Dual-hop Relaying Networks for Short-Packet URLLCs: Performance analysis and Optimization

Abstract

<div>This paper investigates short-packet communications for the dual-hop decode-and-forward relaying system to facilitate ultra-reliable and low-latency communications.</div><div>In this system, based on the transmit antenna selection and partial relay selection techniques, a selected relay having the highest received signal-to-noise ratio (SNR) serves as a forwarder to support the unavailable direct link between the source and destination, whereas a maximum ratio combining technique is leveraged at the destination to achieve the highest diversity gain.</div><div>Approximated expressions of end-to-end (e2e) block error rates (BLERs) are derived over quasi-static Rayleigh fading channels and the finite-blocklength regime.</div><div>To gain more insights about the performance behavior in the high-SNR regime, we provide the asymptotic analysis with two approaches, from which the qualitative conclusion based on the diversity order is made.</div><div>Furthermore, the power allocation and relay location optimization problems are also considered to minimize the asymptotic e2e BLER under the configuration constraints.</div><div>Our analysis is verified through Monte-Carlo simulations, which yield the system parameters' impact on the system performance.</div>