Channel-Individual Adaptive Beamforming for Mobile Satellite Communications

A digital frequency-division multiplex demultiplexer for single channel per carrier (SCPC) signals was developed for use in a digital channel-individual beamforming network for an adaptive satellite array antenna for mobile satellite communications. The available ASIC (35000 gate functions in CMOS technology, clock rate up to 30 MHz with low power consumption) permits the separation of FDM signals comprising up to 16 channels. Starting from a suitable model for the demultiplexer beamforming system, this paper describes the analysis, design, simulation and implementation of the hierarchically structured demultiplexer. Aspects of digital beamforming are only discussed as far as necessary for understanding. >