METHOD FOR CONTROLLING TRANSMISSION POWER IN CELLULAR SYSTEM

• US 20110143806A1
• Filed: 08/25/2010
• Published: 06/16/2011
• Est. Priority Date: 12/15/2009
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: SONG, Young Seog, Kwon, Dong Seung
• Granted Patent: US 8,606,312 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 16/08 Load shedding arrangements
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/386 centralized, e.g. when the radio network controller or equivalent takes part in the power control

Abstract

A method for controlling transmission power of a base station in a cellular system includes: receiving a reference signal from at least one neighbor base station that is located around the base station; estimating a radio environment between the base station and the neighbor base station by using the receiving power of the reference signal; and controlling cell coverage of the base station by determining the transmission power based on the radio environment.

Claims

1. A method for controlling transmission power of a base station in a cellular system, comprising:

receiving a reference signal from at least one neighbor base station that is located around the base station;

estimating a radio environment between the base station and the neighbor base station by using the receiving power of the reference signal; and

controlling a cell coverage of the base station by determining the transmission power based on the radio environment.

2. The method of claim 1, wherein

the radio environment includes a distance between the base station and the neighbor base station.

3. The method of claim 1, wherein

the reference signal is allocated to different radio resources for each base station.

4. The method of claim 3, wherein

the radio resources are at least one of a time resource, a frequency resource, and a code resource.

5. The method of claim 1, wherein

the reference signal includes an indicator to identify the base station.

6. The method of claim 1, wherein

the reference signal transmitted by the base station and the reference signal transmitted by the neighbor base station are transmitted at power having the same magnitude.

7. The method of claim 1, wherein

the estimating the radio environment comprises:

obtaining the path loss between the base station and the neighbor base station from the receiving power of the reference signal; and

estimating a distance between the base station and the neighbor base station from the path loss, and

the controlling the cell coverage comprises;

controlling the cell coverage based on the estimated distance; and

determining the transmission power to obtain receiving power having a desired magnitude at a boundary of the controlled cell coverage.

8. The method of claim 7, further comprising

obtaining a correlation value between the reference signal transmitted by the base station and the reference signal received from the neighbor base station and comparing the correlation value with a predetermined threshold value to determine whether there is a neighbor base station.

9. A method for controlling transmission power of a plurality of base station in a control station of a cellular system, comprising:

receiving a position of each base station from the plurality of base stations;

determining transmission power of each base station in consideration of the position of each base station in order to control each cell coverage; and

informing each base station of the control information on the transmission power.

10. The method of claim 9, wherein

the control station determines the transmission power by further considering a channel state.

11. The method of claim 10, wherein

the channel state corresponds to at least one of a signal to noise ratio (SNR), a signal to interference and noise ratio (SINR), and a channel quality indicator (CQI).

12. A base station, comprising:

a reference signal receiver that receives a reference signal from a neighbor base station;

a transmission power calculator that calculates transmission power by using the received reference signal; and

a power controller that transmits the reference signal to the neighbor base station at predetermined power and transmits a signal to an user equipment in a cell based on the transmission power calculated in the transmission power calculator.

13. The base station of claim 12, wherein

the reference signal receiver directly receives the reference signal or receives the reference signal through a receiving apparatus connected to the base station.

14. The base station of claim 12, wherein

the transmission power calculator calculates the transmission power by estimating a distance between the base station and the neighbor base station by using the reference signal, controlling the cell coverage from the estimated distance, and obtaining the receiving power having a desired magnitude at a boundary of the cell coverage.