A New Low-Complexity Decodable Rate-1 Full-Diversity 4 x 4 STBC with Nonvanishing Determinants

TL;DR

This paper introduces a new 4x4 space-time block code that offers full diversity, low decoding complexity, and non-vanishing determinants, improving performance and PAPR over existing codes in wireless channels.

Contribution

The paper proposes a novel low-complexity decodable 4x4 STBC with full diversity and NVD property, enhancing performance and reducing PAPR compared to prior codes.

Findings

Achieves the best performance among compared codes.

Has the smallest PAPR at the same constellation.

Slight increase in detection complexity for high-order QAM.

Abstract

Space-time coding techniques have become common-place in wireless communication standards as they provide an effective way to mitigate the fading phenomena inherent in wireless channels. However, the use of Space-Time Block Codes (STBCs) increases significantly the optimal detection complexity at the receiver unless the low complexity decodability property is taken into consideration in the STBC design. In this letter we propose a new low-complexity decodable rate-1 full-diversity 4 x 4 STBC. We provide an analytical proof that the proposed code has the Non-Vanishing-Determinant (NVD) property, a property that can be exploited through the use of adaptive modulation which changes the transmission rate according to the wireless channel quality. We compare the proposed code to existing low-complexity decodable rate-1 full-diversity 4 x 4 STBCs in terms of performance over quasi-static Rayleigh fading channels, detection complexity and Peak-to-Average Power Ratio (PAPR). Our code is found to provide the best performance and the smallest PAPR which is that of the used QAM constellation at the expense of a slight increase in detection complexity w.r.t. certain previous codes but this will only penalize the proposed code for high-order QAM constellations.