Adaptive multi-sensor receivers for frequency selective channels in DS-CDMA communications systems

The performance of two adaptive multi-sensor least squares (LS) receivers for a frequency-selective fading channel are evaluated. These two receivers are preceded by a RAKE which combines the resolvable paths of each channel of the desired user before further interference suppression. In the first, a LS space-time filter is used to accomplish despreading and interference rejection simultaneously. The second is a spatial-temporal version of the partial despreading LS (prds-LS) as proposed in Singh and Milstein (1997). For the partial despreading structure, the number of coefficients are reduced compared to the LS structure. If the desired user's channel coefficients are known, the multi-sensor prds-LS is very attractive for DS-CDMA systems with large processing gain in terms of both complexity and tracking performance.