Channel estimation for DS-CDMA downlink with aperiodic spreading codes

Author

Weiss, Anthony J. ; Friedlander, Benjamin

Author_Institution

Dept. of Electr. Eng. Syst., Tel Aviv Univ., Israel

Volume

47

Issue

10

fYear

1999

fDate

10/1/1999 12:00:00 AM

Firstpage

1561

Lastpage

1569

Abstract

Synchronous code-division multiple-access (CDMA) techniques possess intrinsic protection against cochannel interference when orthogonal spreading codes are used. However, in the presence of multipath propagation, the signals lose their orthogonality property, leading to increased cross correlation. In these cases, channel estimation may be needed in order to improve detection. We propose and compare several algorithms for channel estimation of a synchronous CDMA point-to-multipoint link (downlink) that uses aperiodic spreading waveforms. We compare by simulation and analysis a subspace approach, a pilot-aided approach, and a decision-based approach

Keywords

code division multiple access; codes; estimation theory; land mobile radio; multipath channels; signal detection; spread spectrum communication; synchronisation; DS-CDMA downlink; aperiodic spreading codes; aperiodic spreading waveforms; channel estimation; cochannel interference; cross correlation; decision-based approach; downlink; multipath propagation; orthogonal spreading codes; pilot-aided approach; point-to-multipoint link; subspace approach; synchronous code-division multiple-access; Channel estimation; Code division multiplexing; Downlink; Interchannel interference; Maximum likelihood detection; Maximum likelihood estimation; Multiaccess communication; Performance analysis; Protection; Spread spectrum communication;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.795824

Filename

795824