On orthogonal designs and space-time codes

Author

Lu, Hsiao-feng ; Kumar, P. Vijay ; Chung, Habong

Author_Institution

Univ. of Southern California, Los Angeles, CA, USA

Volume

8

Issue

4

fYear

2004

fDate

4/1/2004 12:00:00 AM

Firstpage

220

Lastpage

222

Abstract

Orthogonal-design-based space-time (ODST) codes of size (n×n) offer maximum diversity gain advantage and a simple yet optimal decoding algorithm under an arbitrary signal alphabet or constellation A. However, these designs only exist for n=2, 4, 8 when A is real and for n=2 when A is complex. In this letter, we address the question of the existence of ODST codes of other sizes when A is restricted to be a proper subset of either real or complex numbers. We refer to these as restricted-alphabet ODST (RA-ODST) codes. We show that real RA-ODST codes of size greater than 8 that also guarantee maximum diversity advantage do not exist. Without the diversity requirement, RA-ODST codes exist only when A={a,-a}, 0\n\n\t\t

Keywords

MIMO systems; fading channels; space-time codes; MIMO system; arbitrary signal alphabet; complex number; diversity gain; fading channel; multiple input, multiple output; optimal decoding algorithm; orthogonal design based space-time code; real number; restricted-alphabet ODST; Block codes; Constellation diagram; Decoding; Diversity methods; Information theory; MIMO; Matrix decomposition; Signal processing; Space time codes;

fLanguage

English

Journal_Title

Communications Letters, IEEE

Publisher

ieee

ISSN

1089-7798

Type

jour

DOI

10.1109/LCOMM.2004.825719

Filename

1294930