In this paper, we investigate the impact of fading channel correlation on the performance of dual-hop decode-and-forward (DF) simultaneous wireless information and power transfer (SWIPT) relay networks. More specifically, by considering the power splitting-based relaying (PSR) protocol for the energy harvesting (EH) process, we quantify the effect of positive and negative dependency between the source-to-relay (SR) and relay-to-destination (RD) links on key performance metrics such as ergodic capacity and outage probability. To this end, we first represent general formulations for the cumulative distribution function (CDF) of the product of two arbitrary random variables, exploiting copula theory. This is used to derive the closed-form expressions of the ergodic capacity and outage probability in a SWIPT relay network under correlated Nakagami-m fading channels. Monte-Carlo (MC) simulation results are provided throughout to validate the correctness of the developed analytical results, showing that the system performance significantly improves under positive dependence in the SR-RD links, compared to the case of negative dependence and independent links. Results further demonstrate that the efficiency of the ergodic capacity and outage probability ameliorates as the fading severity reduces for the PSR protocol.

翻译：本文研究了衰落信道相关性对双跳解码转发（DF）同步无线信息与能量传输（SWIPT）中继网络性能的影响。具体而言，通过考虑基于功率分配的中继（PSR）协议用于能量收集（EH）过程，我们量化了源到中继（SR）链路与中继到目的节点（RD）链路之间的正负依赖关系对遍历容量和中断概率等关键性能指标的影响。为此，我们首先利用copula理论给出了两个任意随机变量乘积的累积分布函数（CDF）的一般表达式。这用于推导相关Nakagami-m衰落信道下SWIPT中继网络中遍历容量和中断概率的闭式表达式。全文提供了蒙特卡洛（MC）仿真结果，以验证所开发分析结果的正确性，表明与负依赖和独立链路情况相比，在SR-RD链路正依赖下系统性能显著提升。结果进一步表明，随着PSR协议衰落严重程度的降低，遍历容量和中断概率的效率得到改善。