电力线通信信道下协作非正交多址接入系统的分布式机会中继选择

In this paper, non-orthogonal multiple access (NOMA) technique was applied to downlink multiple-relay cooperative power line communication (PLC) networks. And with considering the fading channel modeled by log-normal distribution and the additive noise modeled by two-state Bernoulli-Gauss, an opportunistic relay selection scheme was proposed. The node order was first designed and power allocation coefficients were adaptively adjusted according to the instantaneous channel state information (ICSI) of the PLC channels. In order to meet the quality of service (QoS) requirements of destination nodes and minimize the system power consumption, the distributed opportunistic relay selection schemes based on the maximum weighted harmonic mean were then respectively designed for decode-and-forward (DF) and amplify-and-forward (AF) protocols. Next, the system outage probability and throughput were analyzed and verified by Monte-Carlo simulations. The results show that the performances of the proposed scheme are better than those of benchmark schemes; compared to our AF scheme, the higher system throughput performance can be achieved by our DF scheme due to its twice power allocation coefficients adjusting. Also, our scheme can be executed in distribution thereby saving the signaling overhead for the ICSI feedback.