Unitary space-time codes perform well at high signal-to-noise ratios on MIMO channels even when the propagation coefficients between transmitter and receiver are unknown. One method of constructing unitary space-time constellations uses a random search to find signal constellations that minimize the maximum pairwise correlation between transmitted signals. The work presented here uses a greedy randomized adaptive search procedure (GRASP) for finding good unitary space-time code constellations. Simulation results show that, on average, this technique finds codes with better correlation properties than the random search method. This new search procedure was also used to find signal constellations with better correlation properties than those previously obtained with the random search technique.

Meeting Name

2005 IEEE Global Telecommunications Conference, GLOBECOM '05 (2005: Nov. 28-Dec. 1, St. Louis, MO)


Electrical and Computer Engineering

Keywords and Phrases

GRASP; MIMO Channels; MIMO Systems; Correlation Methods; Greedy Algorithms; Greedy Randomized Adaptive Search Procedure; Pairwise Correlation; Propagation Coefficients; Radio Networks; Random Search Method; Search Problems; Signal Constellations; Signal-To-Noise Ratios; Space-Time Codes; Unitary Space-Time Codes

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2005 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Nov 2005