This research consists of four major objectives: (1) The development of powerful, rapid, hybrid acquisition schemes designed to operate in channels containing multiple-access interference, fading, and multipath. These schemes will be designed to acquire signals rapidly and reliably even under severe channel conditions. (2) The creation of a new class of sequential multihypothesis tests based on pipelining, a paradigm akin to a parallel server queueing system. (3) The development of acquisition schemes that exploit the presence of multipath. (4) A determination of the acquisition-based capacity of direct sequence CDMA communications and the acquisition-limited throughput of packet-data CDMA in third generation cellular communications systems. Significant advances in sequential decision theory are sought in the study, and the results will be applicable to systems ranging from multiple-resolution radar systems to PCS systems.