Reduced Complexity Decoding of n x n Algebraic Space-Time Codes

TL;DR

This paper introduces a recursive decoding algorithm for algebraic space-time codes that significantly reduces the worst-case complexity from exponential to polynomial, enabling more efficient decoding of MIMO channels.

Contribution

A novel recursive decoding algorithm for algebraic space-time codes that lowers complexity from exponential to polynomial in code dimension.

Findings

Reduces decoding complexity from $O(|S|^{n^2})$ to $O(|S|^n)$

Applicable to algebraic space-time codes of arbitrary dimension

Improves practical feasibility of ML decoding for high-dimensional codes

Abstract

Algebraic space-time coding allows for reliable data exchange across fading multiple-input multiple-output channels. A powerful technique for decoding space-time codes in Maximum-Likelihood (ML) decoding, but well-performing and widely-used codes such as the Golden code often suffer from high ML-decoding complexity. In this article, a recursive algorithm for decoding general algebraic space-time codes of arbitrary dimension is proposed, which reduces the worst-case decoding complexity from $O(|S|^{n^2})$ to $O(|S|^n)$.