A Low-Complexity, Full-Rate, Full-Diversity 2 X 2 STBC with Golden Code's Coding Gain

TL;DR

This paper introduces a low-complexity, full-rate, full-diversity 2x2 MIMO space-time block code that achieves the same coding gain as the Golden code, with improved decoding efficiency for certain QAM constellations.

Contribution

The paper proposes a new 2x2 STBC that matches the Golden code's coding gain while reducing decoding complexity for specific QAM constellations.

Findings

Achieves the same coding gain as the Golden code.

Reduces decoding complexity for non-square QAM constellations.

Maintains similar complexity to existing codes for square QAM.

Abstract

This paper presents a low-ML-decoding-complexity, full-rate, full-diversity space-time block code (STBC) for a 2 transmit antenna, 2 receive antenna multiple-input multiple-output (MIMO) system, with coding gain equal to that of the best and well known Golden code for any QAM constellation. Recently, two codes have been proposed (by Paredes, Gershman and Alkhansari and by Sezginer and Sari), which enjoy a lower decoding complexity relative to the Golden code, but have lesser coding gain. The $2\times 2$ STBC presented in this paper has lesser decoding complexity for non-square QAM constellations, compared with that of the Golden code, while having the same decoding complexity for square QAM constellations. Compared with the Paredes-Gershman-Alkhansari and Sezginer-Sari codes, the proposed code has the same decoding complexity for non-rectangular QAM constellations. Simulation results, which compare the codeword error rate (CER) performance, are presented.