Iterative interference cancellation and decoding using a soft cancellation factor for DS-CDMA

Author

Mostofa, M. ; Howlader, K. ; Woerner, Brian D.

Author_Institution

Bradley Dept. of Electr. & Comput. Eng., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA

Volume

3

fYear

2000

fDate

2000

Firstpage

2076

Abstract

We consider a DS-CDMA system that employs both partial parallel interference cancellation (PIC) and convolutional coding. Information is shared between the operations of interference cancellation and decoding in an iterative manner, using log-likelihood ratios (LLR) of the estimated coded symbols. We investigate the performance of this system for both synchronous and asynchronous CDMA systems, and for both equal and unequal signal powers. Previous work has demonstrated the improved performance of partial parallel interference cancellation in which the interference estimates are weighted by a soft cancellation factor (SCF). We examine the best choice of the SCF for optimizing the combined performance of interference cancellation and coding

Keywords

code division multiple access; convolutional codes; decoding; interference suppression; spread spectrum communication; synchronisation; DS-CDMA; asynchronous CDMA systems; convolutional coding; decoding; estimated coded symbols; iterative interference cancellation; log-likelihood ratios; partial parallel interference cancellation; performance; signal powers; soft cancellation factor; synchronous CDMA systems; Bit error rate; Code division multiplexing; Convolution; Convolutional codes; Error correction codes; Forward error correction; Interference cancellation; Iterative decoding; Multiaccess communication; Signal to noise ratio;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference Proceedings, 2000. VTC 2000-Spring Tokyo. 2000 IEEE 51st

Conference_Location

Tokyo

ISSN

1090-3038

Print_ISBN

0-7803-5718-3

Type

conf

DOI

10.1109/VETECS.2000.851638

Filename

851638