The Directv Group, Inc.

The Boeing Company

Hughes Electronics Corporation

Alan Cha

Donald C D Chang

Ying J Feria

Frank A Hagen

Ming U Chang

Weizheng W Wang

Kar W Yung

Arun K Bhattacharyya

Jacqueline C Chen

Donald C Chang

James P McKay

A communication system has a stratospheric platform with a payload controller and a phased array antenna having a plurality of main array elements for generating a plurality of communication beams and a plurality of auxiliary elements for canceling interference between the communication beams. A gateway station communicates with the stratospheric platform. The gateway station scales the plurality of elements to form a reconfigurable plurality of beams. The gateway station communicates an embedded control signal to the stratospheric platform to communicate a scaling of elements to form the communication beams and the auxiliary element output. The auxiliary element output is used to provide interference canceling.

Stratospheric-based communication system for mobile users using additional phased array elements for interference rejection

A communication system has a stratospheric platform with a payload controller and a phased array antenna having a plurality of main array elements for generating a plurality of communication beams and a plurality of auxiliary elements for canceling interference between the communication beam. A gateway station communicates with the stratospheric platform. The gateway station scales the plurality of elements to form a reconfigurable plurality of beams. The gateway station communicates an embedded control signal to the stratospheric platform to communicate a scaling of elements to form the communication beams and the auxiliary element output. The auxiliary element output is used to provide interference canceling.

A method for rapid acquisition of a specific subscriber by a ground-based beamformer includes the steps of defining a coverage area as an arrangement of a plurality of cells wherein one of the plurality of cells includes a specific subscriber; defining a partition of cell clusters wherein one of the cell clusters includes the one of the plurality of cells that includes the specific subscriber; forming a beam that corresponds to an area of one of the cell clusters; and scanning the beam to the cell cluster that includes the specific subscriber.

Rapid user acquisition by a ground-based beamformer

A method for communicating between a user terminal and multiple stratospheric transponder platforms includes the steps of positioning a plurality of stratospheric transponder platforms () in a substantially fixed position () with respect to a user terminal antenna () coupled to a user terminal () and communicating between the user terminal () and at least two of the plurality of stratospheric transponder platforms () concurrently.

Concurrent communications between a user terminal and multiple stratospheric transponder platforms

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 system has a stratospheric platform with a payload controller and a phased array antenna having a plurality of elements. A gateway station communicates with the stratospheric platform. The gateway station scales the plurality of elements to form a reconfigurable plurality of beams. The gateway station communicates a control signal to the stratospheric platform to communicate a scaling of the elements. The stratospheric platform configures the elements of the phased array antenna according to the scaling using adaptive interference rejection. The gateway station has an adaptive beam processor coupled to user position files. The adaptive beam processor with the user position data can adaptively cancel interference from other beams.

Stratospheric-based communication system for mobile users having adaptive interference rejection

A communications system and method of operating the communications system includes a high altitude communication device that communicates with a plurality of user terminals and a gateway station. The gateway station couples the users to terrestrial networks and other users. The high altitude communication device has gateway station that assigns a first code to a beam of a first plurality of users. The gateway station continually determines whether an interference occurs between the first beam and the second beam by determining whether the first interference contour intersects the second interference contour when the first interference contour intersects the second interference contour. The gateway station declares an interference when the contours intersect and reassigns a second resource to the first beam.

Resource assignment system and method for determining the same

A communication system including a first transceiver located on a first platform at a predetermined altitude. A first antenna is located on the first platform and connected to the first transceiver. A second antenna is connected to the other end of the first transceiver. A second transceiver is located on a ground hub physically and independent of the first platform. A third antenna is located on the ground hub and connected to the second transceiver. The third antenna is adapted to communicate with the second antenna. The first platform is maintained in a stratospheric orbit. A beamforming system is connected to the second transceiver and mounted on the ground hub. The beamforming system provides a beamformed signal from the second transceiver to the first transceiver effective to drive the first array antenna to radiate multiple beams to a surface, whereby the multiple beams create time varying and dissimilar footprints thereon. A second antenna is mounted on the first platform to receive the beamformed signal from the ground hub. The beamforming system is adapted to drive the first antenna to generate plural beams on the earth's surface, each beam providing a respective footprint or cell. Each beam tracks a respective user located at a center of each cell. The system allows for narrow beams to be created which, in turn, enables frequency reuse. A code is assigned to each beam and a mechanism is provided for preventing a user from receiving more than one beam with a given code. This mechanism is adapted to anticipate a condition by which a user will move to a location at which the user would receive more than one beam with a given code. The mechanism will quickly assign a second code to at least one beam prior to the arrival of the user at that position.

Stratospheric platforms based mobile communications architecture

A communication system has a high altitude communication device generating a plurality of user link beams having a first communication characteristic and a feeder link having a first communication characteristic. A gateway terminal receives the user link beam. A user terminal receives at least one of the user link beams. The plurality of user link beams comprises a first user link beam within a first cell and a first isolation zone outside the first cell. The plurality of user link beams comprises a second user link beam having the first communication characteristic and positioned within a second cell and a second isolation zone outside said second cell. The second isolation zone overlaps the first isolation zone. The feeder link is positioned within the first isolation zone and the second isolation zone. The feeder link has the first communication characteristic.

Architecture utilizing frequency reuse in accommodating user-link and feeder-link transmissions

A patch antenna is disclosed having four ports for circular polarization that suppress the TM-02 mode, resulting in a radiation pattern that is symmetric. The axial ratio performance is consequently superior to that of two-port patch antennas. A four-port patch antenna includes a patch made of an electrically conductive material, a patch substrate coupled to the patch wherein the patch substrate is made of a dielectric material, a ground plane coupled to the patch substrate wherein the ground plane is made of an electrically conductive material having at least four slots formed therein, a feed substrate coupled to the ground plane wherein the feed substrate is made of a dielectric material, and a hybrid network coupled to the feed substrate that includes a right hand circularly polarized port, a left hand circularly polarized port, and two matched terminated ports.

Four-port patch antenna

A dual-band patch antenna element ( ) for circular or linear polarization. The patch element ( ) is excited by two different hybrids ( ), designed for transmit and receive bands respectively. Each hybrid ( ) electromagnetically couples a pair of orthogonal ground plane slots ( ) that excite the patch antenna ( ). The hybrid ( ) and slot ( ) dimensions for the transmit band are different from the hybrid ( ) and slot ( ) dimensions for the receive band. Isolation can be improved by connecting shunt stubs ( ) to the hybrids ( ).

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Glendale, CA, United States of America

Alan Cha