Codeword optimization for uplink CDMA dispersive channels

Author

Popescu, Dimitrie C. ; Rose, Christopher

Author_Institution

Dept. of Electr. Eng., Univ. of Texas, San Antonio, TX, USA

Volume

4

Issue

4

fYear

2005

fDate

7/1/2005 12:00:00 AM

Firstpage

1563

Lastpage

1574

Abstract

We present the application of greedy interference avoidance methods to codeword optimization in the uplink of a code division multiple access (CDMA) system in which the channel between a given user and the base station receiver is assumed known and stable for the duration of the transmission. Repeated application of greedy interference avoidance monotonically increases sum capacity and yields an optimal codeword ensemble that satisfies a simultaneous water-filling distribution. However, algorithms for codeword optimization based on the greedy interference avoidance procedure are in general different from water-filling schemes. We illustrate the algorithms with examples and look at properties of optimal codeword ensembles.

Keywords

channel coding; code division multiple access; dispersive channels; greedy algorithms; interference suppression; optimisation; radio links; radio receivers; base station receiver; code division multiple access; codeword adaptation; codeword optimization; greedy interference avoidance method; sum capacity optimization; uplink CDMA dispersive channel; water-filling distribution; Base stations; Design optimization; Dispersion; Intersymbol interference; Modulation coding; Multiaccess communication; OFDM modulation; Optimization methods; Signal design; Transmitters; CDMA; codeword adaptation; distributed interference avoidance; sum capacity optimization;

fLanguage

English

Journal_Title

Wireless Communications, IEEE Transactions on

Publisher

ieee

ISSN

1536-1276

Type

jour

DOI

10.1109/TWC.2005.850351

Filename

1512116