Motorola Corporation

Robert Anthony Peters

Thomas Peter Emmons, Jr

James William Startup

Shawn Wesley Hogberg

Jonathan Henry Gross

Peter Monsen

Norbert Kleiner

Duke Edward Hanson

Joel Lloyd Gross

James William Bishop, Jr

Craig L Fullerton

Daniel Francis DiFonzo

John Richard Erlick

Jim E Helm

Cynthia C Matthews

Michael Dane Ince

John G Lambrou

Susan L Harris

Allen H &lsquo;Skip&rsquo; Nelson

David L Krueger

A communications platform () assigns communication channels () to users based on a power level associated with the individual users. An available bandwidth for use by the communications platform () in segmented into a number of sub-bands using a bank of filters (). A number of independent communication channels () are then provided within each of the sub-bands using an appropriate multiple access scheme (e.g., code division multiple access). A power range is then specified for each of the sub-bands. When a communication connection is to be established, a power level associated with the connection is determined. One or more sub-bands are then identified that have power ranges encompassing the determined power level. A channel is then assigned to the communication connection from one of the identified sub-bands.

Power based channel assignment in a wireless communication system

The present invention utilizes a dual polarization reception system () that utilizes the energy available in orthogonal polarizations to effectively increase link margin, thereby allowing for adequate signal quality reception in difficult environments. A co-polarized and a cross-polarized signal are separately downconverted and demultiplexed. The signals from each demultiplexed output are then sampled and weighted. The weighted samples for each polarity are combined in soft decision combining/decoding circuitry (), and this circuitry determines the most likely state of a received symbol's transmitted value.

Mobile satellite communication system utilizing polarization diversity combining

A communication system provides multiple wireless services, each potentially having a different information bit rate. A transmitter (, FIG.) encodes (, FIG.) relatively low rate data (, FIG.) using code division multiple access (CDMA). The resulting spread data stream(s) (, FIG.) are multiplexed and modulated (, FIG.) along with relatively high information rate, non-encoded data streams (, FIG.) using a time division multiple access/frequency division multiple access (TDMA/FDMA) protocol. In other embodiments, the methods and apparatus of the present invention can be used in a CDMA only system, or in a system using a time division multiplexing/FDMA and time division multiplexing/CDMA. In one embodiment, the spread data streams are transmitted in timeslots (, FIG.) and frequencies (, FIG.) that are interspersed between timeslots and frequencies used for the high rate data. A receiver (, FIG.) performs complementary demodulation (, FIG.), demultiplexing (, FIG.), and decoding (, FIG.).

Methods and apparatus for providing multiple wireless communication services having different bit rates

A method of increasing satellite communication quality by using a MEO satellite constellation ( ) and a LEO satellite constellation ( ) in combination with a decision algorithm which selects the appropriate constellation to route a communication signal through. The decision algorithm can be embodied in three ways: gateway based ( ), individual subscriber unit based ( ) and satellite based ( ). The MEO constellation ( ) and LEO ( ) constellation may be cross-linked, allowing for switching of service between satellites, as needed, during a communication session.

System for providing optimal satellite communication via a MEO/LEO satellite constellation

A satellite-based communications system ( ) includes a communication satellite ( ) using a Time Division Duplex (TDD) frame structure. The communication satellite ( ) transmits first data ( ) during a first sub-frame ( ) and receives second data ( ) during a second sub-frame ( ) of a time division multiple access (TDMA) frame ( ). A terrestrial repeater ( ) receives the first data ( ) using a first link ( ) during the first sub-frame ( ), delays the first data ( ) by a sub-frame duration, and transmits the first data ( ) to a subscriber unit ( ) using a second link ( ). The terrestrial repeater ( ) receives the second data ( ) from the subscriber unit ( ) using the second link ( ), delays the second data ( ) by the sub-frame duration, and transmits the second data ( ) using the first link ( ) to the satellite ( ) during the second sub-frame ( ).

Satellite-based communications system with terrestrial repeater and method therefor

A beam control subsystem ( , FIG. ) provides acquisition, synchronization, and traffic beams ( , FIG. ) to communication devices ( ) within a footprint ( ) of a system node ( ), where each beam comprises a set of beamlets ( ). The subsystem ( , FIG. ) first acquires ( , FIG. ) and synchronizes ( , FIG. and FIG. ) with each communication device. Acquisition involves selecting ( , FIG. ) and combining ( ) sets of beamlets ( , FIG. ), and determining whether any devices within the sets are attempting to acquire the system. If so, synchronization is performed by varying ( , FIG. ) beamlet weighting coefficients to find, based on modem feedback, a combination of coefficients that yields a maximum signal-to-interference&plus;noise ratio for multiple users within a beam. The communication device is then handed off ( ) to a traffic beam. The subsystem ( ) continues, based on modem feedback, to adapt ( , FIG. ) beamlet weighting coefficients in order to track the traffic beam in a manner that provides the maximum SINR.

Method and apparatus for controlling communication beams within a cellular communication system

A time division multiple access (TDMA) communications system ( ) includes a first TDMA platform ( ) for transmitting a call ( ) over a circuit switched communication link ( ) to a second TDMA platform ( ). The call ( ) exhibits a first signal type ( ) and second signal type ( ). A controller ( ) establishes a capacity allocation ( ) responsive to the first signal type ( ) for the communication link ( ). When the call ( ) exhibits the first signal type ( ), the first TDMA platform ( ) transmits first packets ( ) of the call ( ) in a first packet format ( ) using the capacity allocation ( ), and when the call ( ) exhibits the second signal type ( ), the first TDMA platform ( ) transmits second packets ( ) of the call ( ) in a second packet format ( ) using the capacity allocation ( ).

Call management in a TDMA system through variable packet formatting

The present invention utilizes a dual polarization reception system ( ) that utilizes the energy available in orthogonal polarizations to effectively increase link margin, thereby allowing for adequate signal quality reception in difficult environments. A co-polarized and a cross-polarized signal are separately downconverted and demultiplexed. The signals from each demultiplexed output are then sampled and weighted. The weighted samples for each polarity are combined in soft decision combining/decoding circuitry ( ), and this circuitry determines the most likely state of a received symbol's transmitted value.

A satellite communication system uses dual satellite coverage techniques to simulate the provision of full duplex communications in the system. Each subscriber ( ) in the system communicates with two satellites ( ) that use complementary time division duplex (TDD) frame structures ( ) for communicating with the subscriber ( ). In one embodiment, each satellite in the system performs a transition between a first TDD frame structure ( ) and a second TDD frame structure ( ) while travelling through a transition region ( ) of an associated orbit ( ). Preferably, the transition is performed gradually so that an abrupt reduction in system capacity is avoided. In another embodiment, individual orbital planes in the satellite system are dedicated for use with particular TDD frame structures. A subscriber thus communicates with one satellite in each of two planes during a connection.

System and method for providing dual satellite communications coverage

A method and apparatus for soft decision propagation trades off system bandwidth in return for link margin. When signal quality on an uplink is low, a satellite ( ) sends soft decision data, rather than hard decision data, to a gateway ( ). When path diversity exists on the uplinks, and multiple satellites ( ) receive the uplink, multiple versions of soft decision data are sent to the gateway ( ). The gateway combines the soft decision data resulting from multiple uplink paths, thereby increasing the effective uplink signal to noise ratio.

Method and system for soft decision propagation

A method and apparatus are provided for operating a phased-array antenna (,) on a satellite-based communications node (,) in more than one mode by controlling the number of beam-forming elements and by applying appropriate phase-control and/or amplitude-control coefficients to the selected elements. The antenna can be operated as a diffused-beam antenna at a relatively low data rate, enabling the satellite-communications node (,) to communicate with a first terrestrial communications node (,). The antenna can also be operated to generate multiple focused-beam antenna patterns each communicating at a relatively high data rate, enabling the satellite-communications node (,) to communicate with a different terrestrial communications node (,) by changing the amplitude and/or the phase coefficients as well as the number of beam-forming elements.

System and method for multi-mode operation of satellite phased-array antenna

In a code division multiplexed system, a subscriber unit (,, FIG.,), which includes a pseudonoise code generator (,), is synchronized with the pseudonoise code generator (,) of a communications node (,). Synchronization between the pseudonoise code generators (,) is achieved through measuring the time delay of a signal transmitted from the communications node (,) to the subscriber unit (,) and advancing the code generator of the subscriber unit in accordance with the time delay. This permits transmissions from the subscriber unit (,) to be received synchronously at the satellite. The synchronization is maintained through the periodic transmission from the communications node (,) to the subscriber unit (,) of a message which commands the subscriber unit (,) to adjust the timing of its pseudonoise code generator. The resulting synchronous code division multiplexed system offers increased capacity over conventional systems.

Growing community of inventors

Silver Spring, MD, United States of America

Robert Anthony Peters