Hughes Network Systems, LLC

Liping Chen

Lin-Nan Lee

Mustafa Eroz

Rohit Iyer Seshadri

Stanley Edward Kay

Stan Kay

Bassel F Beidas

Victor Liau

Yanlai Liu

Uday Ramachandra Rao Bhaskar

Bala Subramaniam

Satyajit Roy

Neal David Becker

Anthony Robert Noerpel

Sri Bhat

Lin-nan Lee

Donglei Fan

Srilekha Bhat

Anthony Noerpel

Methods, systems, and apparatus for transmodulation in multi-beam satellite communication systems. In some implementations, a gateway receives bitstreams for transmission on different forward links from a satellite to terminals. The gateway is configured to modulate data for transmission on a feeder link for transmissions from the gateway to a satellite, including using a same symbol constellation to modulate data to provide different numbers of bits per symbol. The gateway can be configured to select symbols for transmission from among different subsets of the symbols in the symbol constellation to achieve different numbers of bits per symbol. The gateway can also be configured to select symbols for transmission from among one of the subsets determined based at least in part on a measure of signal strength for the feeder link.

Adaptive constellation for transmodulation in satellite communication systems

Various arrangements for performing transmodulation of a forward feeder link are presented. A first data stream and a second data stream can be modulated into a higher-order modulation forward feeder link having a higher-order digital modulation scheme. A satellite can receive the higher-order modulation forward feeder link. The satellite can demodulate the higher-order modulator forward feeder link into a bit stream. This bit stream may then be remodulated and retransmitted as multiple forward user links.

Transmodulation for a multi-beam satellite communication system

Systems and methods for processing bit-interleaved coded modulation (BICM) signals from a BICM transmitter to generate information bit estimates of information in the BICM signals, including a decoder to generate the information bit estimates of the information in the received BICM signals and a symbol a posteriori probability (APP) generator to generate first symbol a posteriori probabilities (APPs) by processing the BICM signals based on Euclidean distances derived from the BICM signals, and further based on symbol probability log-likelihood ratios (SPLLRs) provided to the symbol APP generator by an extrinsic-information-based symbol probability log-likelihood ratio (SPLLR) generator. The SPLLR generator generates the SPLLRs directly from extrinsic information based on updated symbol APPs output from the decoder, without converting the extrinsic information into log-likelihoods (LLs), and the decoder generates the information bit estimates based on the first symbol APPs output from the symbol APP generator.

Simplified system and method for bit-interleaved coded modulation with iterative decoding (BICM-ID)

The disclosure relates to bit-interleaved coded modulation with iterative decoding. In some implementations, a receiver comprises: a first memory including multiple first sub-memories; a decoder configured to perform first operations comprising: calculating, first extrinsic information of multiple code bits associated with multiple received symbols; and a demapper configured to perform second operations comprising: calculating soft decision information of the code bits; calculating, based on the soft decision information and the first extrinsic information, second extrinsic information of the code bits; and writing the second extrinsic information of the code bits into the first memory such that, for each received symbol, each sub-memory of the first sub-memories respectively stores the second extrinsic information associated with a respective one of the code bits corresponding to the received symbol.

Bit interleaved coded modulation-iterative decoder for high-speed receiver

A system and method for estimating a geolocation The method includes subdividing the camping cell into grid points where each grid point of the grid points has an associated relative offset from a camping beam center; illuminating the camping cell with a camping beam and each of the adjacent cells with adjacent beams; receiving a camping beam signal strength and adjacent beams signal strengths for each grid point of the grid points; profiling, at each grid point of the grid points, ratios of the camping beam signal strength to each one of the adjacent beams signal strengths; mapping the ratios and the associated relative offset of each grid point of the grid points; and estimating a relative geolocation of a User Terminal (UT) from the camping beam center based on a UT camping beam signal strength and UT adjacent beams signal strengths.

Estimating geolocation of a user terminal

A geolocation is estimated by tessellating a coverage area into a camping cell and adjacent cells; subdividing the camping cell into grid points where each grid point of the grid points has an associated relative offset from a camping beam center; illuminating, with a platform, the camping cell with a camping beam and each of the adjacent cells with adjacent beams; receiving a camping beam signal strength and adjacent beams signal strengths for each grid point of the grid points; profiling, at each grid point, ratios of the camping beam signal strength to each one of the adjacent beams signal strengths; mapping the ratios and the associated relative offset of each grid point; and estimating a relative geolocation of a User Terminal (UT) from the camping beam center based on a UT camping beam signal strength and UT adjacent beams signal strengths.

A user terminal (UT) to transmit small amounts of data, the UT including: a packet including the data, where the packet is less than 128 bytes; a frequency synchronizer to synchronize a transmission frequency of an ASCMA return link connecting the UT with a satellite gateway; and an ASCMA transmitter to transmit, without acquiring timing synchronization with the satellite gateway from the UT, the packet modulated over the synchronized transmission frequency as an ASCMA waveform including a preamble to indicate a start of a transmission. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

Narrow band internet of things communications over a satellite communication system

A transmitter, including a signal processor programmed to generate, based on input serial data, for each of an integer number of subcarriers mutually orthogonal to each other, a respective first parallel data stream. The signal processor is further programmed to modulate each of the integer number of subcarriers respectively with the respective parallel stream to generate the integer number of data-modulated subcarriers. The signal processor is further programmed to modulate a single carrier occupying a same bandwidth as the integer number of subcarriers with a unique word and one or more pilot symbols to generate a second signal. The signal processor combines the first signal and second signal to generate a third signal. The signal processor generates an output signal by applying a transmit filter to the third signal.

Mitigation of partial band jamming for satellite communications

Systems and methods are disclosed, and one includes receiving a configuration specification data, including a cell floorplan data identifying a plurality of rectangular cells, and indicating a cell width and a cell length of each, in combination with determining, based at least in part on the configuration specification data, a spot beam pattern that provides a plurality of rectangular cell coverage regions, having the cell length and width.

System and method for pointing error resistant reuse

Interference cancellation in a receiver can be used to improve bandwidth efficiency. The transmission of bursts from different terminals scheduled at separate time intervals can overlap partially such that time used for information transmission is optimized. For example, a receiver includes a signal processor including instructions executable to select first data including a first burst and a successive second burst from a transmission. The signal processor demodulates and decodes information from the first burst. The signal processor further generates a remodulated first burst based on recoded and remodulated information and generates second data by subtracting the remodulated first burst from the first data. The signal processor synchronizes with a stored symbol pattern in the second burst; and demodulates and decodes the information from the second burst. With such arrangement, the performance of each link is not affected by the partially overlapping burst.

Time-division multiple access with overlapped preamble

Systems and method are disclosed and among these is a method for mitigation of interference local to remote terminals, and it can include detecting reception of a packet having one of the remote terminals as a destination terminal and, in response, selecting a sub-carrier among the sub-carriers that are not identified as receiving local interference at the destination terminal, and loading, into a queue for the selected sub-carrier, a coded data from which a content of the packet can be derived, and transmitting the queued coded data on the selected sub-carrier. Among disclosed features is a receiving of an interference report that carries an information indicative of a new local interference and, in response, updating the data identifying sub-carriers having local interference at the destination terminal.

System and method of adaptive interference avoidance in multi-beam satellite communications network

A receiver, transmitter and system are programmed to communicate based on a signal including a plurality of signal components associated respectively with a plurality of subcarriers over a communications channel. The receiver is programmed to determine, from the plurality of subcarriers, a subcarrier subject to interference and erase the signal component associated with the subcarrier subject to interference. The receiver is further programmed to reconstruct the signal based on the plurality of first signal components excluding the erased first signal component.

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Bethesda, MD, United States of America

Liping Chen