Method and system for frequency reuse in wireless relay scenario

• US 9,491,767 B2
• Filed: 12/12/2011
• Issued: 11/08/2016
• Est. Priority Date: 07/25/2011
• Status: Active Grant

• Current Assignee: ZTE Corporation
• Original Assignee: ZTE Corporation
• Inventors: Wang, Yanlong, Chang, Yongyu, Gao, Jie, Zhu, Yun
• Primary Examiner(s): Liu, Jung-Jen
• Application Number:
  US14/234,730
• Publication Number:
  US 20140192706A1
• Time in Patent Office: 1,793 Days
• US Class Current: 1/1
• CPC Class Codes: H04W 16/04 Traffic adaptive resource partitioning
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

The disclosure provides a method for frequency reuse in a wireless relay scenario, wherein a center frequency spectrum, an edge frequency spectrum and a random access frequency spectrum are pre-allocated to a cell according to a scenario parameter in the cell; load conditions of all mobile stations (MSs) covered by each relay station (RS) in the cell is calculated and reported to a base station (BS); the BS allocates the random access frequency spectrum to an RS according to load conditions of all RSs and schedules MSs. The disclosure also provides a system for frequency reuse in a wireless relay scenario. With the method and system above, the frequency spectrum planning is configurable, the random access frequency spectrum is introduced, and both the load balancing and user fairness are taken into consideration, which improves the throughput at the edge of the cell, especially can increase the throughput for the users whose throughput ranks poorly.

Claims

1. A method for frequency reuse in a wireless relay scenario, comprising:

a base station, BS, pre-allocating a center frequency spectrum, an edge frequency spectrum and a random access frequency spectrum to a cell according to a scenario parameter in the cell;

a relay station, RS, calculating load conditions of all mobile stations, MSs, covered by each RS in the cell and reporting the load conditions to the BS;

the BS allocating the random access frequency spectrum to an RS according to load conditions of all RSs and scheduling an MS;

wherein the pre-allocated center frequency spectrum is the frequency spectrum that is used for data transmission of a direct link from the BS to the MS within the coverage of the cell, the edge frequency spectrum is the frequency spectrum that is used for data transmission of a reverse link from the BS to the RS and a access link from the RS to the MS at the cell edge, the rest of the frequency spectrums are the random access frequency spectrum;

wherein the scenario parameter in the cell comprises;

the number of the RSs in the cell, positions of the RSs in the cell, a frame type of the cell, and statistic characteristics of users of the cell.

2. The method as claimed in claim 1, wherein before calculating the load conditions of all the MSs covered by each RS in the cell, the method further comprises:

distinguishing an MS accessing through an RS from all MSs in the cell.

3. The method as claimed in claim 1, wherein after pre-allocating the center frequency spectrum, the edge frequency spectrum and the random access frequency spectrum, the method further comprises:

judging whether a preset time arrives, if the preset time arrives, calculating the load conditions of all the MSs covered by each RS in the cell, or distinguishing an MS accessing through an RS from all MSs in the cell;

otherwise, maintaining wideband resources of the RSs.

4. The method as claimed in claim 1, wherein the BS allocating the random access frequency spectrum to each RS according to the load conditions of all the RSs comprises:

the BS sorting all the RSs according to the load conditions;

calculating a relative load factor of each RS according to a load factor of an RS with a lightest load;

according to the relative load factor;

calculating a probability that the random access frequency spectrum is allocated to each RS, and allocating the random access frequency spectrum to an RS with a highest probability.

5. The method as claimed in claim 1, wherein scheduling the MS is embodied as:

scheduling the MS by means of a proportional fairness scheduling algorithm.

10. The method as claimed in claim 2, wherein after pre-allocating the center frequency spectrum, the edge frequency spectrum and the random access frequency spectrum, the method further comprises:

judging whether a preset time arrives, if the preset time arrives, calculating the load conditions of all the MSs covered by each RS in the cell, or distinguishing an MS accessing through an RS from all MSs in the cell;

otherwise, maintaining wideband resources of the RSs.

11. The method as claimed in claim 2, wherein the BS allocating the random access frequency spectrum to each RS according to the load conditions of all the RSs comprises:

the BS sorting all the RSs according to the load conditions;

calculating a relative load factor of each RS according to a load factor of an RS with a lightest load;

according to the relative load factor;

calculating a probability that the random access frequency spectrum is allocated to each RS, and allocating the random access frequency spectrum to an RS with a highest probability.

12. The method as claimed in claim 2, wherein scheduling the MS is embodied as:

scheduling the MS by means of a proportional fairness scheduling algorithm.

6. A system for frequency reuse in a wireless relay scenario, comprising a base station , BS, and one or more relay station , RSs, wherein

the BS is configured to pre-allocate a center frequency spectrum, an edge frequency spectrum and a random access frequency spectrum to a cell according to a scenario parameter in the cell, allocate the random access frequency spectrum to an RS according to load conditions of all RSs and schedule a mobile station , MS;

the RS is configured to calculate load conditions of all MSs covered by each RS in the cell and report the load conditions to the BS;

wherein the pre-allocated center frequency spectrum is the frequency spectrum that is used for data transmission of a direct link from the BS to the MS within the coverage of the cell, the edge frequency spectrum is the frequency spectrum that is used for data transmission of a reverse link from the BS to the RS and a access link from the RS to the MS at the cell edge, the rest of the frequency spectrums are the random access frequency spectrum;

wherein the scenario parameter in the cell comprises;

the number of the RSs in the cell, positions of the RSs in the cell, a frame type of the cell, and statistic characteristics of users of the cell.

7. The system as claimed in claim 6, wherein the BS is further configured to distinguish an MS accessing through an RS from all MSs in the cell.

8. The system as claimed in claim 6, wherein the BS is further configured to judge whether a preset time arrives, if the preset time arrives, calculate the load conditions of all the MSs covered by each RS in the cell, or distinguish an MS accessing through an RS from all MSs in the cell;

otherwise, maintain wideband resources of the RSs.

9. The system as claimed in claim 6, wherein the BS allocating the random access frequency spectrum to each RS according to the load conditions of all the RSs comprises:

the BS sorting all the RSs according to the load conditions;

calculating a relative load factor of each RS according to a load factor of an RS with a lightest load;

according to the relative load factor, calculating a probability that the random access frequency spectrum is allocated to each RS, and allocating the random access frequency spectrum to an RS with a highest probability.

13. The system as claimed in claim 7, wherein the BS is further configured to judge whether a preset time arrives, if the preset time arrives, calculate the load conditions of all the MSs covered by each RS in the cell, or distinguish an MS accessing through an RS from all MSs in the cell;

otherwise, maintain wideband resources of the RSs.

14. The system as claimed in claim 7, wherein the BS allocating the random access frequency spectrum to each RS according to the load conditions of all the RSs comprises:

the BS sorting all the RSs according to the load conditions;

calculating a relative load factor of each RS according to a load factor of an RS with a lightest load;

according to the relative load factor, calculating a probability that the random access frequency spectrum is allocated to each RS, and allocating the random access frequency spectrum to an RS with a highest probability.