Angular Propagation Descriptions Relevant for Base Station Adaptive Antenna Operations

This paper presents basic short-term angular domain propagation descriptions relevant for beamoriented SDMA operations, i.e. for spatially based algorithms, contrary to temporally based. A distinction is made between angular variant and invariant situations, i.e. whether the antenna system radiation pattern remains unchanged or not when sweeping over the angular domain. For the angular invariant case, multibeam diversity relations are explained, as well as simple data enhancement techniques for measurement refinements. For the angular variant case using linear arrays, this paper suggests a representation in the invariant virtual Doppler domain. A key benefit of generating beams in the Doppler domain instead of directly in the angular domain is a substantial saving in numerical complexity.