the source node and the relay node is considered to reduce the packet loss rate caused by the difference of channel rate between source node to relay node and relay node to destination. Simulation results show that this algorithm prolongs the network lifetime efficiently and improves network throughput significantly as the number of relays increases and the packet loss rate reduces after considering the power allocation.

Key words: relay selection, network throughput, network lifetime, power allocation

摘要： 研究了无线协作网络中的中继选择问题，允许中继具有缓存数据的能力，提出了一种带有buffer的能量有效性中继选择算法，以延长网络生命周期并提高系统吞吐量。该算法综合考虑链路信息，中继的队列状态以及节点的剩余能量信息，通过加权效用公式选择最优接收数据中继与最优发送数据中继。考虑源节点与中继节点间的功率分配，以降低因源节点到中继节点以及中继节点到目的节点间的信道速率不一致所引起的系统丢包率。仿真实验结果表明，该算法有效地延长了网络的生命周期，随着中继个数的增加网络吞吐量有明显的提高，考虑功率分配后，有效降低了系统丢包率。

关键词: 中继选择, 网络吞吐量, 网络生命周期, 功率分配