Method, System and Apparatus for Implementing Soft Frequency Reuse in Wireless Communication system

• US 20070242769A1
• Filed: 05/31/2007
• Published: 10/18/2007
• Est. Priority Date: 12/01/2004
• Status: Abandoned Application

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Yang, Xuezhi
• Application Number:
  US11/756,473
• Publication Number:
  US 20070242769A1
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level

Abstract

The embodiments of the present invention disclose a method, system and apparatus for implementing soft frequency reuse in a wireless communication system, the method includes: selecting for a cell or sector at least one carrier as a primary carrier and at least one carrier as a secondary carrier, the primary carrier and the secondary carrier are different; setting a first transmit power threshold for the primary carrier; setting a second transmit power threshold for the secondary carrier; the primary carrier selected for the cell or sector and a primary carrier selected for another cell or sector adjacent to the cell or sector are non-overlapped, and the first transmit power threshold is higher than the second transmit power threshold. The method, system and apparatus may reduce inter-cell interference and fully utilize frequency resources.

Claims

1. A method for implementing soft frequency reuse in a wireless communication system, comprising:

selecting for a cell or sector at least one carrier as a primary carrier and at least one carrier as a secondary carrier, the primary carrier and the secondary carrier are different;

setting a first transmit power threshold for the primary carrier;

setting a second transmit power threshold for the secondary carrier;

the primary carrier selected for the cell or sector and a primary carrier selected for another cell or sector adjacent to the cell or sector are non-overlapped, and the first transmit power threshold is higher than the second transmit power threshold.

2. The method of claim 1, wherein the selecting at least one carrier as a primary carrier and at least one carrier as a secondary carrier comprises:

dividing carriers into at least one first group and at least one second group;

selecting a carrier in the at least one first group as the primary carrier; and

selecting a carrier in the at least one second group as the secondary carrier.

3. The method of claim 2, wherein the dividing carriers into at least one first group and at least one second group is implemented by one of the following ways:

dividing the carriers into the at least one first group and at least one second group dynamically;

dividing the carriers into the at least one first group and at least one second group in a static way.

4. The method of claim 2, wherein the carriers are divided into three groups, one of the three groups is selected as the primary carrier, and the other two groups are selected as the secondary carrier.

5. The method of claim 1, wherein the transmit power of the primary carrier is not higher than the first transmit power threshold set for the primary carrier;

and

the transmit power of the secondary carrier is not higher than the second transmit power threshold set for the secondary carrier.

6. The method of claim 1, further comprising:

using the primary carrier in the cell or sector; and

using the secondary carrier in an inner zone of the cell or sector;

wherein the transmit power of one carrier used in the cell or sector is not higher than the first transmit power threshold when the primary carrier is used in the cell or sector, and the transmit power of one carrier used in the inner zone of the cell or sector is not higher than the second transmit power threshold when the secondary carrier in the inner zone of the cell or sector.

7. The method of claim 6, wherein the inner zone of the cell or sector is an area of which radius is 20%, 30% or 50% of the radius of the cell or sector taking a base station managing the cell or sector as the center.

8. The method of claim 1, wherein the wireless communication system is a multi-carrier wireless communication system, and the primary carrier and the secondary cattier are sub-carriers in the multi-carrier wireless communication system.

9. The method of claim 8, further comprising:

using, by a full coverage type channel in the cell or sector, the primary sub-carrier.

10. The method of claim 8, further comprising:

bearing, by the primary sub-carrier in the cell or sector, signaling.

11. The method of claim 8, further comprising:

using, by a service channel in the cell or sector, the primary sub-carrier when a terminal is located in an area beyond a predetermining distance to the center of the cell or sector.

12. The method of claim 1, further comprising:

adjusting the ratio of the second transmit power threshold set for the secondary carrier to the first transmit power threshold set for the primary carrier dynamically.

13. The method of claim 12, wherein the adjusting the ratio dynamically comprises:

reducing the ratio of the second transmit power threshold to the first transmit power threshold if a proportion of traffic in an area beyond a predetermining distance to the center of the cell or sector to a total traffic of the cell or sector increases; and

increasing the ratio of the second transmit power threshold to the first transmit power threshold if the proportion of the traffic in the area beyond the predetermining distance to the center of the cell or sector to the total traffic of the cell or sector decreases.

14. An apparatus for implementing soft frequency reuse in a wireless communication system, comprising:

a serial-to-parallel converter, configured to converting a data entered in serial into multiple parallel data sub-streams and export the data sub-streams;

an inverse Fourier transformer, configured to perform inverse Fourier transform for the data sub-streams, and map the data sub-streams onto multiple carriers, respectively;

a parallel-to-serial converter, configured to convert the multiple carriers into one data stream and export the data stream;

an adjuster, configured to multiply the parallel data sub-streams exported by the serial-to-parallel converter by a power coefficient;

the power coefficient is used for adjusting transmit power of each carrier is not higher than a transmit power threshold; and

a control device, configured to control the power coefficient is not higher than a threshold of the power coefficient.

15. The apparatus of claim 14, wherein at least one carrier is selected as a primary carrier and at least one carrier is selected as a secondary carrier;

the control device adjusts the ratio of a transmit power threshold set for the secondary carrier to a transmit power threshold set for the primary carrier dynamically.

16. The apparatus of claim 15, wherein the control device comprises:

a first unit, configured to reduce the ratio of the transmit power threshold set for the secondary carrier to the transmit power threshold set for the primary carrier if a proportion of traffic in an area beyond a predetermining distance to the center of a cell or sector to a total traffic of the cell or sector increases; and

a second unit, configured to increase the ratio of the transmit power threshold set for the secondary carrier to the transmit power threshold set for the primary carrier if the proportion of the traffic in the area beyond the predetermining distance to the center of the cell or sector to the total traffic of the cell or sector decreases.

17. A system for implementing soft frequency reuse in a wireless communication system, comprising:

a first unit, configured to select for a cell or sector at least one carrier as a primary carrier and at least one carrier as a secondary carrier, the primary carrier selected for the cell or sector and a primary carrier selected for another cell or sector adjacent to the cell or sector are non-overlapped; and

a second unit, configured to set a first transmit power threshold for the primary carrier and a second transmit power threshold for the secondary carrier, the first transmit power threshold is higher than the second transmit power threshold.

18. The system of claim 17, further comprising:

a first terminal in an area beyond a predetermining distance to the center of the cell or sector, configured to adapt the primary carrier;

a second terminal in an inner zone of the cell or sector configured to adapt the secondary carrier;

the transmit power of the first terminal is not higher than the first transmit power threshold and the transmit power of the second terminal is not higher than the second transmit power threshold.