Allocating resources in a frequency-time space to mobile station data

• US 9,191,164 B2
• Filed: 09/26/2012
• Issued: 11/17/2015
• Est. Priority Date: 12/08/2006
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bontu, Chandra, Larijani, Parsya, Hawryluck, Mark
• Primary Examiner(s): Smarth, Gerald
• Application Number:
  US13/627,010
• Publication Number:
  US 20130028233A1
• Time in Patent Office: 1,147 Days
• Field of Search: 370/330
• US Class Current: 1/1
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0069 Allocation based on distance or geographical location allocation based on terminal or device properties in general, H04W72/51
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames

Abstract

To allocate resources in an orthogonal frequency domain multiple access (OFDMA) system, two-dimensional rectangular regions are assigned in a frequency-time space to data bursts associated with mobile stations. At least one data burst does not fit in an available space in the frequency-time space is determined. In response to the determining, the assigned two-dimensional rectangular regions are reshaped.

Claims

1. A method of allocating resources in an orthogonal frequency domain multiple access (OFDMA) system, comprising:

a wireless device assigning two-dimensional rectangular regions in a frequency-time space to data bursts associated with mobile stations using at least one predefined shaping rule;

the wireless device determining that at least one data burst does not fit in an available space in the frequency-time space; and

in response to the determining, the wireless device reshaping the assigned two-dimensional rectangular regions, wherein reshaping the assigned two-dimensional rectangular region comprises modifying the at least one predefined shaping rule to adjust a shape of at least one rectangular region specified by the at least one predefined shaping rule, wherein modifying the at least one predefined shaping rule comprises relaxing the at least one predefined shaping rule to allow more data bursts to be allocated to regions in the frequency-time space.

2. The method of claim 1, wherein assigning the two-dimensional rectangular regions in the frequency-time space is based on a criterion that specifies that the frequency-time space is to be as fully utilized as possible.

3. The method of claim 1, further comprising:

applying a fitting algorithm to further define the two-dimensional rectangular regions, where the fitting algorithm assigns differently shaped two-dimensional regions to fast-moving mobile stations and to slow-moving mobile stations.

4. The method of claim 3, wherein the fitting algorithm uses a criterion that specifies that data burst errors is to be reduced.

5. The method of claim 3, wherein the fitting algorithm increases a ratio of a width of the rectangular region to a height of the rectangular region for a mobile station that is fast moving, and increases a ratio of a height of the rectangular region to a width of the rectangular region for a mobile station that is slow moving.

6. The method of claim 5, wherein the fitting algorithm specifies that the corresponding two-dimensional rectangular region is to be as close as possible to a square for a mobile station that is neither fast moving nor slow moving.

7. The method of claim 1, further comprising:

dividing a number of slots in the two-dimensional rectangular region allocated to each mobile station by prime factors;

providing the prime factors to a fitting algorithm; and

using, by the fitting algorithm, the prime factors to further shape the two-dimensional rectangular regions.

8. The method of claim 7, further comprising using combinations of the prime factors to define a height and a width of the two-dimensional rectangular region for each mobile station.

9. The method of claim 8, wherein using the prime factors to further shape the two-dimensional rectangular region for each mobile station comprises:

using the prime factors to define a wide, flat rectangular region for a fast-moving mobile station; and

using the prime factors to define a tall, skinny rectangular region for a slow-moving mobile station.

10. The method of claim 7, further comprising:

determining whether the number of slots is exactly divisible by the prime factors;

in response to determining that the number of slots is not exactly divisible by the prime factors, adjusting the number of slots in the corresponding two-dimensional rectangular region.

11. The method of claim 1, wherein assigning the two-dimensional rectangular regions in the frequency-time space comprises assigning the two-dimensional rectangular regions for downlink data bursts.

12. A base station comprising:

a wireless transceiver, configured to communicate with mobile stations; and

processing hardware coupled to the wireless transceiver, wherein the processing hardware is configured to implement a scheduler, wherein the scheduler is configured to;

assign data bursts associated with mobile stations communicated with the base station to two-dimensional rectangular regions in a frequency-time space;

shape the two-dimensional rectangular regions based on speeds of the mobile stations;

determine that at least one data burst does not fit in an available space in the frequency-time space; and

in response to the determining, reshaping the assigned two-dimensional rectangular regions, wherein the scheduler is configured to further relax rules associated with shaping the two-dimensional rectangular regions according to the speeds of the mobile stations in reshaping the assigned two-dimensional rectangular regions to allow more data bursts to be allocated to regions in the frequency-time space.

13. The base station of claim 12, wherein the shaping of the two-dimensional rectangular regions is based on a first shaping rule for fast-moving mobile stations having speeds above a first threshold, and a second, different shaping rule for slow-moving mobile stations having speeds below a second threshold.

14. A non-transitory, computer-readable storage medium containing program instructions executable by a processor to:

assign two-dimensional rectangular regions in a frequency-time space to data bursts associated with mobile stations using at least one predefined shaping rule;

determine that at least one data burst does not fit in an available space in the frequency-time space; and

in response to the determining, reshape the assigned two-dimensional rectangular regions, wherein reshaping the assigned two-dimensional rectangular region comprises modifying the at least one predefined shaping rule to adjust a shape of at least one rectangular region specified by the at least one predefined shaping rule, wherein modifying the at least one predefined shaping rule comprises relaxing the at least one predefined shaping rule to allow more data bursts to be allocated to regions in the frequency-time space.

15. The non-transitory, computer-readable storage medium of claim 14, wherein the program instructions are further executable to:

apply a fitting algorithm to further shape the two-dimensional rectangular regions, where the fitting algorithm shapes the two-dimensional regions according to speeds of the mobile stations.

16. The non-transitory, computer-readable storage medium of claim 15, wherein the fitting algorithm increases a ratio of a width of the rectangular region to a height of the rectangular region for a mobile station that is fast moving, and increases a ratio of a height of the rectangular region to a width of the rectangular region for a mobile station that is slow moving.

17. The non-transitory, computer-readable storage medium of claim 16, wherein the fitting algorithm specifies that the corresponding two-dimensional rectangular region is to be as close as possible to a square for a mobile station that is neither fast moving nor slow moving.

18. The non-transitory, computer-readable storage medium of claim 14, wherein the program instructions are further executable to:

divide a number of slots in the two-dimensional rectangular region allocated to each mobile station by prime factors;

provide the prime factors to a fitting algorithm; and

use, by the fitting algorithm, the prime factors to further shape the two-dimensional rectangular regions.

19. The non-transitory, computer-readable storage medium of claim 14, wherein the program instructions are further executable to:

use combinations of the prime factors to define a height and a width of the two-dimensional rectangular region for each mobile station.