Adaptive antenna system for PACS

The PACS (Personal Access Communications System) has been standardized as a TDMA air interface for microcellular networks operating in the PCS band (1850-1990 MHz). In order to meet performance requirements, the standard suggests use of a simple dual diversity antenna system at the radio port (base station) and subscriber unit (mobile). Space-time signal processing can be used to enhance the PACS system, improving its coverage and capacity. We propose a hybrid transceiver architecture consisting of switched antennas and adaptive combining. The receiver at the radio port consists of a multiple sectored antenna array, a switch that selects the best two antennas, and an adaptive combiner for the two selected outputs. Transmission takes place on the best receive antenna. The receiver at the subscriber unit consists of two omnidirectional antennas and an adaptive combiner. Transmission takes place on the best antenna determined by word error feedback from the radio port. We present simulation results for the proposed architecture and describe the potential improvements in coverage and capacity