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Summary: 3846 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 56, NO. 6, NOVEMBER 2007
Reduced-Rank Adaptive Filtering Using Localized
Processing for CDMA Systems
Rebecca Y. M. Wong and Raviraj Adve, Senior Member, IEEE
Abstract--An integrated beamforming (spatial processing) and
multiuser-detection (temporal processing) scheme is an effective
approach to increase system capacity but is also impractical due
to the high associated computational costs. To overcome this
problem, researchers have developed reduced-rank approaches.
Adding to this class of algorithms, this paper introduces a joint-
domain adaptive algorithm, which processes spatial and tem-
poral data within a localized region after transformation to a
"beamspace." This new joint-domain-localized (JDL) adaptive al-
gorithm is developed for single-cell uplink code-division multiple-
access (CDMA) systems with a receive-antenna array. Given a
rank constraint on the JDL transformation, this paper develops
the optimal choice of transformation matrix and justifies a simpler
suboptimal choice. The JDL algorithm is shown to have relatively
low computation load. We also introduce the JDL-Z algorithm that
combines JDL processing with zero forcing for multicell uplink
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