Hughes Network Systems, LLC

Hughes Nerwork Systems, LLC

Seokho Kim

Stanley Edward Kay

Neal David Becker

Yezdi F Antia

Murali Regunathan

Uday R Bhaskar

Santharam Gurumani

Sri Bhat

Brandon Lasher

Techniques are described for demodulating burst communications, such as for demodulating satellite beam-hopping communications in a demodulator of a very small aperture terminal (VSAT) satellite receiver. The demodulator includes a front-end and a sample/symbol domain processor. The front-end is configured to selectively operate in either of an adaptive mode or a freeze mode. During demodulation, the sample/symbol domain processor detects start of superframe (SOSF) and end of superframe (EOSF) locations to determine where each dwell time and non-dwell time begins and ends. During at least a portion or each dwell time, the front-end is set to operate in adaptive mode, in which the front-end uses feedback control from the sample/symbol domain processor to continuously adapt to timing and frequency of the received burst transmission. During at least the duration of each non-dwell time, the front-end is set to operate in freeze mode, in which adaptation of the front-end is frozen.

VSAT demodulator architecture for beam hopping satellite systems

A system and method for timing synchronization with a modified DVB-S2X waveform for a forward beam hopping satellite is described. The method includes: transmitting a channel including a plurality of beams per a Beam Hopping Time Plan (BHTP), wherein each beam includes a discontinuous signal including a superframe including timing markers and a Beam Hopping Forward Synchronization Pattern (BHFSP); receiving a synchronization information, without a loopback beam, for one of the plurality of beams; determining an adjustment period and an adjusted symbol rate for generation of terrestrial switching instants, based on the synchronization information, for a transmission of the plurality of beams such that at least a portion of a respective BHFSP of one of the beams aligns with one of satellite switching instants; and adjusting a timing and symbol rate of the transmission according to the adjustment period and the adjusted symbol rate, respectively.

Timing synchronization with a modified DVB-S2X waveform for a beam hopping satellite

A telecommunications system includes a satellite receiver programmed to estimate a Doppler frequency associated with a satellite signal. Estimating the Doppler frequency includes sampling the satellite signal, resampling the sampled satellite signal, and compensating for a frequency offset associated with the satellite signal. An example satellite receiver includes a sampling device programmed to sample the satellite signal, a resampling device programmed to sample the sampled satellite signal and output a resampled satellite signal, and an incremental phase modulator programmed to filter a frequency offset from the resampled satellite signal.

Satellite receiver doppler compensation using resampled satellite signals

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N. Potomac, MD, United States of America

Seokho Kim