A new look at digital orthogonal transmultiplexers for CDMA communications

Author

Akansu, Ali N. ; Tazebay, M.V. ; Haddad, Richard A.

Author_Institution

Dept. of Electr. & Comput. Eng., New Jersey Inst. of Technol., Newark, NJ, USA

Volume

45

Issue

1

fYear

1997

fDate

1/1/1997 12:00:00 AM

Firstpage

263

Lastpage

267

Abstract

Orthogonal transmultiplexers have been successfully utilized for multiuser communications. They are of the FDMA type in their most common version. The transmultiplexers using frequency selective PR-QMFs as their user codes were reported in the literature. This approach conflicts with the requirements of a CDMA communications system. We introduce novel spread spectrum PR-QMF codes, wherein the orthogonality is distributed over both time and frequency domains. It is shown that the proposed multivalued spread spectrum PR-QMF codes with minimized auto and cross-correlation properties outperform the conventional binary Gold codes in CDMA communication scenarios considered in the article

Keywords

FIR filters; band-pass filters; binary sequences; code division multiple access; convolutional codes; correlation methods; digital radio; filtering theory; quadrature mirror filters; signal reconstruction; spread spectrum communication; telecommunication channels; transmultiplexing; CDMA communications; FDMA; autocorrelation properties; conventional binary Gold codes; cross-correlation properties; digital orthogonal transmultiplexers; frequency domain; multiuser communications; multivalued spread spectrum PR-QMF codes; perfect reconstruction FIR QMF banks; spread spectrum communications; time domain; user codes; Communication systems; Delay; Filter bank; Finite impulse response filter; Frequency division multiaccess; Frequency division multiplexing; Frequency domain analysis; Gold; Multiaccess communication; Spread spectrum communication;

fLanguage

English

Journal_Title

Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1053-587X

Type

jour

DOI

10.1109/78.552227

Filename

552227