Arrays of randomly spaced sensors

This paper considers a class of blind beamforming problems in which the amount of prior information is very limited. The array sensors are placed in unknown locations within a geographical region, and have unknown frequency/spatial response. The sensors communicate synchronously with a main processor unit. The array is illuminated by a source, which may be narrow- or broadband, in near or far field. Additional disturbances may be present, in the form of interferers, possibly correlated or coherent with the main signal, and additive noise. The goal is required to steer beam toward the desired signal. Four schemes are presented, each based on the type of prior available information.