Adaptive spatial filtering for co-channel interference rejection in narrowband digital cellular systems

The problem of adapting a spatial filter to reject co-channel interference experienced in narrowband digital cellular systems, and IS-54 in particular, is addressed. A two-part approach using blind adaptive spatial filtering and decision-directed adaptive spatial filtering is proposed to circumvent the difficulties associated with the use of training signals or schemes based on direction finding. A spatial filter, blindly adapted using the Phase SCORE algorithm, obtains an initial estimate of the symbol stream. Decision-directed adaptation then further refines this spatial filter to obtain a high-quality estimate of the desired symbol stream. Computer simulation results illustrate the successful operation of the new scheme