TITLE:
A Simplified Improvement on the Design of QO-STBC Based on Hadamard Matrices
AUTHORS:
K. O. O. Anoh, Y. A. S. Dama, R. A. A. Abd-Alhameed, S. M. R. Jones
KEYWORDS:
Hadamard Matrix; QO-STBC; Full Diversity; Multi-Antenna Systems
JOURNAL NAME:
International Journal of Communications, Network and System Sciences,
Vol.7 No.1,
January
20,
2014
ABSTRACT: In this paper, a
simplified approach for implementing QO-STBC is proposed and evaluated with
improved performance. It is based on the Hadamard matrix, in which the scheme
exploits the Hadamard matrix property to attain full diversity. Hadamard matrix has the
characteristic that diagonalizes a quasi-cyclic matrix and consequently, a
decoding matrix so that a diagonal matrix which permits linear decoding is
achieved. Using quasicyclic matrices in designing QO-STBC systems requires that the codes should be rotated to
reasonably separate one code from another such that error floor in the design
can be minimized. It will be shown that, orthogonalizing the secondary codes
and then imposing the Hadamard criteria of the scheme can be well
diagonalized. The results of this simplified approach demonstrate full
diversity and better performance than the interference-free QO-STBC. Results
show about 4 dB gain with respect to the interference-free QO-STBC scheme and it performs alike with the earlier
Hadamard based QO-STBC designed with rotation. These results achieve the
consequent mathematical proposition of the Hadamard matrix and its property is also shown in this study.