Viasat, Inc.

Visat, Inc.

Effect Photonics B.v.

Fan Mo

Sameep Dave

Mark Vanderaar

Kevin Kimmich

William H Thesling

Yuri Zelensky

Murat Arabaci

Matthew D Nimon

Russell Fuerst

Richard Harel

Eric A Fowlie

Daniel Kang

Timothy K Gao

Chase B Nemeth-Neumann

William H Miller

Lawrence W Esker

Richard T Gedney

Andy Lincoln

Methods, systems, and devices are described for communicating data from multiple data terminals to an aggregator terminal over a communication link having changing link conditions. In some embodiments, source data is received at multiple data terminals, each in communication with an aggregator terminal over a communication link. For example, during a live newscast, one mobile camera may receive live video of an event from a first position while another mobile camera receives live video of the event from a second position. For various reasons (e.g., as the cameras move) each communication link may experience independently changing link conditions. Each data terminal encodes the source data (or store source data for later encoding) as a function of its respective link conditions and transmits encoded source data over its respective communication link to the aggregator terminal.

Opportunistic progressive encoding

A system and method of creating frames comprised of blocks, where each block comprises data symbols corresponding to a higher order quadrature modulation format and support symbols corresponding to a lower order modulation format. One or more of the blocks can further comprise markers comprising distinct symbol patterns. The markers can mark the start of each frame and/or another location in the frame. The support symbols can be in a common location in each block.

Systems and methods for creating in a transmitter a stream of symbol frames configured for efficient processing in a receiver

Methods, systems, and devices are described for communicating data from multiple data terminals to an aggregator terminal over a communication link having changing link conditions. In some embodiments, source data is received at multiple data terminals, each in communication with an aggregator terminal over a communication link. For example, during a live newscast, one mobile camera may receive live video of an event from a first position while another mobile camera receives live video of the event from a second position. For various reasons (e.g., as the cameras move) each communication link may experience independently changing link conditions. Each data terminal encodes the source data (or store source data for later encoding) as a function of its respective link conditions, and transmits encoded source data over its respective communication link to the aggregator terminal.

One example includes a frame synchronization module. The module includes a search correlator configured to find a first unique word (UW) pattern in a first set of digital sample blocks of a first data frame and a second UW pattern in a second digital sample blocks of a second data frame. The module also includes a buffer configured to store the first and second data frames and to concurrently release the buffered first and second data frames for downstream processing in response to time-aligning the first and second UW patterns of the respective first and second sets of digital sample blocks being aligned to a clock index.

Synchronizing and aligning sample frames received on multi-component signals at a communications receiver

A system and method of estimating metric values from digital samples of received communications signal carrying symbols modulated in a selected first modulation format and symbols modulated in a second modulation format. The selected first modulation format can be selected from among multiple supported first modulation formats. The system can receive the digital samples in sample blocks a plurality of which constitute a data frame. Each sample block can comprise a first region that contains first samples corresponding to the selected first modulation format or overhead samples regardless of the selected first modulator format or an index of the sample block in the frame; a second region that contains second samples corresponding to a second modulation format regardless of the selected first modulator format or an index of the sample block in the frame; and a third region in which whether the samples are first samples or second samples depends on the selected first modulation format or the index of the sample block in the frame. The system estimates first metrics according to the selected first modulation format for each of the first samples and second metrics according to the second modulation format for each of the second samples. The system also estimates both first metrics and second metrics for each of the third samples and then selects valid ones of the first metrics and second metrics for the third samples in accordance with the selected first modulation format or the index of the sample block in the frame.

Generating metrics from samples of a received signal in a communications receiver supporting multiple operating modes

One example includes an equalizer system. The system includes a filter system configured to receive digital sample blocks associated with an input signal and to provide equalized digital sample blocks associated with the respective digital sample blocks based on adaptive tap weights. Each of the digital sample blocks includes samples and each of the equalized digital sample blocks includes equalized samples. The system also includes a sample set selector to select a subset of equalized samples from each of the equalized digital sample blocks at the output of the filter and an error estimator configured to implement an error estimation algorithm on the subset of the equalized samples to determine a residual error associated with the equalized samples. The system further includes a tap weight generator configured to generate the adaptive tap weights in response to the residual error and to provide the adaptive tap weights to the filter.

Adaptive equalizer system

One example includes a digital signal conditioner (DSC) system. A sample selector bank receives a digital sample block of an input signal that is provided at a supported input oversampling factor and selects a subset of samples from the digital sample block based on a selection signal. A tap weights selector bank generates a set of tap weights based on the selection signal. A filter bank receives the subset of the samples from each of the sample selectors and a respective set of tap weights. Each filter provides a weighted sample associated with the respective subset of samples and the respective set of tap weights. A reformattor receives the weighted sample from each of the filters and provides a filtered sample block including the weighted sample from a subset of the filters at an output oversampling factor for each supported input oversampling factor based on a selected supported resampling ratio.

Digital signal conditioner system

A frame synchronization system and method is disclosed. The system can comprise controller, a search correlator, and a buffer. The controller can be configured to operate on a first stream of first digital sample blocks associated with a first signal and a second stream of second digital sample blocks associated with a second signal. The search correlator can be configured to determine an index of a first unique word (UW) pattern within first searchable digital sample blocks corresponding to the first digital sample blocks and an index of a second UW pattern within second searchable digital sample blocks corresponding to the second digital sample blocks. The buffer can be configured to store the first digital sample blocks and the second digital sample blocks and to release the buffered first and the second digital sample blocks for flow downstream when the stream of first digital sample blocks and the stream of second digital sample blocks are aligned.

Methods, systems, and devices are described for modulating and demodulating data on optical signals. During modulation, at least one stream of symbol mapped bits is filtered with at least one pulse shaping filter to reduce a bandwidth of the stream of bits and to pre-compensate for at least one identified non-ideal transmission condition. The filtered bits are modulated onto a waveform in the digital domain, and the modulated filtered bits are transmitted to digital-to-analog converter. The output of the digital-to-analog converter is converted to an optical signal. During demodulation, a received optical signal is sampled at a first sampling rate at an ADC, downsampled to a lower sampling rate for filtering, filtered with at least one discrete pulse-shaping filter, upsampled for equalization and demodulation, and then equalized and demodulated.

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Hinckley, OH, United States of America

Fan Mo