Space-Time Codes for Wireless Optical Communications

• Main Authors: Tarokh Vahid, Haas Shane M, Shapiro Jeffrey H
• Format: Article
• Language: English
• Published: SpringerOpen 2002-01-01
• Series: EURASIP Journal on Advances in Signal Processing
• Subjects: space-time codes; optical communication; orthogonal designs
• Online Access: http://dx.doi.org/10.1155/S1110865702000604

<p/> <p>A space-time channel coding technique is presented for overcoming turbulence-induced fading in an atmospheric optical heterodyne communication system that uses multiple transmit and receive apertures. In particular, a design criterion for minimizing the pairwise probability of codeword error in a space-time code (STC) is developed from a central limit theorem approximation. This design criterion maximizes the mean-to-standard-deviation ratio of the received energy difference between codewords. It leads to STCs that are a subset of the previously reported STCs for Rayleigh channels, namely those created from orthogonal designs. This approach also extends to other fading channels with independent, zero-mean path gains. Consequently, for large numbers of transmit and receive antennas, STCs created from orthogonal designs minimize the pairwise codeword error probability for this larger class of fading channels.</p>