Joint domain localized adaptive processing for CDMA systems

An effective approach to increase system capacity would be combining space division multiple access (SDMA) with other multiple access approaches such as code division multiple access (CDMA). However, implementing such a system requires interference cancellation to separate users´ signals spatially and/or temporally. In this regard, an integrated beamforming (spatial processing) and multiuser detection (temporal processing) scheme outperforms all linear processing schemes, but is also impractical due to the high computational costs. Other researchers have proposed some more practical reduced-rank or iterative schemes. This paper introduces a joint domain adaptive algorithm which processes spatial and temporal data within a localized region in beamspace. This new algorithm is developed for uplink CDMA systems with multiple receive antennas. The simulations show that this approach is more effective than the reduced rank and iterative schemes in suppressing interference at significantly lower computational cost.