Open Access

Pilot-Symbol-Assisted Channel Estimation for Space-Time Coded OFDM Systems

EURASIP Journal on Advances in Signal Processing20022002:374703

https://doi.org/10.1155/S111086570200080X

Received: 31 May 2001

Published: 30 May 2002

Abstract

Space-time coded orthogonal frequency division multiplexing (OFDM) transmitter diversity techniques have been shown to provide an efficient means of achieving near optimal diversity gain in frequency-selective fading channels. For these systems, knowledge of the channel parameters is required at the receivers for diversity combining and decoding. In this paper, we propose a low complexity, bandwidth efficient, pilot-symbol-assisted (PSA) channel estimator for multiple transmitter OFDM systems. The pilot symbols are constructed to be nonoverlapping in frequency to allow simultaneous sounding of the multiple channels. The time-varying channel responses are tracked by interpolating a set of estimates obtained through periodically transmitted pilot symbols. Simulations are used to verify the effectiveness of the proposed estimator and to examine its limitations. It is also shown that the PSA channel estimator has a lower computational complexity and better performance than a previously proposed decision-directed minimum mean square error MMSE channel estimator for OFDM transmitter diversity systems.

Keywords

transmitter diversity OFDM channel estimation pilot symbols interpolation

Authors’ Affiliations

(1)
Multimedia Architecture Lab, Motorola Labs
(2)
School of Electrical and Computer Engineering, Georgia Institute of Technology

Copyright

© Lee and Williams 2002