System and Method for Adaptive Beamforming Communication

• US 20190013847A1
• Filed: 07/07/2017
• Published: 01/10/2019
• Est. Priority Date: 07/07/2017
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Kim, Kyeong Jin, Orlik, Philip
• Granted Patent: US 10,355,762 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams

Abstract

A wireless communication system includes a controller to control a plurality of antenna subarrays of a first wireless communication device to form a plurality of directional beams to communicate a beamformed diversity wireless transmission between the first wireless communication device and a set of second wireless communication devices over a plurality of communication channels. The controller assigns at least some antenna subarrays to at least some second wireless communication devices using a greedy optimization with a relaxation parameter and controls the plurality of antenna subarrays according to the assignment.

Claims

1. A wireless communication system, comprising:

a controller to control a plurality of antenna subarrays of a first wireless communication device to form a plurality of directional beams to communicate a beamformed diversity wireless transmission between the first wireless communication device and a set of second wireless communication devices over a plurality of communication channels, wherein the controller assigns at least some antenna subarrays to at least some second wireless communication devices using a greedy optimization with a relaxation parameter and controls the plurality of antenna subarrays according to the assignment.

2. The system of claim 1, wherein a number of assignment choices preserved at some stage of the greedy optimization equals the value of the relaxation parameter M to form an M-best set of assignment combinations, wherein the assignment choices are preserved, avoiding collision between devices, based on a total performance metric of the assignment combinations formed with the preserved assignment choices.

3. The system of claim 2, wherein the performance metric includes one or combination of a channel capacity metric, a rate for each communication channel in the assignment combination, a signal-to-noise (SNR) value for each communication channel in the assignment combination, a signal-to-interference-plus-noise-ratio (SINR) value for each communication channel in the assignment combination.

4. The system of claim 2, wherein the value M for the greedy optimization is selected based on a computational power of the controller.

5. The system of claim 2, wherein the value M for the greedy optimization is selected based on a number of the second wireless communication devices.

6. The system of claim 2, wherein the value M for the greedy optimization is proportional to at least one or a combination of a number of the second wireless communication devices and a number of antenna subarrays.

7. The system of claim 6, wherein the proportionality between the value M for the greedy optimization and the number of the second wireless communication devices is non-linear.

8. The system of claim 1, wherein the controller is configured to

determine a signal-to-noise (SNR) value for communication channels connecting each second wireless communication device with each subarray of antennas;

determine a set of assignment combinations, wherein an SNR/rate metric of each assignment combination is a function of SNR values of communication channels in the assignment combination, wherein the set of assignment combination is determined iteratively until a termination condition is met, wherein an iteration comprises;

select a second wireless communication device from the set of second wireless communication devices;

combine the set of assignment combinations determined during a previous iteration with each possible assignment of the second wireless communication device to different subarrays of antennas to produce an extended set of assignment combinations;

determine the SNR metric for each assignment combination in the extended set of assignment combinations;

select, from the extended set of assignment combinations, a subset of assignment combinations to be used as the set of assignment combinations at a subsequent iteration, wherein each assignment combination in the subset has the SNR metric equals or greater than the SNR metric of an assignment combination remaining in the extended set, wherein the maximal size of the subset is the same for all iterations;

select an assignment combination from the set of assignment combinations with the largest sum of the SNR metric; and

transmit data from the set of subarrays of antennas to the set of second wireless communication devices according the selected assignment combination.

9. The system of claim 1, wherein the beamformed diversity wireless transmission comprises a transmission over one or combination of a millimeter wave (mmWave) channel and a directional multi-gigabit (DMG) channel.

10. The system of claim 1, further comprising

one or more antenna arrays controllable as the plurality of antenna subarrays;

and

a plurality of Radio Frequency (RF) chains coupled to the plurality of antenna subarrays and the controller, such that the controller controls the plurality of antenna subarrays through the RF chains.

12. The method of claim 1, wherein a number of assignment choices preserved at some stage of the greedy optimization equals the value of the relaxation parameter M to form an M-best set of assignment combinations, wherein the assignment choices are preserved based on a total performance metric of the assignment combinations formed with the preserved assignment choices.

13. The method of claim 12, wherein the performance metric includes one or combination of a channel capacity metric, a signal-to-noise (SNR) value for each communication channel in the assignment combination, a signal-to-interference-plus-noise-ratio (SINR) value for each communication channel in the assignment combination.

14. The method of claim 12, wherein the value M for the greedy optimization is selected based on a computational power of the controller.

15. The method of claim 12, wherein the value M for the greedy optimization is selected based on a number of the second wireless communication devices.

16. The method of claim 12, wherein the value M for the greedy optimization is proportional to at least one or a combination of a number of the second wireless communication devices and a number of antenna subarrays.

17. The method of claim 16, wherein the proportionality between the value M for the greedy optimization and the number of the second wireless communication devices is non-linear.

11. A method for beamformed diversity wireless transmission between a first wireless communication device and a set of second wireless communication devices over a plurality of communication channels, wherein the method uses a processor coupled with stored instructions implementing the method, wherein the instructions, when executed by the processor carry out at least some steps of the method, comprising:

determining an assignment combination between a plurality of antenna subarrays of the first wireless communication device and the set of second wireless communication devices using a greedy optimization with a relaxation parameter optimizing a performance metric of the beamformed diversity wireless transmission; and

controlling the plurality of antenna subarrays of the first wireless communication device to form a plurality of directional beams to communicate the beamformed diversity wireless transmission between the first wireless communication device and the set of second wireless communication devices according to the assignment combination.

18. The method of claim 11, wherein determining the assignment combination comprises:

determining a signal-to-noise (SNR) value for communication channels connecting each second wireless communication device with each subarray of antennas;

determining a set of assignment combinations, wherein an SNR metric of each assignment combination is a function of SNR values of communication channels in the assignment combination, wherein the set of assignment combination is determined iteratively until a termination condition is met, wherein an iteration comprises;

selecting a second wireless communication device from the set of second wireless communication devices;

combining the set of assignment combinations determined during a previous iteration with each possible assignment of the second wireless communication device to different subarrays of antennas to produce an extended set of assignment combinations;

determining the SNR metric for each assignment combination in the extended set of assignment combinations;

selecting, from the extended set of assignment combinations, a subset of assignment combinations to be used as the set of assignment combinations at a subsequent iteration, wherein each assignment combination in the subset has the SNR metric equals or greater than the SNR metric of an assignment combination remaining in the extended set, wherein the maximal size of the subset is the same for all iterations; and

selecting an assignment combination from the set of assignment combinations with the largest sum of the SNR metric.

19. A product including a non-transitory storage medium having stored thereon instructions that, when executed by a machine, result in:

determining an assignment combination between a plurality of antenna subarrays of the first wireless communication device and the set of second wireless communication devices using a greedy optimization with a relaxation parameter optimizing a performance metric of the beamformed diversity wireless transmission; and

controlling the plurality of antenna subarrays of the first wireless communication device to form a plurality of directional beams to communicate the beamformed diversity wireless transmission between the first wireless communication device and the set of second wireless communication devices according to the assignment combination.

20. The product of claim 19, wherein determining the assignment combination comprises:

determining a signal-to-noise (SNR) value for communication channels connecting each second wireless communication device with each subarray of antennas;

determining a set of assignment combinations, wherein an SNR metric of each assignment combination is a function of SNR values of communication channels in the assignment combination, wherein the set of assignment combination is determined iteratively until a termination condition is met, wherein an iteration comprises;

selecting a second wireless communication device from the set of second wireless communication devices;

combining the set of assignment combinations determined during a previous iteration with each possible assignment of the second wireless communication device to different subarrays of antennas to produce an extended set of assignment combinations;

determining the SNR metric for each assignment combination in the extended set of assignment combinations;

selecting, from the extended set of assignment combinations, a subset of assignment combinations to be used as the set of assignment combinations at a subsequent iteration, wherein each assignment combination in the subset has the SNR metric equals or greater than the SNR metric of an assignment combination remaining in the extended set, wherein the maximal size of the subset is the same for all iterations; and

selecting an assignment combination from the set of assignment combinations with the largest sum of the SNR metric.