Spatial path separation and path diversity in 3G multimedia mobile communications using Intelligent Pre-Rake Processing in MISO channels

This paper studies the use of intelligent (INT) pre-rake combining in direct sequence spread spectrum code-division multiple-access (DS-SS/CDMA) systems. The study considers multipath Rayleigh fading channels in the downlink in single input single output (SISO) and multiple input single output (MISO) environments. The used modulation technique is binary PSK (BPSK) with time division duplexing (TDD) and maximal ratio combining (MRC). The INT pre-rake processing selects the paths with the highest gains for transmission. Two scenarios are considered. The first approach explores the effect of using multiple antennas at the transmitter (MISO) on the system performance for different number of users and processing gains. The second approach is to study the usage of INT pre-rake and compare it to the conventional pre-rake and the generalized selection (GS) pre-rake in MISO channels.