Simple Closed-Form Approximations for Achievable Information Rates of Coded Modulation Systems

TL;DR

This paper introduces simple, closed-form approximations for the achievable information rates in coded modulation systems, enabling easier analysis and optimization compared to complex existing expressions.

Contribution

It provides analytically tractable approximations applicable to various constellations, improving system design and understanding over the entire SNR range.

Findings

Approximations are simple and reasonably accurate across SNR range.

They apply to constellations of various sizes, including large ones.

Compared favorably to recent experimental results.

Abstract

The intuitive sphere-packing argument is used to obtain analytically-tractable closed-form approximations for achievable information rates of coded modulation transmission systems, for which only analytically-intractable expressions are available in the literature. These approximations provide a number of insights, possess useful properties and facilitate design/optimization of such systems. They apply to constellations of various cardinalities (including large ones), are simple yet reasonably accurate over the whole signal-to-noise ratio range, and compare favorably to the achieved rates of recent state-of-the art experiments.