METHOD AND APPARATUS FOR MULTIPLEXING COMMUNICATIONS SIGNALS THROUGH BLIND ADAPTIVE SPATIAL FILTERING

A method and apparatus for spatial multiplexing of spectrally overlapping communications signals which does not require use of a training signal, computationally intensive direction-finding methods, or antenna calibration is presented. An adaptive antenna array at a base station is used in conjunction with signal processing through self coherence restoral to separate the temporally and spectrally overlapping signals of users that arrive from different specific locations within the locale and to mitigate multipath fading and shadowing at the base station and, by reciprocity, to transmit directively to minimize interfering signals arriving at the mobile (or portable or stationary) units and to mitigate multipath fading and shadowing at the mobile units. The radiation pattern of transmitted signal is matched to the adapted reception pattern of the signal received at the base station. PAC BACKGROUND OF THE INVENTION The Government has rights in this invention pursuant to Grant No. MIP-88-12902 awarded by the National Science Foundation.