A Toeplitz displacement method for blind multipath estimation for long code DS/CDMA signals

Author

Escudero, Carlos J. ; Mitra, Urbashi ; Slock, Dirk T M

Author_Institution

Dept. de Electron. y Sistemas, La Coruna Univ., Spain

Volume

49

Issue

3

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

654

Lastpage

665

Abstract

The problem of blind channel identification for direct-sequence/code-division multiple-access (DS/CDMA) multiuser systems is explored. For wideband DS/CDMA signals, multipath distortion is well modeled by a finite-impulse response filter. In this work, a blind channel identification technique based on second-order statistics is investigated. The method exploits knowledge of the spreading code of the user of interest via matched filtering, as well as properties of spreading codes. The current scheme focuses on a method appropriate for randomized long sequence DS/CDMA. This access scheme poses special challenges as the spreading codes are time varying. An analytical approximation of the mean-squared error is derived using perturbation techniques. The performance of the algorithm is studied via simulation and through the mean-squared error approximation, which is observed to be tight

Keywords

FIR filters; Toeplitz matrices; broadband networks; code division multiple access; filtering theory; identification; matched filters; mean square error methods; multipath channels; multiuser channels; random codes; spread spectrum communication; statistical analysis; FIR filter; MSE approximation; Toeplitz displacement method; Toeplitz matrices; analytical approximation; blind channel identification; blind multipath estimation; direct-sequence/code-division multiple-access; finite-impulse response filter; long code DS/CDMA signals; matched filtering; mean-squared error approximation; multipath distortion; multiuser systems; perturbation techniques; randomized codes; randomized long sequence; second-order statistics; simulation; time varying spreading code; wideband DS/CDMA signals; Channel estimation; Conferences; Distortion; Filtering; Matched filters; Multiaccess communication; Perturbation methods; Signal processing; Statistics; Wideband;

fLanguage

English

Journal_Title

Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1053-587X

Type

jour

DOI

10.1109/78.905897

Filename

905897