Uplink user equipment selection

• US 10,735,057 B1
• Filed: 04/29/2019
• Issued: 08/04/2020
• Est. Priority Date: 04/29/2019
• Status: Active Grant

• Current Assignee: Virewirx Incorporated
• Original Assignee: XCOM Labs, Inc.
• Inventors: Zhao, Wanlun, Chen, Jinghu, Kadous, Tamer Adel, Fan, Michael Mingxi, Black, Peter John
• Primary Examiner(s): Patel, Dhaval V
• Application Number:
  US16/397,958
• Time in Patent Office: 463 Days
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

Aspects of the disclosure relate to a selection scheme implemented by a scheduler in a multiple-input multiple-output (MIMO) network to identify which users to schedule simultaneously during the same time slot. For uplink communications and a particular frequency wholeband or sub-band, the scheduler can obtain uplink channel information for channels between base stations and UEs. The scheduler can then determine a strength of the channels using the uplink channel information, order the UEs using a fairness metric based on the channel strengths, and compute one or more QR decompositions to identify whether a spatial dimension of a UE is roughly or approximately orthogonal to spatial dimension(s) of other UEs selected to be served during a time slot being scheduled. If the spatial dimensions are roughly or approximately orthogonal, the scheduler selects the UE to be served at the same time as other UEs already selected.

Claims

1. A network system comprising:

a plurality of receive antenna elements of one or more serving nodes; and

a scheduler in communication with the plurality of receive antenna elements, the scheduler comprising a processor and computer-executable instructions, wherein the computer-executable instructions, when executed by the processor, cause the scheduler to;

obtain uplink channel information for channels between the plurality of receive antenna elements and a plurality of transmit antenna elements associated with a plurality of user equipment (UEs);

determine, for each transmit antenna element in the plurality, a channel strength based on the uplink channel information;

order the plurality of transmit antenna elements based on the determined channel strengths; and

in order from highest-ordered transmit antenna element to lowest-ordered transmit antenna element, select the respective transmit antenna element to communicate with one or more of the plurality of receive antenna elements during a first time slot in response to a determination that;

a measurement that represents a spatial orthogonality between the respective transmit antenna element and one or more spatial elements of one or more other transmit antenna elements in the plurality selected to communicate with one or more of the plurality of receive antenna elements is greater than a threshold value, and

a number of spatial dimensions provided by one or more transmit antenna elements in the plurality selected to communicate with one or more of the plurality of receive antenna elements does not exceed a number of receive antenna elements in the plurality of receive antenna elements.

2. The network system of claim 1, wherein the computer-executable instructions, when executed, further cause the scheduler to determine the threshold value based on channel coefficients of a channel associated with the highest-ordered transmit antenna element.

3. The network system of claim 2, wherein the computer-executable instructions, when executed, further cause the scheduler to determine the threshold value based on a constant value that is the same for all transmit antenna elements in the plurality.

4. The network system of claim 2, wherein the computer-executable instructions, when executed, further cause the scheduler to periodically determine the threshold value based on a constant value that changes based on a block error rate performance associated with at least one transmit antenna element in the plurality.

5. The network system of claim 2, wherein the computer-executable instructions, when executed, further cause the scheduler to determine the threshold value based on a constant value that is different for transmit antenna elements in the plurality.

6. The network system of claim 5, wherein the constant value for a first transmit antenna element in the plurality of transmit antenna elements is based on interference between the first transmit antenna element and one or more other transmit antenna elements in the plurality.

7. The network system of claim 1, wherein the computer-executable instructions, when executed, further cause the scheduler to obtain the uplink channel information for the channels from one or more of the plurality of transmit antenna elements.

8. The network system of claim 1, wherein the computer-executable instructions, when executed, further cause the scheduler to obtain the uplink channel information for the channels based on one or more uplink pilot signals.

9. The network system of claim 1, wherein the computer-executable instructions, when executed, further cause the scheduler to order the plurality of transmit antenna elements based on at least one of the determined channel strengths, latency priority, spectral efficiency, average throughput of the plurality of transmit antenna elements over a threshold period of time, or normalized throughput of the plurality of transmit antenna elements over the threshold period of time.

10. The network system of claim 1, wherein the computer-executable instructions, when executed, further cause the scheduler to select the respective transmit antenna element to communicate with one or more of the plurality of receive antenna elements for one of a resource block, two or more resource blocks, or a frequency band of a carrier.

11. A computer-implemented method comprising:

obtaining uplink channel information for channels between the plurality of receive antenna elements and a plurality of transmit antenna elements associated with a plurality of user equipment (UEs);

determining, for each transmit antenna element in the plurality, a channel strength based on the uplink channel information;

ordering the plurality of transmit antenna elements based on the determined channel strengths; and

in order from highest-ordered transmit antenna element to lowest-ordered transmit antenna element, selecting the respective transmit antenna element to communicate with one or more of the plurality of receive antenna elements during a first time slot in response to a determination that a measurement that represents a spatial orthogonality between the respective transmit antenna element and one or more spatial elements of one or more other transmit antenna elements in the plurality selected to communicate with one or more of the plurality of receive antenna elements is greater than a threshold value.

12. The computer-implemented method of claim 11, further comprising determining the threshold value based on channel coefficients of a channel associated with the highest-ordered transmit antenna element.

13. The computer-implemented method of claim 12, wherein determining the threshold value further comprises determining the threshold value based on a constant value that is the same for all transmit antenna elements in the plurality.

14. The computer-implemented method of claim 12, wherein determining the threshold value further comprises periodically determining the threshold value based on a constant value that changes based on a block error rate performance associated with at least one transmit antenna element in the plurality.

15. The computer-implemented method of claim 12, wherein determining the threshold value further comprises determining the threshold value based on a constant value that is different for transmit antenna elements in the plurality.

16. The computer-implemented method of claim 15, wherein the constant value for a first transmit antenna element in the plurality of transmit antenna elements is based on interference between the first transmit antenna element and one or more other transmit antenna elements in the plurality.

17. The computer-implemented method of claim 11, wherein obtaining uplink channel information further comprises obtaining the uplink channel information for the channels from one or more of the plurality of transmit antenna elements.

18. The computer-implemented method of claim 11, wherein obtaining uplink channel information further comprises obtaining the uplink channel information for the channels based on one or more uplink pilot signals.

19. The computer-implemented method of claim 11, wherein ordering the plurality of transmit antenna elements ordering the plurality of transmit antenna elements based on at least one of the determined channel strengths, latency priority, spectral efficiency, average throughput of the plurality of transmit antenna elements over a threshold period of time, or normalized throughput of the plurality of transmit antenna elements over the threshold period of time.

20. Non-transitory, computer-readable storage media comprising computer-executable instructions, wherein the computer-executable instructions, when executed by a scheduler in a baseband unit, cause the baseband unit to:

obtain uplink channel information for channels between the plurality of receive antenna elements and a plurality of transmit antenna elements associated with a plurality of user equipment (UEs);

determine, for each transmit antenna element in the plurality, a channel strength based on the uplink channel information;

order the plurality of transmit antenna elements based on the determined channel strengths; and

in order from highest-ordered transmit antenna element to lowest-ordered transmit antenna element, select the respective transmit antenna element to communicate with one or more of the plurality of receive antenna elements during a first time slot in response to a determination that a measurement that represents a spatial orthogonality between the respective transmit antenna element and one or more spatial elements of one or more other transmit antenna elements in the plurality selected to communicate with one or more of the plurality of receive antenna elements satisfies a threshold value.