SER Analysis for SWIPT-Enabled Differential Decode-and-Forward Relay Networks

TL;DR

This paper analyzes the SER performance of SWIPT-enabled differential relay networks, proposing a near-optimal detector that accurately estimates the optimal power splitting ratio without simulations, and extends analysis to time switching protocols.

Contribution

It introduces a near-optimal linear-complexity detector for SWIPT relay networks and derives an approximate SER expression that enables accurate estimation of the optimal PS ratio.

Findings

Proposed a detector achieving full diversity order.

Derived an approximate SER expression for PS and TS protocols.

Validated effectiveness through simulations.

Abstract

In this paper, we analyze the symbol error rate (SER) performance of the simultaneous wireless information and power transfer (SWIPT) enabled three-node differential decode-and-forward (DDF) relay networks, which adopt the power splitting (PS) protocol at the relay. The use of non-coherent differential modulation eliminates the need for sending training symbols to estimate the instantaneous channel state information (CSI) at all network nodes, and therefore improves the power efficiency, as compared with the coherent modulation. However, performance analysis results are not yet available for the state-of-the-art detectors such as the maximum-likelihood detector (MLD) and approximate MLD. Existing works rely on the Monte-Carlo simulation method to show the existence of an optimal PS ratio that minimizes the overall SER. In this work, we propose a near-optimal detector with linear complexity with respect to the modulation size. We derive an approximate SER expression and prove that the proposed detector achieves the full diversity order. Based on our expression, the optimal PS ratio can be accurately estimated without requiring any Monte-Carlo simulation. We also extend the proposed detector and its SER analysis for adopting the time switching (TS) protocol at the relay. Simulation results verify the effectiveness of our proposed detector and the accuracy of our SER results in various network scenarios for both PS and TS protocols.