Efficient multiuser receivers for CDMA systems

We focus on the design of multiuser receiver structures for code division multiple access (CDMA) communication systems, in the presence of multipath effects and multiple sensors at the base station receiver. We present a flexible and extensible framework that allows the use of an estimated effective spreading code from the channel estimation phase, in the multiuser detection process. The effective spreading code captures all the channel parameters such as path delays, attenuation factors, and directions of arrival. Hence estimation of this one composite vector removes the necessity of estimating each individual parameter, thus reducing computational complexity. The results also show that this approach leads to better performance for multiuser detection, especially when the channel consists of a number of low energy paths in addition to a few discrete strong paths.