Managing analog beams in mmWave networks

• US 10,292,059 B2
• Filed: 01/18/2018
• Issued: 05/14/2019
• Est. Priority Date: 01/20/2017
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Khojastepour, Mohammad, Prasad, Narayan, Rangarajan, Sampath, Ghasempour, Yasaman
• Primary Examiner(s): Torres, Marcos L
• Application Number:
  US15/874,016
• Publication Number:
  US 20180213415A1
• Time in Patent Office: 481 Days
• CPC Class Codes: H04B 7/02 Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas RAKE receivers H04B1/7115
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource

Abstract

A computer-implemented method executed in a wireless communication system for establishing communication links in a millimeter wave network is presented. The method includes determining active communication links between a plurality of transmitters and a plurality of receivers operated by a plurality of users and formulating a quality of service (QoS) proportional fairness (PF) network utility as a constrained submodular set function maximization problem. The method further includes performing an optimization framework by optimizing, based on the active communication links, user association for fixed transmit beam patterns and optimizing, based on the active communication links, the fixed transmit beam patterns and corresponding beam attributes for a fixed set of user associations. The method also includes iteratively performing the optimizing steps in an alternating manner to determine a user from the plurality of users that optimizes the constrained submodular set function maximization problem and assigning the determined user to a cell.

Claims

1. A computer-implemented method executed in a wireless communication system for establishing communication links in a millimeter wave (mmWave) network, the method comprising:

determining active communication links between a plurality of transmitters and a plurality of receivers operated by a plurality of users;

expressing a quality of service (QoS) proportional fairness (PF) network utility as a constrained submodular set function maximization problem to manage user association between the plurality of users by employing a distributed algorithm to solve the constrained submodular set function maximization problem;

determining an optimal user association between the plurality of users by executing the distributed algorithm to;

optimize, based on the active communication links, user association for fixed transmit beam patterns; and

optimize, based on the active communication links, the fixed transmit beam patterns and corresponding beam attributes for a fixed set of user associations;

iteratively performing the optimizing steps in an alternating manner to determine a user from the plurality of users that approximately maximizes the constrained submodular set function maximization problem to guarantee convergence to an absorbing state; and

assigning the determined user to a cell.

2. The method of claim 1, wherein the beam attributes include at least duty cycles and power allocations.

3. The method of claim 2, wherein the plurality of transmitters are transmission points (TPs) and the plurality of receivers are devices of the plurality of users.

4. The method of claim 3, wherein a sum of non-negative fractions for each of the TPs and beam combinations does not exceed unity.

5. The method of claim 3, wherein a sum of the duty cycles across all activated beams in any of the TPs does not exceed a number of transmit radiofrequency (RF) chains.

6. The method of claim 3, wherein sets of duty cycles and power levels at any of the TPs are selected to be compatible with each other.

7. The method of claim 3, wherein minimum rate constraints are imposed for each of the plurality of users.

8. The method of claim 7, wherein each of the plurality of users is permitted to be served by any one of the TPs by using any one beam.

9. The method of claim 1, wherein capacity of the beam patterns is proportional to the beam attributes.

10. A wireless communication system for establishing communication links in a millimeter wave (mmWave) network, the system comprising:

a memory; and

a processor in communication with the memory, wherein the processor is configured to;

determine active communication links between a plurality of transmitters and a plurality of receivers operated by a plurality of users;

express a quality of service (QoS) proportional fairness (PF) network utility as a constrained submodular set function maximization problem to manage user association between the plurality of users by employing a distributed algorithm to solve the constrained submodular set function maximization problem;

determining an optimal user association between the plurality of users by executing the distributed algorithm to;

optimize, based on the active communication links, user association for fixed transmit beam patterns; and

optimize, based on the active communication links, the fixed transmit beam patterns and corresponding beam attributes for a fixed set of user associations;

iteratively perform the optimizing steps in an alternating manner to determine a user from the plurality of users that approximately maximizes the constrained submodular set function maximization problem to guarantee convergence to an absorbing state; and

assign the determined user to a cell.

11. The system of claim 10, wherein the beam attributes include at least duty cycles and power allocations.

12. The system of claim 11, wherein the plurality of transmitters are transmission points (TPs) and the plurality of receivers are devices of the plurality of users.

13. The system of claim 12, wherein a sum of non-negative fractions for each of the TPs and beam combinations does not exceed unity.

14. The system of claim 12, wherein a sum of the duty cycles across all activated beams in any of the TPs does not exceed a number of transmit radiofrequency (RF) chains.

15. The system of claim 12, wherein sets of duty cycles and power levels at any of the TPs are selected to be compatible with each other.

16. The system of claim 12, wherein minimum rate constraints are imposed for each of the plurality of users.

17. The system of claim 16, wherein each of the plurality of users is permitted to be served by any one of the TPs by using any one beam.

18. The system of claim 10, wherein capacity of the beam patterns is proportional to the beam attributes.

19. A non-transitory computer-readable storage medium comprising a computer-readable program for establishing communication links in a millimeter wave (mmWave) network, wherein the computer-readable program when executed on a computer causes the computer to perform the steps of:

determining active communication links between a plurality of transmitters and a plurality of receivers operated by a plurality of users;

expressing a quality of service (QoS) proportional fairness (PF) network utility as a constrained submodular set function maximization problem to manage user association between the plurality of users by employing a distributed algorithm to solve the constrained submodular set function maximization problem;

determining an optimal user association between the plurality of users by executing the distributed algorithm to;

optimize, based on the active communication links, user association for fixed transmit beam patterns; and

optimize, based on the active communication links, the fixed transmit beam patterns and corresponding beam attributes for a fixed set of user associations;

iteratively performing the optimizing steps in an alternating manner to determine a user from the plurality of users that approximately maximizes the constrained submodular set function maximization problem to guarantee convergence to an absorbing state; and

assigning the determined user to a cell.

20. The non-transitory computer-readable storage medium of claim 19, wherein the beam attributes include at least duty cycles and power allocations.