US 6,556,809 B1 · Method and apparatus for controlling communication beams within a cellular communication system

Abstract

A beam control subsystem (200, FIG. 2) provides acquisition, synchronization, and traffic beams (142, FIG. 1) to communication devices (130) within a footprint (144) of a system node (110), where each beam comprises a set of beamlets (140). The subsystem (200, FIG. 2) first acquires (302, FIG. 3) and synchronizes (304, FIG. 3 and FIG. 6) with each communication device. Acquisition involves selecting (402, 416, FIG. 4) and combining (404) sets of beamlets (506, 510, FIG. 5), and determining whether any devices within the sets are attempting to acquire the system. If so, synchronization is performed by varying (604, FIG. 6) beamlet weighting coefficients to find, based on modem feedback, a combination of coefficients that yields a maximum signal-to-interference+noise ratio for multiple users within a beam. The communication device is then handed off (612, 614) to a traffic beam. The subsystem (200) continues, based on modem feedback, to adapt (802, 804, FIG. 8) beamlet weighting coefficients in order to track the traffic beam in a manner that provides the maximum SINR.

Claims12

Dependent claims

A method for digital beamforming in a cellular communication system comprising:

projecting a plurality of beamlets from a satellite of the cellular communication system;
combining a first set of the plurality of beamlets to form a single traffic beam that covers a geographical area having multiple communication devices communicating within the single traffic beam with the cellular communication system, the multiple communication devices within the single traffic beam are considered a first user group;
evaluating modem feedback of the satellite that is related to a signal-to-interference+noise ratio (SINR) of a signal received by the satellite from one or more of the multiple communication devices, wherein the one or more signals are received within the single traffic beam provided by the satellite;
adapting weighting coefficients applied to the first set of beamlets based upon the modem feedback of the satellite;
reviewing the weighting coefficients to determine whether, based on a change in user distribution over time, a second user group would result in improved quality of service for the multiple communication devices currently communicating within the single traffic beam;
and
if the change would result in the improved quality of service, regrouping the communication devices into the first user group and the second user group, and handing off the communication devices to traffic beams associated with the first user group and the second user group.

4 more elements

A method for digital beamforming in a cellular communication system comprising:

projecting a plurality of beamlets from a satellite of the cellular communication system;
combining a first set of the plurality of beamlets to form a single traffic beam that covers a geographical area having a communication device communicating with the cellular communication system;
evaluating modem feedback of the satellite that is related to a signal-to-interference+noise ratio (SINR) of signal received by the satellite from one or more communication devices, wherein the one or more signals are received within the single traffic beam provided by the satellite;
adapting weighting coefficients applied to the first set of beamlets based upon the modem feedback of the satellite;
prior to providing the single traffic beam to one of the one or more communication devices, providing a synchronization beam toward the one communication device, wherein the synchronization beam is formed from a second set of beamlets;
varying the weighting coefficients of the second set of beamlets to find a combination of weighting coefficients that results in a maximum SINR for the one communication device;
determining a location of the one communication device from the combination;
and
handing off the one communication device to a traffic beam that covers the location.

6 more elements

A method for digital beamforming in a cellular communication system comprising:

providing a plurality of beamlets from a satellite of the cellular communication system;
combining a first set of the plurality of beamlets to form an acquisition beam within a field of view of the satellite;
demodulating a signal received with the acquisition beam;
determining, from the signal, whether a communication device located within an area covered by the acquisition beam is attempting to acquire the cellular communication system;
if a communication device is attempting to acquire, entering a synchronization mode for that communication device, wherein the synchronization mode synchronizes with the communication device based on modern feedback;
reforming the acquisition beam from another set of beamlets;
and
repeating the demodulating, determining, entering, reforming, and repeating to identify other communication devices attempting to acquire the cellular communication system.

5 more elements

Dependencies are inferred from the claim text.

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

Life of this patent

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

Life of this patent

Abstract

Claims12