Channel Coding over Multiple Coherence Blocks with Queueing Constraints

TL;DR

This paper analyzes the performance of wireless systems using finite-blocklength codes over multiple coherence blocks under queueing constraints, deriving bounds and optimizing transmission parameters.

Contribution

It introduces an effective capacity framework incorporating finite-blocklength coding and queueing constraints, providing new insights into optimal transmission strategies.

Findings

Optimal error probability for variable-rate transmission identified

Tradeoff between throughput and coding over multiple blocks characterized

Lower bounds on transmission rate derived using Feinstein's Lemma

Abstract

This paper investigates the performance of wireless systems that employ finite-blocklength channel codes for transmission and operate under queueing constraints in the form of limitations on buffer overflow probabilities. A block fading model, in which fading stays constant in each coherence block and change independently between blocks, is considered. It is assumed that channel coding is performed over multiple coherence blocks. An approximate lower bound on the transmission rate is obtained from Feintein's Lemma. This lower bound is considered as the service rate and is incorporated into the effective capacity formulation, which characterizes the maximum constant arrival rate that can be supported under statistical queuing constraints. Performances of variable-rate and fixed-rate transmissions are studied. The optimum error probability for variable rate transmission and the optimum coding rate for fixed rate transmission are shown to be unique. Moreover, the tradeoff between the throughput and the number of blocks over which channel coding is performed is identified.