Ast & Science, LLC

Sriram Jayasimha

Huiwen Yao

Abel Avellan

Zhi Zhong Yu

Jyothendar Paladugula

Christos Kasparis

Peter King

David Wheeler

OFDM-BPSK symbol sequences are used for mutual-coupling based phase array calibration. Such substitution allows phase to be estimated more accurately using a given estimation duration without compromising other estimates (amplitude and group delay) accuracies.

Mutual coupling based calibration

A satellite communication system includes a phased antenna array having a field of view (FoV) and configured to communicate with a plurality of cells in the FoV via a plurality of beams. Each of the plurality of beams is associated with one of the plurality of cells. A phased antenna array is configured to apply adaptive taper selection, based on both the satellite position (in relation to a satellite service beam) and its surrounding interference scenario.

Adaptive taper selection for beamforming

A ground station processes downlink signals received from respective satellites. The ground station has a plurality of signal conditioning devices each receiving a respective one of the downlink signals and providing a conditioned downlink signal. A plurality of Doppler and/or Delay compensator devices each receive a respective conditioned downlink signal from a respective one of the plurality of signal conditioning devices. The compensator devices conduct Doppler and/or Delay compensation on the received conditioned downlink signal, and provide a compensated downlink signal output. A selector or diversity combiner receives the compensated downlink signal from each of the plurality of Doppler and/or Delay compensators. The selector or diversity combiner selects one of the received compensated downlink signals based on received signal strength of each received compensated downlink signal to provide a selected downlink signal, or diversity combines all of the received compensated downlink signals to provide a diversity combined signal. The selector or diversity combiner provides the selected downlink signal or the diversity combined signal to an eNodeB.

Selection, diversity combining or satellite MIMO to mitigate scintillation and/or near-terrestrial multipath to user devices

A base station for communication with a terminal station having a plurality of terminal station antennas. The base station has a plurality of directional antennas, each of the plurality of directional antennas in communication with satellites in view. The base station also has a processing device (e.g., eNodeB) to transmit each of the multiple base-station antenna signals via each of the plurality of directional antennas to satellites and/or the beams of the same satellite seen by the terminal station for retransmission to the plurality of terminal station antennas.

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Sriram Jayasimha