A combined soft-decision deinterleaver/decoder for the IS95 reverse link

Author

Earnshaw, A. Mark ; Blostein, Steven D.

Author_Institution

Nortel Networks, Nepean, Ont., Canada

Volume

49

Issue

2

fYear

2000

fDate

3/1/2000 12:00:00 AM

Firstpage

448

Lastpage

456

Abstract

The reverse link encoding steps of the IS95 cellular code-division multiple-access (CDMA) standard consist of convolutional encoding, block interleaving, and orthogonal Walsh function encoding. Deinterleaving individual symbol metrics obtained from the Walsh function matched filters followed by conventional Viterbi decoding produces suboptimal results, as unwanted intersymbol Walsh function correlation is introduced. We propose a combined deinterleaver/decoder with improved performance over existing decoders with little added overhead and no extra decoding delay. Applied to the IS95 reverse link, the proposed decoder has about 1.0-dB gain over soft-decision decoding with interleaved symbol metrics at a bit error rate (BER) of 10^-3

Keywords

Viterbi decoding; Walsh functions; cellular radio; code division multiple access; convolutional codes; error statistics; interleaved codes; matched filters; radio links; BER; CDMA; IS-95 cellular radio standard; Viterbi decoding; bit error rate; block interleaving; code-division multiple-access; combined soft-decision deinterleaver/decoder; convolutional encoding; intersymbol Walsh function correlation; matched filters; orthogonal Walsh function encoding; reverse link; symbol metrics; Bit error rate; Code standards; Convolutional codes; Decoding; Delay; Encoding; Interleaved codes; Matched filters; Multiaccess communication; Viterbi algorithm;

fLanguage

English

Journal_Title

Vehicular Technology, IEEE Transactions on

Publisher

ieee

ISSN

0018-9545

Type

jour

DOI

10.1109/25.832976

Filename

832976