Comments on "Partial parallel interference cancellation for CDMA"

Author

Buehrer, R. Michael ; Nicoloso, Steven P.

Author_Institution

Lucent Technol., Bell Labs., Whippany, NJ, USA

Volume

47

Issue

5

fYear

1999

fDate

5/1/1999 12:00:00 AM

Firstpage

658

Lastpage

661

Abstract

We comment on partial parallel interference cancellation as discussed in the paper by Divsalar et al. (see ibid. vol.46, p.258-68, 1998). The aforementioned work showed that by multiplying the symbol estimates by a factor less than unity in the early stages of cancellation, the performance of parallel cancellation can be improved relative to full ("brute force") cancellation. In this paper we analyze the improvement of parallel cancellation when using partial cancellation, and provide additional insight into the gains. Specifically, we show that the decision statistic is biased when linear (soft) estimates of the symbol or channel are used for cancellation. Partial cancellation improves the performance in this case by reducing the decision statistic bias.

Keywords

code division multiple access; decision theory; interference suppression; phase shift keying; statistical analysis; BPSK; CDMA; brute force cancellation; decision statistic bias reduction; linear estimates; partial parallel interference cancellation; performance; soft estimates; symbol estimates; Binary phase shift keying; Bit error rate; Correlators; Interference cancellation; Matched filters; Multiaccess communication; Multiuser detection; Performance gain; Phase estimation; Statistics;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.768754

Filename

768754