TRANSMISSION POWER CONTROL METHOD OF BASE STATION IN OFDMA-BASED WIRELESS COMMUNICATION SYSTEM

• US 20120044845A1
• Filed: 06/13/2011
• Published: 02/23/2012
• Est. Priority Date: 08/20/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Dong Geun, PARK, Young Bae, CHOI, Young Kyu, KIM, Ki Back
• Granted Patent: US 11,457,405 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A power control method of a base station in a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA) is provided for reducing power consumption by turning off the bias of the power amplifier for the duration of a symbol carrying no user data. The method includes checking scheduling information of radio resources, detecting a symbol carrying no user data, based on the scheduling information, and turning off a bias of the power amplifier for a symbol duration of the symbol carrying no user data. The transmission power control method is capable of reducing power consumption of the base station by turning off the bias of the power amplifier of the base station for the symbol duration in which no user data is transmitted.

Claims

1. A method for controlling a power amplifier of a base station in a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA), the method comprising:

checking scheduling information of radio resources;

detecting a symbol carrying no user data, based on the scheduling information; and

turning off a bias of the power amplifier for a symbol duration of the symbol carrying no user data.

2. The method of claim 1, further comprising assigning, before checking the scheduling information, the radio resources in a symbol first across an entire frequency bandwidth completely and then in a next symbol.

3. The method of claim 1, wherein the detecting of the symbol carrying no user data comprises:

acquiring, at a symbol location indicator of a controller, information on the symbol carrying no user data; and

locating, at a symbol location detector of a Radio Frequency (RF) unit, a position of the symbol carrying no user data based on the symbol information.

4. The method of claim 3, wherein the detecting of the symbol carrying no user data further comprises calculating, at the symbol location indicator, a length of a symbol carrying user data.

5. The method of claim 4, wherein the turning off of the bias comprises:

receiving information of the symbol length; and

turning on the bias for a symbol duration of the symbol carrying user data and turning off the bias for the symbol duration of the symbol carrying no user data by referencing the information of the symbol length.

6. The method of claim 1, wherein the detecting of the symbol carrying no user data comprises acquiring, at a symbol power detector of a Radio Frequency (RF) unit, information on the symbol carrying no user data, based on power allocated to individual symbols in a frame.

7. The method of claim 6, wherein the detecting of the symbol carrying no user data further comprises locating, at a symbol location detector, a position of the symbol carrying no user data, based on the symbol information.

8. The method of claim 7, wherein the detecting of the symbol carrying no user data further comprises calculating, at the symbol location detector, a length of a symbol carrying user data.

9. The method of claim 8, wherein the turning off of the bias comprises:

receiving information of the symbol length; and

turning on the bias for a symbol duration of the symbol carrying user data and turning off the bias for the symbol duration of the symbol carrying no user data by referencing the information of the symbol length.

10. A base station for a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA), the base station comprising:

a controller for acquiring information of a symbol carrying no user data by referencing scheduling information of radio resources; and

a Radio Frequency (RF) unit for turning off a bias applied to a power amplifier for a symbol duration of the symbol carrying no user data by referencing the symbol information provided by the controller.

11. The base station of claim 10, wherein the controller comprises:

a scheduler for assigning radio resources;

a symbol location indicator for acquiring information of the symbol carrying no user data by referencing the scheduling information provided by the scheduler, and

a modem for receiving the symbol information and for outputting the symbol information to the RF unit.

12. The base station of claim 10, wherein the RF unit comprises:

a symbol location detector for locating a position of the symbol carrying no user data by referencing the symbol information provided by the controller and for calculating a length of a symbol carrying user data; and

a bias controller for turning on the bias for a symbol duration of the symbol carrying user data and for turning off the bias for the symbol duration of the symbol carrying no user data according to the length of the symbol carrying user data.

13. The base station of claim 11, wherein the scheduler assigns the radio resource first in a symbol across an entire frequency bandwidth completely and then in a next symbol.

14. The base station of claim 13, wherein the modem comprises a first interface unit for outputting the symbol information, and the modem for generating downlink subframe information including the symbol information and for transmitting the downlink subframe information to the first interface unit.

15. The base station of claim 14, wherein the downlink subframe information comprises a control information region indicating a start position of a downlink subframe and a data sample region, the control information region carrying the symbol information.

16. The base station of claim 15, wherein the controller further comprises a Digital Unit-RF unit (DU-RU) connection unit for transferring the symbol information to the RF unit, the DU-RU connection unit comprising:

a second interface unit for receiving the downlink subframe information from the first interface unit;

a conversion unit for analyzing the downlink subframe information received from the second interface unit to extract symbol information and data sample and for converting the extracted symbol information and data sample to basic frame information; and

a third interface unit for outputting the basic frame information received from the conversion unit.

17. The base station of claim 16, wherein the RF unit further comprises a fourth interface unit for receiving the basic frame information provided by the third interface unit, for extracting the symbol information from the basic frame information, and for outputting the symbol information to the symbol location indicator.

18. A base station for a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA), the base station comprising:

a controller including a scheduler for assigning radio resources; and

a Radio Frequency (RF) unit for acquiring information on a symbol carrying no user data based on transmission powers of individual symbols within a frame and for turning off a bias applied to a power amplifier for a symbol duration of the symbol carrying no user data.

19. The base station of claim 18, wherein the RF unit comprises:

a symbol power detector for acquiring information the symbol carrying no user data based on the power of the individual symbols within a frame;

a symbol location detector for locating the symbols carrying no user data based on the symbol information provided by the symbol power detector and for calculating a length of a symbol carrying user data; and

a bias controller for turning on the bias for a symbol duration of the symbol carrying user data and for turning off the bias for the symbol duration of the symbol carrying no user data according to the length of the symbol carrying user data.

20. The base station of claim 19, wherein the scheduler assigns the radio resource first in a symbol across an entire frequency bandwidth completely and then in a next symbol.