Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Reliability-Latency-Rate Tradeoff in Low-Latency Communications with Finite-Blocklength Coding

Lintao Li, Wei Chen, Petar Popovski, Khaled B. Letaief

TL;DR

This paper investigates the reliability-latency-rate tradeoff in low-latency communication systems with finite-blocklength coding (FBC) and presents the gain-conservation equations to characterize the reliability-latency-rate tradeoffs in low-latency communication systems.

Abstract

Low-latency communication plays an increasingly important role in delay-sensitive applications by ensuring the real-time information exchange. However, due to the constraint on the maximum instantaneous power, guaranteeing bounded latency is challenging. In this paper, we investigate the reliability-latency-rate tradeoff in low-latency communication systems with finite-blocklength coding (FBC). Specifically, we are interested in the fundamental tradeoff between error probability, delay-violation probability (DVP), and service rate. Based on the effective capacity (EC), we present the gain-conservation equations to characterize the reliability-latency-rate tradeoffs in low-latency communication systems. In particular, we investigate the low-latency transmissions over an additive white Gaussian noise (AWGN) channel and a Nakagami-$m$ fading channel. By defining the service rate gain, reliability gain, and real-time gain, we conduct an asymptotic analysis to reveal the fundamental reliability-latency-rate tradeoff of ultra-reliable and low-latency communications in the high signal-to-noise-ratio (SNR) regime. To analytically evaluate and optimize the quality-of-service-constrained throughput of low-latency communication systems adopting FBC, an EC-approximation method is conceived to derive the closed-form expression of that throughput. Our results may offer some insights into the efficient scheduling of low-latency wireless communications, in which statistical latency and reliability metrics are crucial.

Reliability-Latency-Rate Tradeoff in Low-Latency Communications with Finite-Blocklength Coding

TL;DR

This paper investigates the reliability-latency-rate tradeoff in low-latency communication systems with finite-blocklength coding (FBC) and presents the gain-conservation equations to characterize the reliability-latency-rate tradeoffs in low-latency communication systems.

Abstract

Low-latency communication plays an increasingly important role in delay-sensitive applications by ensuring the real-time information exchange. However, due to the constraint on the maximum instantaneous power, guaranteeing bounded latency is challenging. In this paper, we investigate the reliability-latency-rate tradeoff in low-latency communication systems with finite-blocklength coding (FBC). Specifically, we are interested in the fundamental tradeoff between error probability, delay-violation probability (DVP), and service rate. Based on the effective capacity (EC), we present the gain-conservation equations to characterize the reliability-latency-rate tradeoffs in low-latency communication systems. In particular, we investigate the low-latency transmissions over an additive white Gaussian noise (AWGN) channel and a Nakagami- fading channel. By defining the service rate gain, reliability gain, and real-time gain, we conduct an asymptotic analysis to reveal the fundamental reliability-latency-rate tradeoff of ultra-reliable and low-latency communications in the high signal-to-noise-ratio (SNR) regime. To analytically evaluate and optimize the quality-of-service-constrained throughput of low-latency communication systems adopting FBC, an EC-approximation method is conceived to derive the closed-form expression of that throughput. Our results may offer some insights into the efficient scheduling of low-latency wireless communications, in which statistical latency and reliability metrics are crucial.
Paper Structure (45 sections, 162 equations, 8 figures, 1 table)

This paper contains 45 sections, 162 equations, 8 figures, 1 table.

Table of Contents

  1. Introduction
  2. System Model and Main Results
  3. System Model
  4. Effective Bandwidth and Capacity
  5. Main Results
  6. Reliability-latency-rate tradeoff in the finite blocklength regime
  7. High-SNR Slope of EC in the FBL regime
  8. Reliability Gain in the FBL regime
  9. Gain-Conservation Equation for Reliability, Real-time, and Service-Rate Gains
  10. $\epsilon-\chi$ Tradeoff in the AWGN Channel
  11. Effective Capacity Approximation with Normal Approximation
  12. EC Approximation for Fixed-Power Allocation
  13. EC Approximation with Channel-Gain-Based Power Allocation
  14. Numerical Results
  15. Conclusion
  16. ...and 30 more sections

Figures (8)

  • Figure 1: System Model.
  • Figure 2: Structures of Section III and Section IV.
  • Figure 3: Main results for gain-conservation equations and relationships between different quantities.
  • Figure 4: $s_{\infty}$ in the Rayleigh fading channel.
  • Figure 5: $s_{\infty}$ in Rayleigh fading channels with $\kappa=2$.
  • ...and 3 more figures