Synchronous DS-CDMA downlink with frequency selective fading

Author

Weiss, Anthony J. ; Friedlander, Benjamin

Author_Institution

Dept. of Electr. Eng., Tel Aviv Univ., Israel

Volume

47

Issue

1

fYear

1999

fDate

1/1/1999 12:00:00 AM

Firstpage

158

Lastpage

167

Abstract

Synchronous code-division multiple-access (CDMA) techniques possess intrinsic protection against co-channel interference due to the orthogonal spreading codes used. However, in the presence of multipath, the signals lose their orthogonality property, leading to increased cross correlation. In these cases, channel estimation may be needed in order to improve the detection of the desired symbols. We propose a subspace-based algorithm for blind channel estimation of a synchronous CDMA downlink. We compare the channel estimation accuracy with the Cramer-Rao bound, and we show that the estimation accuracy can be increased considerably using a decision feedback approach

Keywords

cochannel interference; code division multiple access; fading channels; feedback; multipath channels; parameter estimation; pseudonoise codes; radio links; signal detection; spread spectrum communication; Cramer-Rao bound; SNR; blind channel estimation; channel estimation accuracy; co-channel interference; code-division multiple-access; cross correlation; decision feedback; frequency selective fading; multipath; orthogonal spreading codes; orthogonality property; signal-to-interference ratio; subspace-based algorithm; symbol detection; synchronous DS-CDMA downlink; Blind equalizers; Channel estimation; Code division multiplexing; Downlink; Fading; Feedback; Frequency; Interchannel interference; Multiaccess communication; Protection;

fLanguage

English

Journal_Title

Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1053-587X

Type

jour

DOI

10.1109/78.738248

Filename

738248