Northrop Grumman Systems Corporation

Trw Limited

Michael S Munoz

David A Wright

Dennis A Nivens

Scott Adam Stephens

Gregory S Caso

Reginald Jue

William F Courtney

Dominic P Carrozza

Terrence R Smigla

Ray M Nuber

Garrick Jon Harmon

Eric R Wiswell

David L Brundrett

Peter J Hadinger

Cyrus Dhalla

Hau H Ho

Raymond M Nuber

Steven L Branscombe

Fritz B Mezger

A digital automatic level control system employs delay elements, which enable information about a signal parameter from the past, present and future to be processed to provide an optimal gain that can be used to level rapidly varying signals, such as bursty signals. As digital time samples of a signal are passed through first and second buffers, first and second accumulators maintain running sums that are related to the sum of the samples presently in the first and second buffers, respectively. The sums in the first and second accumulators represent information about the signal parameter for the future and the past, respectively. By choosing the maximum of these two values, the system can anticipate the beginning of a signal burst, and still have enough delay to compensate the end of a signal burst. In one embodiment of the invention, multiple channel signals can be leveled, either individually or in groups.

Digital automatic level control system

A system and method for increasing the performance of a satellite communication system by using a multivariate analysis approach to optimize the pointing of the boresight of a satellite-mounted antenna. Optimizing the pointing of the boresight of the antenna minimizes sidelobe generation, and thus Co-Channel Interference (CCI) in geographic areas served by the system. By minimizing CCI, the overall system performance of the communication system is optimized. To optimize the pointing of the boresight of the antenna, the overall performance of the satellite communication system is determined, and the boresight of the antenna is iteratively repointed in the direction of increasing system performance until the optimized boresight pointing is determined. Alternatively, the frequency re-use plan of the satellite communication system may be analyzed to determine a high density cell region and the boresight may be pointed to the high density cell region.

Reducing co-channel interference in satellite communications systems by antenna re-pointing

A satellite communication system () includes apparatus for exchanging communication data between ground-based user sites (and) and a ground-based wideband network (). A communication satellite () exchanges user communication data with the user sites. Ground-based hub terminals (and) exchange the user communication data with the satellite () and also exchange the data with the network (). A communication manager () determines the communication requirements between the satellite and the network and identifies more than one hub terminal to exchange user communication data with the satellite in the event that one hub terminal is insufficient to meet the communication requirements.

Satellite communication apparatus with multiple hub stations providing increased bandwidth to meet service requirements

A method and apparatus for closed-loop power threshold leveling for a satellite communication system. An aspect of the present invention includes a plurality of user earth terminals (UET), a satellite and a network control center (NCC). The NCC polls the UETs to obtain power profile information. When polled, the UELTs form power profile responses and send the responses back to the NCC. The NCC forms a power profile database and statistically analyzes the power profile information to determine an uplink power threshold adjustment. The NCC transmits the uplink power threshold adjustment to the satellite, which adjusts an on-board uplink power level threshold in response to the uplink power threshold adjustment. In systems using mutltiple coding levels, the NCC determines uplink power offset values corresponding to the individual coding levels. The NCC delivers the uplink power offset values to the UETs which update their local power offset values.

Method and apparatus for controlling a transmission power threshold of a satellite communication system

A method and computer program to configure feeds on a satellite ( ) to provide for redundant coverage when a satellite ( ) fails. Further, this method and computer program can enable the switching of feeds from commands from a ground station ( ) to activate certain feeds and deactivate other feeds when demand for service changes. In addition, this method and computer program allow for repositioning of satellites so that when one satellite fails another satellite may take over its area of coverage by switching active feeds without the need for placing another satellite in orbit.

Method of configuring satellite constellation design using multiple discrete switchable spot beams

A method and system for controlling uplink power in a satellite communication system using error leveling is provided. The uplink power control system for a satellite communication system of a preferred embodiment of the present invention comprises a communication satellite ( ) and at least one UET ( ). The communication satellite ( ) includes an error detector ( ) and a comparator ( ). The UET ( ) includes a receiver ( ) for receiving an error indicator signal from the comparator ( ), and a power profile processor ( ) for controlling the transmit power level of the particular chanslot being used by the UET in response to the error indicator. A preferred method for controlling the transmit power level of a particular chanslot assigned to a UET in a satellite communication system in accordance with the present invention includes determining an error count for an uplink data signal received from the UET in the chanslot ( ), and comparing the error count to a predetermined error threshold ( ). The method further includes generating an error indicator signal for the chanslot in response to the comparison ( ), and controlling the transmit power level of the particular chanslot in response to the error indicator ( ).

Method and system for controlling uplink power in a satellite communication system using error leveling

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Redondo Beach, CA, United States of America

Michael S Munoz