Abstract
Purchase PDF (163 K)
E-mail Article
Add to my Quick Links
Cited By in Scopus (8)
Purchase PDF (318 K)
doi:10.1016/S0165-1684(02)00452-8 
Copyright © 2002 Elsevier Science B.V. All rights reserved.
Short communication
Constraints in channel shortening equalizer design for DMT-based systems
Received 25 January 2002;
References and further reading may be available for this article. To view references and further reading you must purchase this article.
Abstract
In discrete multitone receivers, a time domain equalizer (TEQ) is used to shorten the channel impulse response, so that the equalized channel impulse response is shorter than the inserted prefix. The aim of this paper is to show that the minimum mean square error (MMSE) channel shortening problem with two different energy constraints, remarkably, lead to the same TEQ coefficients, up to a scaling factor. Moreover, implying the two energy constraints together in the MMSE optimization again yields the same result and comes down to a canonical correlation analysis between the subspace spanned by the transmitted samples and the received samples, respectively. Hence, the TEQ obtained by these three distinct MMSE cases yields the same performance in terms of bit rate. Since the resulting problem can easily be reformulated as a maximization problem, an iterative procedure based on power iterations can be devised to reduce the computational complexity.
Author Keywords: High-speed modems; Time domain equalization (TEQ); Channel shortening
- AT
- transpose of A
- A1/2
- Cholesky factor of A, i.e. A=AT/2A1/2
- J
- cost function
- ek
- zero vector with 1 on the kth position
aJ- gradient of cost function J with respect to a
- expected value
- ||a||2
- Euclidean norm of a
- I
- identity matrix
a
- floor(a)
