Allocation of subframes for uplink and downlink transmission in TDD-LTE

• US 8,553,639 B2
• Filed: 02/07/2012
• Issued: 10/08/2013
• Est. Priority Date: 02/07/2012
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Acharya, Joydeep, Gao, Long, Gaur, Sudhanshu
• Primary Examiner(s): HAN, CLEMENCE S
• Application Number:
  US13/368,264
• Publication Number:
  US 20130201864A1
• Time in Patent Office: 609 Days
• Field of Search: None
• US Class Current: 370/329
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/52 based on load

Abstract

Systems and methods are directed to deciding the number of subframes in a frame to use for uplink transmission, with the remaining frames used for downlink transmission for a Base Station (BS) in a Time Division Duplexing Long Term Evolution (TDD-LTE). Systems and methods are based on the number of User Equipment (UEs) that the BS has to serve in the uplink and in the downlink, as well as the uplink (UL) and downlink (DL) traffic loads per user. Systems and methods are directed to allowing a TDD LTE BS to partition the subframes in a frame for its UL and DL traffic.

Claims

1. A base station, comprising:

an information processing module that determines a number of uplink user equipments (UEs) handled by the base station, and a number of downlink UEs handled by the base station;

a calculation module that determines a metric calculation based on the determined number of uplink UEs and the determined number of downlink UEs; and

a frame formatting module that adjusts a number of subframes within a frame based on the determined metric calculation.

2. The base station of claim 1, wherein the calculation module determines the metric calculation based on a ratio of an uplink traffic load to a downlink traffic load.

3. The base station of claim 1, wherein the calculation module determines the metric calculation based on a ratio of the determined number of uplink UEs to a combination of the determined number of uplink UEs and the determined number of downlink UEs when a simplified metric is utilized.

4. The base station of claim 1, wherein the calculation module determines the metric calculation based on a ratio of the determined number of uplink UEs weighted by a ratio of an uplink traffic load to a downlink traffic load, to a combination of the weighted determined number of uplink UEs and the determined number of downlink UEs when a simplified metric is not utilized.

5. The base station of claim 1, wherein the calculation module determines when a simplified metric is utilized based on rate of change of a ratio of an uplink traffic load to a downlink traffic load.

6. The base station of claim 1, wherein the calculation module determines when a simplified metric is utilized based on an accuracy of received UE measurements.

7. A method of operating a base station, comprising:

determining a number of uplink user equipments (UEs) handled by the base station and a number of downlink UEs handled by the base station;

determining a metric calculation based on the determined number of uplink UEs, and the determined number of downlink UEs; and

adjusting a number of subframes within a frame based on the determined metric calculation.

8. The method of claim 7, wherein the determining the metric calculation is based on a ratio of an uplink traffic load to a downlink traffic load.

9. The method of claim 7, wherein the determining the metric calculation is based on a ratio of the determined number of uplink UEs to a combination of the determined number of uplink UEs and the determined number of downlink UEs when a simplified metric is utilized.

10. The method of claim 7, wherein the determining the metric calculation is based on a ratio of the determined number of uplink UEs weighted by a ratio of an uplink traffic load to a downlink traffic load, to a combination of the weighted determined number of uplink UEs and the determined number of downlink UEs when a simplified metric is not utilized.

11. The method of claim 7, further comprising determining when a simplified metric is utilized based on rate of change of a ratio of an uplink traffic load to a downlink traffic load.

12. The method of claim 7, further comprising determining when a simplified metric is utilized based on an accuracy of received UE measurements.

13. A non-transitory computer readable medium, having stored therein a program for making a computer execute a method for operating a base station, the program including computer executable instructions for performing steps comprising:

determining a number of uplink user equipments (UEs) handled by the base station and a number of downlink UEs handled by the base station;

determining a metric calculation based on the determined number of uplink UEs, and the determined number of downlink UEs; and

adjusting a number of subframes within a frame based on the determined metric calculation.

14. The non-transitory computer readable medium of claim 13, wherein the determining the metric calculation is based on a ratio of an uplink traffic load to a downlink traffic load.

15. The non-transitory computer readable medium of claim 13, wherein the determining the metric calculation is based on a ratio of the determined number of uplink UEs to a combination of the determined number of uplink UEs and the determined number of downlink UEs when a simplified metric is utilized.

16. The non-transitory computer readable medium of claim 13, wherein the determining the metric calculation is based on a ratio of the determined number of uplink UEs weighted by a ratio of an uplink traffic load to a downlink traffic load, to a combination of the weighted determined number of uplink UEs and the determined number of downlink UEs when a simplified metric is not utilized.

17. The non-transitory computer readable medium of claim 13, wherein the instructions further comprise determining when a simplified metric is utilized based on rate of change of a ratio of an uplink traffic load to a downlink traffic load.

18. The non-transitory computer readable medium of claim 13, wherein the instructions further comprise determining when a simplified metric is utilized based on an accuracy of received UE measurements.