Equivalence of Linear MMSE Detection in DS-CDMA and MC-CDMA
Systems over Time and Frequency Selective Channels

Kadous, Tamer A.; Sayeed, Akbar M.

Journal Menu

EURASIP Journal on Applied Signal Processing
Volume 2002 (2002), Issue 12, Pages 1335-1354
doi:10.1155/S1110865702209099

Equivalence of Linear MMSE Detection in DS-CDMA and MC-CDMA Systems over Time and Frequency Selective Channels

Tamer A. Kadous and Akbar M. Sayeed

Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison 53706, WI, USA

Received 21 January 2002; Revised 14 May 2002

Copyright © 2002 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The goal of this paper is to compare the performance of the linear minimum mean square error (MMSE) detector for a class of code division multiple access (CDMA) systems in time and frequency selective channels. Specifically, we consider direct sequence (DS)-CDMA, multicarrier (MC)-CDMA, and the MC-DS-CDMA systems. Two key tools are used in our development. First, a general time-frequency framework that includes the different CDMA systems as special cases. Second, the duality between time and frequency domains that is used to derive equivalences between the different CDMA systems operating over purely frequency selective and purely time selective channels. We then combine the insights obtained from these special cases to assess the performance of CDMA systems over time and frequency selective channels. We provide sufficient conditions for the codes employed by the CDMA systems for the equivalences to hold. Numerical results are presented to illustrate the results.