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Structured channel estimation based decision feedback equalizers for sparse multipath channels with applications to digital TV receivers | IEEE Conference Publication | IEEE Xplore

Structured channel estimation based decision feedback equalizers for sparse multipath channels with applications to digital TV receivers


Abstract:

In this paper, we investigate the performance of channel estimation based equalizers. We introduce two different channel estimation algorithms. Our first channel estimati...Show More

Abstract:

In this paper, we investigate the performance of channel estimation based equalizers. We introduce two different channel estimation algorithms. Our first channel estimation scheme is a novel structured channel impulse response (CIR) estimation method for sparse multipath channels. The novel CIR estimation method was called blended least squares (BLS) which uses symbol rate sampled signals, based on blending the least squares based channel estimation and the correlation and thresholding based channel estimation methods. The second CIR estimation is called Variable thresholding (VT), and is based on improving the output of the correlation and thresholding based channel estimation method. We then use these two CIR estimates to calculate the decision feedback equalizer (DFE) tap weights. Simulation examples are drawn from the ATSC digital TV 8-VSB system. The delay spread for digital TV systems can be as long as several hundred times the symbol duration; however, digital TV channels are, in general, sparse where there are only a few dominant multipaths.
Date of Conference: 03-06 November 2002
Date Added to IEEE Xplore: 07 May 2003
Print ISBN:0-7803-7576-9
Print ISSN: 1058-6393
Conference Location: Pacific Grove, CA, USA

1 Overview of Data Transmission Model

For the communications systems utilizing periodically transmitted training sequence, least-squares (LS) based channel estimation or the correlation based channel estimation algorithms have been the most widely used two alternatives. Both methods use a stored copy of the known transmitted training sequence at the receiver. The properties and the length of the training sequence are generally different depending on the particular communication system's standard specifications. In the sequel, although the examples following the derivations of the blended channel estimator will be drawn from the ATSC digital TV 8-VSB system [1], to the best of our knowledge it could be applied with minor modifications to any digital communication system with linear modulation which employs a training sequence.

References

References is not available for this document.