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. In this system, a selected relay having the highest 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. Approximated expressions of end-to-end (e2e) block error rates (BLERs) are derived over quasi-static Rayleigh fading channels and the finite-blocklength regime. 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. Furthermore, the power allocation and relay location optimization problems are also considered to minimize the asymptotic e2e BLER under the configuration constraints. Our analysis is verified through Monte-Carlo simulations, which yield the system parameters' impact on the system performance.</div>

Short-Packet URLLCs for Multihop MIMO Full-Duplex Relay Networks: Analytical and Deep-Learning-Based Real-Time Evaluation

“…When it comes to SPC in the FBL regime, the error probability is always non-zero, even when the transmission rate is below the Shannon capacity. Given this context, the desired BLER can be alternatively calculated using the achievable rate, blocklength, Shannon capacity, and channel dispersion [15], [24]- [27]. By considering SPC with FBL at hop k, where R k−1 transmits T information bits over a blocklength with β channel uses (CUs) to R k , β needs to remain at least 100 CUs to balance the reliability and latency [28].…”

IoT Short-Packet URLLCs for MIMO Underlay Cognitive Multihop Relaying with Imperfect CSI

“…(16) Because the results from the first-order Riemann and Gauss-Chebyshev quadrature integral approximations are identical, for simplification, we only utilize the first-order Riemann approach to derive the closed-form expression of the asymptotic BLER. By applying (15) and (16) to Proposition 3, the closedform expression for the asymptotic BLER at link k is given by εS,Near k ∼ = F S,Near γ k (θ) . Eventually, similar to (10), the asymptotic E2E BLER for scheme S in the near-CR asymptotic regime is obtained as εS,Near…”

“…Specifically, in [15], the average packet latency, EE, and reliability of uplink EH underlay CR IoT networks were improved by utilizing SPCs in accordance with the uRLLC requirements. [16] investigated SPCs for dual-hop relaying networks, where the system performance was evaluated via the end-to-end (E2E) BLER, latency, and throughput. The optimal PA and RL configurations were also provided in [16].…”

“…[16] investigated SPCs for dual-hop relaying networks, where the system performance was evaluated via the end-to-end (E2E) BLER, latency, and throughput. The optimal PA and RL configurations were also provided in [16]. Makki et al [17] evaluated the E2E latency and throughput of multihop SPCs to support uRLLCs, where either the amplify-and-forward or decode-and-forward (DF) technique was utilized.…”