Combined multipath and spatial resolution for multiuser detection: potentials and problems

Mobile telephony in CDMA channels encounters a variety of communication challenges including fading due to multipath (MP) and multiaccess interference (MAI) due to simultaneous transmissions from interfering users. Detectors which employ multiuser detection and temporal (RAKE-type) combining have been shown in Huang and Schwartz (1994) to provide near-far resistant solutions which effectively combat both of these impediments. In the first part of the present paper, we address the potential gains of using spatial combining in conjunction with multiuser detection and temporal combining. In the second part of the paper, we examine an adaptive multiuser detector which is well suited for MAI-limited MP channels