The Directv Group, Inc.

Hughes Electronics Corporation

The Boeing Company

Weizheng W Wang

Donald C D Chang

Ying J Feria

Ernest C Chen

Ming U Chang

Tung-Sheng Lin

Kar W Yung

Frank A Hagen

William C Lindsey

Joseph Santoru

Guangcai Zhou

Alan Cha

Wah L Lim

Harold A Rosen

Anchung Chang

John I Novak, Iii

Stephen F Sichi

Bruce A Tomei

Alan c/o The Directv Group Inc Cha

Donald CD Chang

A system for protecting a power unit on a spacecraft may include a ground station. The ground station may include a power unit loading estimation and monitoring module for estimating a power loading level on a power unit of the spacecraft power unit. The ground station may also include a ground station power limiter to regulate a power of a signal for transmission from the ground station to the spacecraft to prevent overloading the spacecraft power unit. The power of the signal for transmission to the spacecraft may be regulated based at least in part on an estimated power loading level on the power unit of the spacecraft.

Power management scheme for protecting components on board a spacecraft

A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a training sequence including an idealized input signal, wherein the training sequence is comprised of adjacent symbols in the input data, and generating equalizer parameters from the training sequence. The apparatus comprises a demodulator (for demodulating an input signal to produce a data output), a modulator communicatively coupled to the demodulator (for remodulating the data output to produce a training sequence including an idealized input signal wherein the training sequence is comprised of adjacent symbols in the input data), and a parameter generation module communicatively coupled to the modulator (for generating equalizer parameters from the training sequence).

Equalizers for layered modulated and other signals

Devices and methods are disclosed for reducing power control cushion of a user terminal configured to communicate with a satellite and a gateway station. The present invention provides a power control algorithm implemented in a user terminal that is designed to operate in a satellite communication system. The power control algorithm can recursively calculate a returnlink power to reduce a power control cushion so that an extra link margin is available to the satellite communication system. The present invention also provides a source coding technique that provides an accurate feedback signal for the user terminal. The average metric of input signal frames is coded in a sequence of bits that are carried by contiguous output signal frames.

Innovative combinational closed-loop and open-loop satellite user terminal power control system

A method and apparatus for transmitting and receiving a coded signal having an upper layer signal and a lower layer signal is disclosed. The method comprises the steps of combining the upper layer signal and the lower layer signal, encoding the combined upper layer signal and lower layer signal, delaying the upper layer signal, modulating the delayed upper layer signal, modulating the lower layer signal, transmitting the delayed upper layer signal and transmitting the lower layer signal. The apparatus comprises an encoder, for encoding a combined upper layer signal and lower layer signal, a delay, communicatively coupled to the encoder, for delaying the upper layer signal, a first modulator, for modulating the delayed upper layer signal, a second modulator, for modulating the lower layer signal, a transmitter, communicatively coupled to the first modulator, for transmitting the delayed upper layer signal, and a second transmitter, communicatively coupled to the second modulator.

Lower complexity layered modulation signal processor

A method and apparatus for equalizing digital data signals is disclosed. The method comprises the steps of demodulating and decoding an input signal having input data to produce a data output, remodulating the data output to produce a pseudo-training sequence including an idealized input signal, and generating equalizer parameters from the pseudo-training sequence. The apparatus comprises a demodulator for demodulating an input signal to produce a data output, a modulator, communicatively coupled to the demodulator, for remodulating the data output to produce a pseudo-training sequence including an idealized input signal, and a parameter generation module, communicatively coupled to the modulator for generating equalizer parameters from the pseudo-training sequence.

Unblind equalizer architecture for digital communication systems

A method and apparatus for optimizing a system for transmitting a layered modulated signal is disclosed. The method comprises the steps of defining the system in terms of a set of system parameters, including an optimal power separation S between a power of a first modulation layer and a power of a second modulation layer and a required system carrier-to-noise ratio (CNR), determining an optimal power separation S to minimize the error rate of a lower layer modulated signal BER, and selecting the remaining system parameters in the set of system parameters using the determined optimal power separation S.

Optimization technique for layered modulation

A communications system () and method of operating the communications system includes a first stratospheric platform generating a second beam having a frequency the same as a satellite beam to the same service area. User terminals are configured to receive the first beam or the second beam.

Communication system as a secondary platform with frequency reuse

A method for communicating and a communications system apparatus are disclosed. The apparatus comprises a communications platform and a gateway communicatively coupleable with a terrestrially-based network. The communications platform is disposed in a stratospheric location and transponds information between at least one of a plurality of user terminals and the gateway in essentially a bent pipe fashion. The method comprises the steps of receiving a first signal from the user terminal having an antenna in a stratospherically-based communication platform that maintains an apparent position relative to the user terminal within a beamwidth of a user terminal antenna and transponding the first signal from the stratospherically based communications platform to a gateway ground station.

GEO stationary communications system with minimal delay

A system and method for tracking a user. The system is adapted for use in a wireless communication system and creates a plurality of beams within a coverage area. A first beam is directed at a user in a first microcell and a number of additional beams illuminate microcells immediately adjacent the first microcell. The system is equipped with a mechanism for detecting movement of the user from the first microcell to one of the immediately adjacent microcells. On the detection of movement of the user, the system redirects the first beam from the first microcell to a second microcell, the second microcell being one of the adjacent microcells. In the illustrative embodiment, the system is implemented in a stratospheric platform based communication system including a hub adapted to communicate with a stratospheric platform. A transceiver and a phased array antenna are disposed on the platform to communicate with the hub and with the user. A second antenna is provided on the platform to communicate with the hub. Beamforming and direction are implemented on the hub and communicated to the platform. The user's position is detected with a global positioning system receiver, by measuring the strength of a signal received from the user, or by other suitable means. On detection of user movement from the first microcell, the beamforming system redirects the beam to follow the user into a second microcell. Additional beams around the user's microcell are illuminated to facilitate detection of the users movement.

Micro cell architecture for mobile user tracking communication system

A method for integrating coverage areas of multiple transponder platforms includes the step of arranging a plurality of coverage areas in a cluster wherein each of the plurality of coverage areas is assigned a color that differs from that of every other coverage area in a same cluster and wherein each of the plurality of coverage areas overlaps at least one other coverage area in the same cluster for maximizing utilization of multiple system resources.

Growing community of inventors

Rancho Palos Verdes, CA, United States of America

Weizheng W Wang