Bound on mutual information for DS-CDMA spreading over independent fading channels

Author

Médard, Muriel

Author_Institution

Lincoln Lab., MIT, Lexington, MA, USA

Volume

1

fYear

1997

fDate

2-5 Nov. 1997

Firstpage

187

Abstract

We consider using DS-CDMA over channels which decorrelate in frequency. We allow the bandwidth to increase while maintaining a fixed total average power. The bandwidth over which we transmit is divided into several slices, each of which has its own spreading sequence. We show that for a large bandwidth DS-CDMA spreading is not advantageous when the channel truly decorrelates in frequency or when the channel bandwidth slices are correlated but not jointly estimated.

Keywords

Gaussian processes; Markov processes; correlation methods; fading; pseudonoise codes; spread spectrum communication; time-varying channels; DS-CDMA; Gauss-Markov model; bandwidth scaled spreading method; correlated channel bandwidth slices; decorrelation; independent fading channels; mutual information bound; spreading sequence; time varying channel; total average power; Bandwidth; Channel capacity; Decorrelation; Fading; Frequency; Laboratories; Multiaccess communication; Mutual information; Semiconductor device measurement; Time measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Signals, Systems & Computers, 1997. Conference Record of the Thirty-First Asilomar Conference on

Conference_Location

Pacific Grove, CA, USA

ISSN

1058-6393

Print_ISBN

0-8186-8316-3

Type

conf

DOI

10.1109/ACSSC.1997.680053

Filename

680053