An EM-Based Forward-Backward Kalman Filter for the Estimation of Time-Variant Channels in OFDM

(0000) An EM-Based Forward-Backward Kalman Filter for the Estimation of Time-Variant Channels in OFDM. Signal Processing, IEEE Transactions on [see also Acoustics, Speech, and Signal Processing, IEEE Transactions on], 55.

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Abstract

Orthogonal frequency division multiplexing (OFDM) combines the advantages of high achievable rates and relatively easy implementation. However, for proper recovery of the input, the OFDM receiver needs accurate channel information. In this paper, we propose an expectation-maximization algorithm for joint channel and data recovery in fast fading environments. The algorithm makes a collective use of the data and channel constraints inherent in the communication problem. This comes in contrast to other works which have employed these constraints selectively. The data constraints include pilots, the cyclic prefix, and the finite alphabet restriction, while the channel constraints include sparsity, finite delay spread, and the statistical properties of the channel (frequency and time correlation). The algorithm boils down to a forward-backward Kalman filter. We also suggest a suboptimal modification that is able to track the channel and recover the data with no latency. Simulations show the favorable behavior of both algorithms compared to other channel estimation techniques.

Item Type: Article
Subjects: Computer
Divisions: College Of Engineering Sciences > Electrical Engineering Dept
Depositing User: Mr. Admin Admin
Date Deposited: 24 Jun 2008 16:29
Last Modified: 01 Nov 2019 17:05
URI: http://eprints.kfupm.edu.sa/id/eprint/14261