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arXiv · 0806.3325

On the Search for High-Rate Quasi-Orthogonal Space-Time Block Code

Chau Yuen·Yong Liang Guan·Tjeng Thiang Tjhung
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Abstract

A Quasi-Orthogonal Space-Time Block Code (QO-STBC) is attractive because it achieves higher code rate than Orthogonal STBC and lower decoding complexity than nonorthogonal STBC. In this paper, we first derive the algebraic structure of QO-STBC, then we apply it in a novel graph-based search algorithm to find high-rate QO-STBCs with code rates greater than 1. From the four-antenna codes found using this approach, it is found that the maximum code rate is limited to 5/4 with symbolwise diversity level of four, and 4 with symbolwise diversity level of two. The maximum likelihood decoding of these high-rate QO-STBCs can be performed on two separate sub-groups of symbols. The rate-5/4 codes are the first known QO-STBCs with code rate greater 1 that has full symbolwise diversity level.

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Chau Yuen, Yong Liang Guan, Tjeng Thiang Tjhung. 2008-06-20. On the Search for High-Rate Quasi-Orthogonal Space-Time Block Code. https://arxiv.org/abs/0806.3325

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