Channel-Aware Ordered Successive Relaying with Finite-Blocklength Coding

TL;DR

This paper introduces a channel-aware ordered successive relaying protocol with finite-blocklength coding that enhances spectral efficiency by optimizing relay transmission order and rate, effectively mitigating inter-relay interference.

Contribution

It proposes a novel CAO-SIR-FBC scheme that jointly optimizes relay order and coding rate to recover rate loss in finite-blocklength regimes, outperforming traditional relaying methods.

Findings

CAO-SIR-FBC achieves higher throughput than conventional relaying.

The scheme effectively mitigates inter-relay interference.

Analytical expressions are derived for high SNR regimes.

Abstract

Successive relaying can improve the transmission rate by allowing the source and relays to transmit messages simultaneously, but it may cause severe inter-relay interference (IRI). IRI cancellation schemes have been proposed to mitigate IRI. However, interference cancellation methods have a high risk of error propagation, resulting in a severe transmission rate loss in finite blocklength regimes. Thus, jointly decoding for successive relaying with finite-blocklength coding (FBC) remains a challenge. In this paper, we present an optimized channel-aware ordered successive relaying protocol with finite-blocklength coding (CAO-SIR-FBC), which can recover the rate loss by carefully adapting the relay transmission order and rate. We analyze the average throughput of the CAO-SIR-FBC method, based on which a closed-form expression in a high signal-to-noise regime (SNR) is presented. Average throughput analysis and simulations show that CAO-SIR-FBC outperforms conventional two-timeslot half-duplex relaying in terms of spectral efficiency.