Linear MMSE estimation of time-frequency variant channels for MIMO-OFDM systems

This paper proposes two low-complexity two-dimensional channel estimators forMIMOOFDM systems derived from a joint time–frequency channel estimator. The estimators exploit both time and frequency correlations of the wireless channel via use of Slepianbasis expansions. The computational saving comes from replacing a two-dimensional Slepian-basis expansion with two serially concatenated one-dimensional Slepian-basis expansions. Performance in terms of normalizedmean square error (NMSE) vs. signal-tonoise ratio (SNR) is analyzed via numerical simulations and compared with the original estimator. The analysis of the performance takes into account the impact of both system and channel parameters. The estimators are finally testedwhen usedwithin the loop of an iterative receiver for MIMO-OFDM systems. & 2010 Elsevier B.V. All rights reserved.