Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A high throughput satellite communication system and method of satellite communication that provide loopback capability and increased throughput is disclosed. The satellite communication system and method of satellite communication utilize pre-distortion based on remotely estimated characteristics of a satellite transponder's power amplifier (PA). The pre-distortion is applied to the hub modulator's constellation.

Abstract: A return channel system for ultra-small aperture terminals has a spreader that receives an input signal and outputs a spread spectrum signal having multiple replicated signals with a lower power than the input signal. A de-spreader includes a de-multiplexer that receives the spread spectrum signal via satellite. The de-multiplexer separates the spread spectrum signal into a first channel having a first signal and a second channel having a second signal. The de-spreader also has an offset compensation circuit having a phase estimator configured to estimate a phase offset between a phase of the first signal and a phase of the second signal. And a phase adjustor that receives the second signal and adjusts the phase of the second signal to align with the phase of the first signal to provide a phase-adjusted second signal. A summer combines the first signal with the phase-adjusted second signal to provide a composite signal.

Abstract: A return channel system for ultra-small aperture terminals has a spreader that receives an input signal and outputs a spread spectrum signal having multiple replicated signals with a lower power than the input signal. A de-spreader includes a de-multiplexer that receives the spread spectrum signal via satellite. The de-multiplexer separates the spread spectrum signal into a first channel having a first signal and a second channel having a second signal. The de-spreader also has an offset compensation circuit having a phase estimator configured to estimate a phase offset between a phase of the first signal and a phase of the second signal. And a phase adjustor that receives the second signal and adjusts the phase of the second signal to align with the phase of the first signal to provide a phase-adjusted second signal. A summer combines the first signal with the phase-adjusted second signal to provide a composite signal.

Abstract: At least two antennas are used for make-before-break communications over non-geostationary satellites. An SHDC device provides physical layer seamless hand-off and obtain diversity signal-to-noise ratio (SNR) gain. When additional antennas are available for standby or other reasons, it may be beneficial for a number of satellite antennas to collectively utilize additional SHDC devices to achieve higher diversity SNR gains under normal operational considerations. The asymptotic SNR gains are those obtained when receiver antenna noise dominates transponder and sky noises. According to exemplary embodiment of the present invention, N satellite antennas may collectively utilize N?1 SHDC devices. For example, 3 satellite antennas may collectively utilize 2 SHDC devices.

Abstract: A high throughput satellite communication system and method of satellite communication that provide loopback capability and increased throughput is disclosed. The satellite communication system and method of satellite communication utilize pre-distortion based on remotely estimated characteristics of a satellite transponder's power amplifier (PA). The pre-distortion is applied to the hub modulator's constellation.

Abstract: At least two antennas are used for make-before-break communications over non-geostationary satellites. An SHDC device provides physical layer seamless hand-off and obtain diversity signal-to-noise ratio (SNR) gain. When additional antennas are available for standby or other reasons, it may be beneficial for a number of satellite antennas to collectively utilize additional SHDC devices to achieve higher diversity SNR gains under normal operational considerations. The asymptotic SNR gains are those obtained when receiver antenna noise dominates transponder and sky noises. According to exemplary embodiment of the present invention, N satellite antennas may collectively utilize N-1 SHDC devices. For example, 3 satellite antennas may collectively utilize 2 SHDC devices.

Abstract: A system and method for performing automatic uplink power control (AUPC), using interference cancellation, to compensate for signal attenuation in a satellite communication system in which uplink path attenuation, forward channel attenuation, or both are estimated at a hub station without requiring signal quality reports from a remote station, and without requiring a satellite beacon. Estimates of uplink path attenuation or forward channel attenuation are used by the hub station to control the output power of a transmitted signal, thereby compensating for the estimated attenuation.

Abstract: A system and method of reducing VSAT apertures via satellite MIMO is disclosed.

Abstract: A technique for interference cancellation in a satellite communication system involves an autocorrelation on the hub signal to detect a periodicity in the hub signal, determining a search range for a delay in the hub echo signal in accordance with the periodicity, locating the delay in the hub echo signal, and performing the interference cancellation in accordance with the delay. In the case of periodicity, a delay is acquired (either true or false) that provides cancellation (provided that the period does not change). When the period changes, cancellation is discovered to be poor, and another delay (that may be true or false) is acquired that provides good cancellation and so on.

Abstract: The reduction of echo noise in satellite communications includes receiving an aggregate signal from multiple remote stations, where the aggregate signal includes a transmit signal, whose bandwidth is in the range of 0.1 MHz to 66 MHz, is previously sent from a hub to the multiple receiving stations, computing a scaled, delayed and distorted replica of the transmit signal and using the replica to compensate for satellite transponder nonlinearities and reduce echo noise interference from a received aggregate signal received by the hub from the multiple remote stations.

Abstract: A system and method for performing automatic uplink power control (AUPC), using interference cancellation, to compensate for signal attenuation in a satellite communication system in which uplink path attenuation, forward channel attenuation, or both are estimated at a hub station without requiring signal quality reports from a remote station, and without requiring a satellite beacon. Estimates of uplink path attenuation or forward channel attenuation are used by the hub station to control the output power of a transmitted signal, thereby compensating for the estimated attenuation.

Abstract: A technique for interference cancellation in a satellite communication system involves an autocorrelation on the hub signal to detect a periodicity in the hub signal, determining a search range for a delay in the hub echo signal in accordance with the periodicity, locating the delay in the hub echo signal, and performing the interference cancellation in accordance with the delay. In the case of periodicity, a delay is acquired (either true or false) that provides cancellation (provided that the period does not change). When the period changes, cancellation is discovered to be poor, and another delay (that may be true or false) is acquired that provides good cancellation and so on.

Abstract: The reduction of echo noise in satellite communications includes receiving an aggregate signal from multiple remote stations, where the aggregate signal includes a transmit signal, whose bandwidth is in the range of 0.1 MHz to 66 MHz, is previously sent from a hub to the multiple receiving stations, computing a scaled, delayed and distorted replica of the transmit signal and using the replica to compensate for satellite transponder nonlinearities and reduce echo noise interference from a received aggregate signal received by the hub from the multiple remote stations.

Abstract: The reduction of echo noise in satellite communications includes receiving an aggregate signal from multiple remote stations, where the aggregate signal includes a transmit signal, whose bandwidth is in the range of 0.1 MHz to 66 MHz, is previously sent from a hub to the multiple receiving stations, computing a scaled, delayed and distorted replica of the transmit signal and using the replica to compensate for satellite transponder nonlinearities and reduce echo noise interference from a received aggregate signal received by the hub from the multiple remote stations.