System and method for coordinated spatial multiplexing using second order statistical information
First Claim
1. A method for controller operations, the method comprising:
- receiving second order statistics from a plurality of communications devices;
computing a beamforming vector for each communications device in the plurality of communications devices, wherein the beamforming vector for a communications device is based on the second order statistics provided by the communications device;
selecting a subset of communications devices from the plurality of communications devices to receive transmissions; and
transmitting transmissions to the selected subset of communications devices, wherein the transmitting uses the computed beamforming vector for each selected communications device to transmit the transmissions to the selected communications device,wherein the plurality of communications devices comprises two communications devices,wherein computing a beamforming vector comprises maximizing a sum-rate capacity for each of the two communications devices, andwherein the sum-rate capacity for the two communications devices is expressible as;
C=log2(1+SNR1)+log2(1+SNR2)where SNRi is a signal-to-noise ratio for an i-th communications device.
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Abstract
A system and method for coordinated spatial multiplexing using second order statistical information is provided. A method for controller operations includes receiving second order statistics from a plurality of communications devices, computing a beamforming vector for each communications device in the plurality of communications devices, selecting a subset of communications devices from the plurality of communications devices to receive transmissions, and transmitting transmissions to the subset of selected communications devices. The beamforming vector for a communications device is based on the second order statistics provided by the communications device, and the transmitting uses the computed beamforming vector for each selected communications device to transmit the transmissions to the selected communications device.
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Citations
14 Claims
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1. A method for controller operations, the method comprising:
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receiving second order statistics from a plurality of communications devices; computing a beamforming vector for each communications device in the plurality of communications devices, wherein the beamforming vector for a communications device is based on the second order statistics provided by the communications device; selecting a subset of communications devices from the plurality of communications devices to receive transmissions; and transmitting transmissions to the selected subset of communications devices, wherein the transmitting uses the computed beamforming vector for each selected communications device to transmit the transmissions to the selected communications device, wherein the plurality of communications devices comprises two communications devices, wherein computing a beamforming vector comprises maximizing a sum-rate capacity for each of the two communications devices, and wherein the sum-rate capacity for the two communications devices is expressible as;
C=log2(1+SNR1)+log2(1+SNR2)where SNRi is a signal-to-noise ratio for an i-th communications device. - View Dependent Claims (2, 3, 4, 5)
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6. A method for communications device operations, the method comprising:
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estimating a communications channel between the communications device and a controller; estimating second order statistics for the communications channel based on the estimated communications channel; transmitting the second order statistics to the controller, wherein the second order statistics are used by the controller to compute a beamforming vector to be used in communications to the communications device; and receiving a transmission that uses the computed beamforming vector, wherein the communications device is communicating with two controllers using multi-terminal coordinated spatial multiplexing, and wherein estimating the second order statistics comprises, evaluating
R11=E[h11h21H] and R21=E[h21h21H],where Rij is the second order statistics for a i-th communications device from an j-th controller, hij is a communications channel between the j-th controller and the i-th communications device, hijH is the Hermitian of hij, and E[.] is an expected value function. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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14. A method for communications device operations, the method comprising:
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estimating a communications channel between the communications device and a controller; estimating second order statistics for the communications channel based on the estimated communications channel, wherein the second order statistics comprise a spatial covariance matrix; transmitting the second order statistics to the controller, wherein the second order statistics are used by the controller to compute a beamforming vector to be used in communications to the communications device; and receiving a transmission that uses the computed beamforming vector, wherein estimating the second order statistics comprises evaluating
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Specification