Power control in LTE-advanced heterogeneous networks

• US 9,066,303 B2
• Filed: 06/25/2012
• Issued: 06/23/2015
• Est. Priority Date: 06/25/2012
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Gao, Long, Acharya, Joydeep, Gaur, Sudhanshu
• Primary Examiner(s): LY, ANH VU H
• Application Number:
  US13/532,401
• Publication Number:
  US 20130343291A1
• Time in Patent Office: 1,093 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]

Abstract

Embodiments described herein are directed to a power control scheme for Long Term Evolution Advanced (LTE-A) heterogeneous networks to reduce the interference from macro base stations (BS) to pico user equipment (UE). The embodiments described herein may be used to develop LTE-A heterogeneous networks to balance the achievable throughput between macro and pico UEs and may thereby improve the overall system performance.

Claims

1. A pico base station, comprising:

a central processing unit (CPU) configured to;

generate interference distribution information for user equipment (UE) scheduling based on at least one power allocation pattern of a plurality of physical resource blocks (PRBs) associated with at least one macro base station; and

schedule at least one UE associated with the pico base station based on the interference distribution information.

2. The pico base station of claim 1, wherein the interference distribution information comprises a plurality of states indicative of one of a high interference state and a low interference state for each of the plurality of PRBs.

3. The pico base station of claim 2, wherein the CPU is further configured to determine a number of cell-edge UEs from the at least one UE associated with the pico base station for scheduling at a subframe having the low interference state, the number of the cell-edge UEs determined based on a reference signal received power (RSRP) from the pico base station.

4. The pico base station of claim 2, wherein the CPU is further configured to set ones of the plurality of states corresponding to ones of the plurality of PRBs to the high interference state if the transmit power of one of the plurality of PRBs from any received power allocation pattern corresponding to the ones of plurality of states is above a threshold, when more than one power allocation pattern is received indicating differing transmit powers for the respective ones of the plurality of PRBs.

5. The pico base station of claim 2, wherein the CPU is further configured to set ones of the plurality of states to the low interference state, if transmit powers of ones of the plurality of PRBs from all received power allocation patterns corresponding to the ones of the plurality of states are below a threshold transmit power, when more than one power allocation pattern is received indicating differing transmit powers for the respective ones of the plurality of PRBs.

6. The pico base station of claim 2, wherein the CPU is further configured to set ones of the plurality of states corresponding to ones of the plurality of PRBs having a non-zero transmit power above a threshold of the at least one power allocation pattern to the high interference state, if only one power allocation pattern is received.

7. The pico base station of claim 1, wherein the CPU is further configured to select ones of the at least one macro base station to receive a traffic load report of at least one victim UE associated with the pico base station, based on a RSRP of the at least one victim UE.

8. The pico base station of claim 7, wherein the CPU is further configured to transmit the traffic load report to the select ones of the at least one macro base station, if a number of the at least one victim UE exceeds a threshold.

9. A system, comprising:

at least one pico base station configured to;

generate interference distribution information for user equipment (UE) scheduling based on at least one power allocation pattern of a plurality of physical resource blocks (PRBs) associated with at least one macro base station; and

schedule at least one UE associated with the at least one pico base station based on the interference distribution information;

and, the at least one macro base station configured to;

determine the at least one power allocation pattern for the plurality of PRBs managed by the at least one macro base station, based on a traffic load of at least one victim UE; and

transmit the power allocation pattern to the at least one pico base station associated with the at least one victim UE.

10. The system of claim 9, wherein the interference distribution information comprises a plurality of states indicative of one of a high interference state and a low interference state for each of the plurality of PRBs.

11. The system of claim 10, wherein the at least one pico base station is further configured to determine a number of cell-edge UEs from the at least one UE associated with the at least one pico base station for scheduling at a subframe having the low interference state, the number of the cell-edge UEs determined based on a reference signal received power (RSRP) from the at least one pico base station.

12. The system of claim 10, wherein the at least one pico base station is further configured to set ones of the plurality of states corresponding to ones of the plurality of PRBs to the high interference state if more than one power allocation pattern is received indicating differing transmit powers for the respective ones of the plurality of PRBs and the transmit power of one of the plurality of PRBs from any received power allocation pattern corresponding to the ones of plurality of states is above a threshold.

13. The system of claim 9, wherein the at least one macro base station is further configured to adjust transmit power of each of the plurality of PRBs to one of a first transmit power, a second transmit power that is less than the first transmit power, and no transmit power.

14. The system of claim 13, wherein the at least one macro base station is further configured to receive a configuration of the second transmit power as a percentage of the first transmit power.

15. The system of claim 13, wherein the at least one power allocation pattern comprises:

a first map comprising information representative of ones of the plurality of PRBs configured with the first transmit power for a corresponding subframe; and

a second map comprising information representative of ones of the plurality of PRBs configured with the second transmit power for a corresponding frequency band.