@inproceedings{2d789f381aed4f80bcf5b9c62ad20104,
title = "Adaptive time-frequency spreading of quasi-orthogonal block codes for MIMO-OFDM systems",
abstract = "This paper describes a novel low complexity time-frequency spreading of orthogonal block codes for MIMO-OFDM systems in highly time and frequency selective channels. The space-time codes (STC) and space-frequency codes (SFC) proposed in literature for MIMO-OFDM systems require a quasi-static channel, where the channel is assumed to be constant over a number of OFDM time symbols or OFDM subcarriers. In orthogonal block codes (OBC) this is equal to the number of transmit antennas Nt employed. For higher order space-diversity systems with Nt ≥ 4, it is likely that the assumption of constant channel within the OBC to be violated in fast fading channels resulting performance degradation. We propose an adaptive time-frequency spreading strategy that minimizes the decoding error rate in different types of fading channels. The adaptation technique incorporated is based on a fading interference matric, which is evaluated at the transmitter using channel fading statistics. Simulation results demonstrate the effectiveness of the proposed adaptive time-frequency spreading of OBCs.",
author = "Ong, \{J. L.\} and Jayalath, \{A. D.S.\} and Athaudage, \{C. R.N.\}",
year = "2006",
doi = "10.1109/ICCS.2006.301391",
language = "English",
isbn = "1424404118",
series = "2006 IEEE Singapore International Conference on Communication Systems, ICCS 2006",
booktitle = "2006 IEEE Singapore International Conference on Communication Systems, ICCS 2006",
note = "10th IEEE Singapore International Conference on Communications Systems, ICCS 2006 ; Conference date: 30-10-2006 Through 01-11-2006",
}