Title :
A composite cyclodespreader and semiblind beamformer for WCDMA
Author :
Wei, Sheng-Luen ; Shynk, John J.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of California, Santa Barbara, CA
Abstract :
In cellular wideband code-division multiple-access (WCDMA) systems, several transmitted data sequences can be separated because of the unique spreading codes which are designed to be orthogonal. However, cochannel interference and multipath propagation usually destroy this orthogonality at the receiver. We present a composite cyclodespreader that compensates for this distortion by exploiting the cyclostationary property of WCDMA signals, and uses a minimum mean-squareerror criterion to compute a composite despreading code. A semiblind beamformer that utilizes estimated physical channels as an extended training sequence is also employed in the receiver to improve the interference rejection capability in a high interference environment.
Keywords :
cellular radio; channel estimation; cochannel interference; code division multiple access; codes; least mean squares methods; WCDMA; cellular wideband code-division multiple-access systems; cochannel interference; composite cyclodespreader; composite despreading code; data sequences; interference rejection capability; minimum mean-square-error criterion; multipath propagation; physical channel estimation; semiblind beamformer; spreading codes; Base stations; Code standards; Distortion; Downlink; Frequency; Interchannel interference; Multiaccess communication; Optical signal processing; Receivers; Wideband;
Conference_Titel :
Information Sciences and Systems, 2009. CISS 2009. 43rd Annual Conference on
Conference_Location :
Baltimore, MD
Print_ISBN :
978-1-4244-2733-8
Electronic_ISBN :
978-1-4244-2734-5
DOI :
10.1109/CISS.2009.5054725
