Motorola Corporation

Duke Edward Hanson

Thomas Peter Emmons, Jr

James William Startup

Jonathan Henry Gross

Peter Monsen

Robert Anthony Peters

Norbert Kleiner

John Richard Erlick

Shawn Wesley Hogberg

Joel Lloyd Gross

Scott C White

Isaac Eteminan

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

The present invention corrects for Doppler shift in both forward and reverse links in a cellular communications system including an airborne repeater. A reverse link pilot reference signal in a band similar to a communications signal band is received at a reverse link processor, and the Doppler shift in the reverse feeder link is corrected based on the reverse link pilot reference signal. The Doppler shift in the forward feeder link is also corrected based on the reverse link pilot reference signal prior to the forward feeder link being affected by the Doppler shift. The present invention also compensates for signal strength variations due to changing flight pattern positions of the repeater. Pre-compensation for forward feeder link path losses due to movement of the airplane is performed to cause communications signals transmitted to and from the cellular communications system repeater to have identical strength before the signals are transmitted to the system user cell phones within the area of coverage.

Doppler correction and path loss compensation for airborne cellular system

An airborne repeater antenna array ( ) in which beams transmitted from multiple antenna elements ( ) of the array to form terrestrial communications. cells are shaped according to predetermined system parameters. At least one of airplane telemetry data ( ) indicating an airplane flight pattern location, adjacent cellular system beam footprint data, and call distribution load within a terrestrial cell are received, and a complex gain is dynamically computed for each of the multiple antenna elements based on such data to thereby output a plurality of beams that form desired geographic communications coverage cells ( ).

Smart antenna for airborne cellular system

A communications unit determines that a wireless link between itself and a first communications network has degraded beyond acceptable limits (FIG. 2, ). The communications unit signals a second, unsynchronized, communications network during a pause in outgoing voice ( ) in order to acquire a channel and continue the call using the second network. When the second communications network indicates that sufficient resources are available, the communications unit transmits a Handover Trigger to the second network (FIG. 4, ). In response to the Handover Trigger, the first and second communications network establish a connection between each other ( ). When the connection has been established, the communications unit receives a channel assignment ( ) and continues the call using the resources of the second communications network.

Communications unit for seamless handover between networks and method of use therefor

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.

In a satellite communication system, beamforming is performed at baseband frequencies forming only beams which convey information. A received signal is applied to a downconverter (FIG. 1, 30), followed by a channelizer (50), and digital beamformer (60). The order of operations being reversed in order to generate a transmit beam. By performing the beamforming at baseband, the system can be allowed to form only those beams which convey information between a communications node and a subscriber. As a result, the system provides communication services to subscribers in a more cost-effective manner.

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Queen Creek, AZ, United States of America

Duke Edward Hanson