DOWNLINK POWER CONTROL METHOD AND APPARATUS OF OFDM SYSTEM

• US 20130157709A1
• Filed: 12/20/2012
• Published: 06/20/2013
• Est. Priority Date: 12/20/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: JI, Hyoungju, KIM, Younsun, CHO, Joonyoung, CHOI, Seunghoon, KIM, Kiil, LEE, Hyojin
• Granted Patent: US 9,072,054 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations

Abstract

A downlink power control method and apparatus for improving downlink power efficiency gain in an Orthogonal Frequency Division Multiplexing (OFDM) system is provided. The downlink power control method includes transmitting a downlink data channel at a normal subframe according to first downlink power information for the normal subframe, and transmitting the downlink data channel at an Almost Blank Subframe (ABS) according to second downlink power information for the ABS, wherein the first downlink power information for the normal subframe and the second downlink power information for the ABS differ from each other. The downlink power control method and apparatus is capable of regulating inter-cell interference variation between contiguous symbols at a predetermined level in a subframe at a terminal of a neighbor cell and making it possible to schedule the UE receiving the low power data channel using the power ratio of the feedbacks from the UE.

Claims

1. A downlink power control method of a base station, the method comprising:

transmitting a downlink data channel at a normal subframe according to first downlink power information for the normal subframe; and

transmitting the downlink data channel at an Almost Blank Subframe (ABS) according to second downlink power information for the ABS,

wherein the first downlink power information for the normal subframe and the second downlink power information for the ABS differ from each other.

2. The downlink power control method of claim 1, wherein the transmitting of the downlink data channel at the normal subframe comprises allocating different transmit powers for symbols carrying Common Reference Signal (CRS) and symbols carrying no CRS in the normal subframe according to a predetermined ratio, and

wherein the transmitting of the downlink data channel at the ABS comprises allocating a same transmit power for symbols carrying CRS and symbols carrying no CRS in the ABS.

3. The downlink power control method of claim 1, wherein the transmitting of the downlink data channel at the ABS comprises skipping a mapping of the downlink data channel to symbols carrying Common Reference Signal (CRS) in the ABS.

4. The downlink power control method of claim 1, further comprising:

configuring the first downlink power information for the normal subframe and the second downlink power information for the ABS; and

transmitting the first downlink power information for the normal subframe and the second downlink power information for the ABS to a terminal.

5. A base station for controlling downlink power, the base station comprising:

a transmitter for transmitting a downlink data channel at a normal subframe according to first downlink power information for the normal subframe and for transmitting a downlink data channel at an almost Blank Subframe (ABS) according to second downlink power information for the ABS,

wherein the first downlink power information for the normal subframe and the second downlink power information for the ABS differ from each other.

7. The base station of claim 5, further comprising:

a controller for controlling the transmitter to skip a mapping of the downlink data channel to symbols carrying Common Reference Signal (CRS) in the ABS.

8. The base station of claim 5, further comprising:

a controller for configuring the first downlink power information for the normal subframe and the second downlink power information for the ABS,

wherein the transmitter transmits the first downlink power information for the normal subframe and the second downlink power information for the ABS to a terminal.

6. The base station of claim 6, wherein the transmitter allocates different transmit powers for symbols carrying Common Reference Signal (CRS) and symbols carrying no CRS in the normal subframe according to a predetermined ratio and a same transmit power for symbols carrying CRS and symbols carrying no CRS in the ABS.

9. A downlink reception method of a terminal, the method comprising:

receiving a downlink data channel at a normal subframe according to first downlink power information for the normal subframe; and

receiving the downlink data channel at an Almost Blank Subframe (ABS) according to second downlink power information for the ABS,

wherein the first downlink power information for the normal subframe and the second downlink power information for the ABS differ from each other.

10. The downlink reception method of claim 9, wherein the receiving of the downlink data channel at the normal subframe comprises applying different transmit powers to receive symbols carrying Common Reference Signal (CRS) and symbols carrying no CRS in the normal subframe according to a predetermined ratio, and

wherein the receiving of the downlink data channel at the ABS comprises applying a same transmit power to receive symbols carrying CRS and symbols carrying no CRS in the ABS.

11. The downlink reception method of claim 9, further comprising:

receiving the first downlink power information for the normal subframe and the second downlink power information for the ABS; and

receiving the downlink data channel in the normal subframe and the ABS according to the first downlink power information and the second downlink power information.

12. A terminal for receiving downlink data channel, the terminal comprising:

a receiver for receiving a downlink data channel at a normal subframe according to first downlink power information for a normal subframe and for receiving a downlink data channel at an Almost Blank Subframe (ABS) according to second downlink power information for ABS,

wherein the first downlink power information for the normal subframe and the second downlink power information for the ABS differ from each other.

13. The terminal of claim 12, wherein the receiver applies different transmit powers to receive symbols carrying Common Reference Signal (CRS) and symbols carrying no CRS in the normal subframe according to a predetermined ratio and applies a same transmit power to receive symbols carrying CRS and symbols carrying no CRS in the ABS.

14. The terminal of claim 12, wherein the receiver receives the first downlink power information for the normal subframe and the second downlink power information for the ABS and receives the downlink data channel in the normal subframe and ABS according to the first downlink power information and the second downlink power information.