Patent ID: 8130140

Claim:
A method of determining weights to be used onboard a satellite for a signal transmitted from a communication device and received at each of a plurality of antenna elements, comprising: selecting initial values for onboard beamforming weights; for each of a plurality of positions of a remote communication device in the field of view of the satellite: applying the onboard beamforming weights to M signals derived from a signal received from the remote communication device at the M plurality of antenna elements of the satellite and combining signals resulting from applying the onboard beamforming weights to the M signals to produce L downlink signals, where L is less than M; computing optimal ground-based beamforming weights for combining the L downlink signals; applying the optimal ground-based beamforming weights to the L downlink signals and combining signals resulting from applying the optimal ground-based beamforming weights to the L downlink signals to produce a beamformed output signal; computing a signal-to-noise ratio of the beamformed output signal; determining the minimal signal-to-noise ratio for said plurality of positions; and selecting values for said onboard beamforming weights to maximize the minimal signal-to-noise ratio of the beamformed output signal.