Symbol-Level Selective Full-Duplex Relaying with Power and Location Optimization

TL;DR

This paper introduces a symbol-level selective transmission method for full-duplex relaying networks that reduces error propagation, improves spectral efficiency, and outperforms traditional relaying protocols through power and location optimization.

Contribution

It proposes a novel symbol-level selective transmission strategy for FD relays, optimizing power and relay placement to enhance performance without extra signaling overhead.

Findings

Outperforms classic relaying protocols in outage probability and BER.

Optimal power allocation improves performance under strong self-interference.

Relay placement significantly impacts system efficiency.

Abstract

In this paper, a symbol-level selective transmission for full-duplex (FD) relaying networks is proposed to mitigate error propagation effects and improve system spectral efficiency. The idea is to allow the FD relay node to predict the correctly decoded symbols of each frame, based on the generalized square deviation method, and discard the erroneously decoded symbols, resulting in fewer errors being forwarded to the destination node. Using the capability for simultaneous transmission and reception at the FD relay node, our proposed strategy can improve the transmission efficiency without extra cost of signalling overhead. In addition, targeting on the derived expression for outage probability, we compare it with half-duplex (HD) relaying case, and provide the transmission power and relay location optimization strategy to further enhance system performance. The results show that our proposed scheme outperforms the classic relaying protocols, such as cyclic redundancy check based selective decode-and-forward (S-DF) relaying and threshold based S-DF relaying in terms of outage probability and bit-error-rate. Moreover, the performances with optimal power allocation is better than that with equal power allocation, especially when the FD relay node encounters strong self-interference and/or it is close to the destination node.