Rake finger allocation in the DS-CDMA uplink
Ali S. Khayrallah, Gregory E. Bottomley · 2006
In a cellular direct-sequence code-division multiple- access (DS-CDMA) base station, each user signal is recovered using a dedicated set of Rake receiver fingers that collect energy together. In this paper, we explore allocating users different numbers of fingers from a pool of fingers. An approach for finger allocation is developed based on channel probing, in which the instantaneous fading of each path is monitored. Performance is studied for a single-cell Wideband CDMA (WCDMA) system with power control, showing how finger allocation impacts per- formance in terms of coverage (range), capacity, and complexity. Results show that pooling is most beneficial when users have different delay spreads or different data rates. Also, channel probing is shown to have a significant impact on performance. I. INTRODUCTION