Hughes Network Systems, LLC

Dtvg Licensing, Inc.

Hughes Electronics Corporation

The Directv Group, Inc.

Hughes Nerwork Systems, LLC

Neal David Becker

Stanley Edward Kay

Lin-Nan Lee

Mustafa Eroz

Yezdi F Antia

Uday R Bhaskar

Udaya Bhaskar

Feng-Wen Sun

Murali Regunathan

Yimin Jiang

Bassel F Beidas

Anthony Robert Noerpel

David Alan Roos

Rohit Iyer Seshadri

Liming Qin

Marwan Adas

Prachi Raikar

Lakshmi Iyer

Liping Chen

Dave Roos

Stan Kay

Lin-nan Lee

Richard Clewer

Russell Fang

J Mark Steber

Seokho Kim

Richard Sims

Stanley E Kay

A beamforming system for an antenna for satellite communications, where the antenna includes an array of radiating elements, the system including: a processor programmed to implement a set of averaging functions, the processor programmed to receive channel vectors representing responses from a center and other locations in each of a number of cells to be served, the averaging functions to produce an average channel vector for each cell based on an average of the channel vectors received from a corresponding cell; the processor further programmed to calculate a beam weight vector for each cell based on a corresponding average channel vector; and a beamformer to generate a beamforming matrix from the beam weight vectors and to use the beamforming matrix to drive the elements of the antenna to beamform a beam from the antenna.

Averaged beamforming for satellite communication

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)

An apparatus for synchronizing frequency to a symbol timing, the apparatus including: a master oscillator to generate a master clock signal; an interpolator to accumulate a frequency error estimate between a symbol timing frequency and the master clock signal; and a frequency controller to transfer a portion of the frequency error estimate to the master oscillator to obtain a lock between the symbol timing and the master clock signal of the master oscillator in a manner that zeros-out the frequency error estimate.

Method and apparatus for synchronizing frequency in remote terminals

Techniques described herein provide cancelation of cross-polarization interference during simultaneous receipt of radiofrequency signals (e.g., an X-signal and a Y-signal) in a same frequency channel in nominally orthogonal polarizations. Though nominally orthogonally polarized, each signal contributes some cross-polarization interference to the other. Embodiments receive and demodulate each signal by a corresponding demodulator to generate corresponding X-symbol and Y-symbol decision signals, referenced to a common clock domain. An X-channel adaptive canceler (X-CAC) generates an X-output signal by using one or more Y-symbol decision signals adaptively to cancel cross-polarization interference from the Y-signal, and a Y-CAC generates a Y-output signal by using one or more X-symbol decision signals adaptively to cancel cross-polarization interference from the X-signal (e.g., the X-CAC and the Y-CAC each using a first-order least mean squares control loop). The resulting X-output signal and Y-output signal can be further decoded and output by the receiver to downstream systems and/or components.

Simultaneous multi-polarization receiving with cross-polarization interference cancellation

A system and method for beamforming beams including: matching weights T to a distribution of resources for each of the beams based on a traffic variation for each of the beams; calculating, with a signal processor for each of the beams based on the weights T, a power scalar &#x3b2; and a weighted minimum mean squared error (WMMSE) matrix W; and transmitting/receiving the beams based on the power scalar &#x3b2; and the WMMSE matrix W, where the power scalar &#x3b2; satisfies a total power constraint of an antenna subsystem.

Beamformer accounting for non-homogeneity of offered traffic distribution among cells

A system and method for beamforming includes providing an antenna including feeds, a coverage area including service areas and data streams for each of the service areas; selecting a cluster of M feeds from the feeds; computing, with a GBBF processor (ground based beam former), M&#xd7;N weights; generating M feed excitations by distributing the N data streams per the M&#xd7;N weights; switching an array to transfer a respective one of the M feed excitations to a respective one of the M feeds; and beamforming, with the M feeds of the antenna, N beams. In the method, the N beams are each focused on a respective service area of each of the N data streams, the M&#xd7;N weights improve the transmitting into the respective service area of each of the N data streams, and at least one of the N beams includes a portion of a plurality of the M feed excitations.

Ground based beam forming with clustering

A system and method for scheduling a variable stayout distance when beam hopping, the method including providing an illumination area of a satellite and candidate beam centers disposed in the illumination area; measuring a respective scan angle from an antenna boresight to a respective beam center of the candidate beam centers; and determining a reuse factor k for each of the candidate beam centers, based on a proportion of the respective scan angle to a maximum scan angle. Each candidate beam center may be processed sequentially. Prior to adding each candidate beam center to a current beam center set, checking whether a candidate beam center meets the stayout distance criteria from all beam centers already in the beam center set.

Variable stayout distance for beamhopping satellite

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for compensating for frequency-dependent I-Q imbalance. In some implementations, a radio receiver includes an in-phase mixer configured to generate an in-phase (I) signal and a quadrature mixer configured to generate a quadrature (Q) signal. A first analog-to-digital (A/D) converter is configured to generate first digital samples from one of the I signal and the Q signal. A second analog-to-digital (A/D) converter is configured to generate second digital samples from the other of the I signal and the Q signal. A compensation system includes a feedback loop configured to compensate for frequency-dependent I-Q imbalance based on results, for each of multiple of the first digital samples, of cross-correlation of the first digital sample with each of multiple of the second digital samples.

Compensating for frequency-dependent I-Q phase imbalance

Systems and methods are described, and one method includes allocate a continuous duration within a TDMA scheme, for asynchronous NOMA transmissions, and extending from an allocation start time to an allocation termination time, formed of contiguous time slots of the TDMA scheme, and included providing to asynchronous NOMA user terminals an indication of the allocation start time and termination time, indicating allowance to perform asynchronous NOMA transmissions within a start time constraint that starts of the asynchronous NOMA transmissions do not precede the allocation start time, and terminations of the asynchronous NOMA transmissions do not succeed the allocation termination time.

Asynchronous non-orthogonal multiple access in a time/frequency division orthogonal multiple access network

A system and method for beamforming includes providing an antenna including feeds, a coverage area including service areas and data streams for each of the service areas; scheduling N data streams of the data streams, selecting a cluster of M feeds from the feeds; computing, with a GBBF processor (ground based beam former), M&#xd7;N weights; generating M feed excitations by distributing the N data streams per the M&#xd7;N weights; switching an array to transfer a respective one of the M feed excitations to a respective one of the M feeds; and beamforming, with the M feeds of the antenna, N beams. In the method, the N beams are each focused on a respective service area of each of the N data streams, the M&#xd7;N weights improve the transmitting into the respective service area of each of the N data streams, and at least one of the N beams includes a portion of a plurality of the M feed excitations.

Techniques for data transmission include a geostationary earth orbiting satellite that includes a first optical communication system configured to receive forward-direction user data via a forward optical link between the satellite and a stratospheric high-altitude communication device, and a first radio frequency (RF) communication system configured to transmit, via a plurality of RF spot beams, the forward-direction user data. The stratospheric high-altitude communication device includes a second RF communication system configured to receive the forward-direction user data via a plurality of concurrent forward RF feeder links, and a second optical communication system configured to transmit to the satellite, via the forward optical link, the forward-direction user data received via the plurality of forward RF feeder links. A substantial portion of forward feeder data throughput for all forward RF service link transmissions by the satellite is carried via the forward optical link and the plurality of forward RF feeder links.

Systems and methods for high-altitude radio/optical hybrid platform

A User Equipment and method for transmitting a random-access radio frequency (RF) signal by applying Asynchronous Coded Multiple Access (ACMA) in a communication system employing Orthogonal Frequency Division Multiplexing (OFDM) is described. The method including: encoding an information stream as OFDM symbols using a low rate Forward Error Correction (FEC) coding suitable for Successive Interference Cancellation (SIC) to form a payload; generating a burst, including symbols, by performing an inverse fast Fourier transform on a unique word (UW) multiplexed with the payload; and synchronizing a transmission of each of the symbols of the burst with consecutive symbol-start instants. The UW includes a plurality of Zadoff-Chu (ZC) like sequences disposed in a subset of consecutive symbol-start instants of the burst. A receiver detects burst arrival by searching for consecutive ZC-like sequences. Channel state estimation can be performed by using the UW with additional ZC-like sequences in the burst.

Growing community of inventors

Frederick, MD, United States of America

Neal David Becker