Method and apparatus for adaptive carrier allocation and power control in multi-carrier communication systems

• US 6,751,444 B1
• Filed: 07/02/2001
• Issued: 06/15/2004
• Est. Priority Date: 07/02/2001
• Status: Expired due to Fees

• Current Assignee: Adaptix, Inc. (Acacia Research Corporation)
• Original Assignee: Broadstorm Telecommunications Inc.
• Inventors: Meiyappan, Palaniappan
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): Nguyen, David
• Application Number:
  US09/898,163
• Time in Patent Office: 1,079 Days
• Field of Search: 455/450, 455/69, 455/63.1, 455/408, 455/407, 455/440, 455/441, 455/463, 375/225, 370/335, 340/7.4
• US Class Current: 455/69
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

An apparatus and process for allocating carriers in a multi-carrier system is described. In one embodiment, the process comprises determining a location of a subscriber with respect to a base station, selecting carriers from a band of carriers to allocate to the subscriber according to the location of the subscriber with respect to the base station, and allocating selected carriers to the subscriber.

Claims

1. A process for allocating carriers in a multicarrier system, the process comprising:

determining a location of a subscriber with respect to a base station;

selecting carriers from a band of multi-carriers to allocate to the subscriber according to the location of the subscriber with respect to the base station;

allocating selected carriers to the subscriber, and

indicating to the subscriber whether or not to adjust transmit power to above its normal transmit power range based, at least in part, on the selected carriers allocated to the subscriber;

wherein the closer the subscriber is to the base station the farther away the selected carriers are from the center of the band to reduce effects of inter modulation distortion (IMD) products and spectral re-growth caused by the subscriber on an adjacent channel.

2. The process defined in claim 1 wherein selecting carriers from the band of multi-carriers comprises:

selecting carriers closer to or at the center of the band when the subscriber is far away from the base station; and

selecting carriers farther away from the center of the band when the subscriber is close to the base station.

3. The process defined in claim 1 further comprising:

receiving a request from the subscriber;

calculating a time delay and a path loss associated with the subscriber; and

determining transmit power requirements for the subscriber based on the time delay and the path loss.

4. The process defined in claim 3 wherein determining transmit power requirements is further based on signal-to-noise-plus-interference ratio.

5. The process defined in claim 1 further comprising sending a command to the subscriber to use either a normal or extended power control range based on the selected carrier allocation.

6. The process defined in claim 5 further comprising adjusting a power control setting for the subscriber at the base station.

7. The process defined by claim 6 further comprising:

assigning a spectral priority code to the subscriber based on whether the subscriber is near to or far from the base station, and wherein the selected carrier allocation occurs based on the spectral priority code.

8. The process defined in claim 7 further comprising allocating carriers at the center of the band to the subscriber when the subscriber is assigned a first predetermined spectral priority code.

9. The process defined in claim 8 further comprising allocating carriers adjacent to carriers at the center of the band to the subscriber when the subscriber is assigned a second predetermined spectral priority code that is of a lower priority than the first predetermined spectral priority code.

10. The process defined in claim 1 wherein the selected carriers are orthogonal frequency division multiple access (OFDMA) carriers.

11. The process defined in claim 1 wherein indicating to the subscriber whether or not to adjust transmit power is based on meeting an Adjacent Channel Leakage Power Ratio.

12. A process for allocating carriers in a multicarrier system, the process comprising:

determining a location of a subscriber with respect to a base station;

selecting carriers from a band of multi-carriers to allocate to the subscriber according to the location of the subscriber with respect to the base station to reduce effects of inter modulation distortion (IMD) products and spectral re-growth caused by the subscriber on an adjacent channel, wherein selecting carriers from the band of multi-carriers includes

selecting carriers closer to or at the center of the band when the subscriber is far away from the base station, and

selecting carriers farther away from the center of the band when the subscriber is close to the base station;

allocating selected carriers to the subscriber; and

indicating to the subscriber whether or not to adjust transmit power to above its normal transmit power range based, at least in part, on the selected carriers allocated to the subscriber.

13. The process defined in claim 12 wherein the selected carriers are orthogonal frequency division multiple access (OFDMA) carriers.

14. The process defined in claim 12 further comprising:

receiving a request from the subscriber;

calculating a time delay and a path loss associated with the subscriber; and

determining transmit power requirements for the subscriber based on the time delay and the path loss.

15. The process defined in claim 14 wherein determining transmit power requirements is further based on signal-to-noise-plus-interference ratio.

16. The process defined in claim 12 further comprising sending a command to the subscriber to use either a normal or extended power control range based on the selected carrier allocation.

17. The process defined in claim 16 further comprising adjusting a power control setting for the subscriber at the base station.

18. The process defined by claim 17 further comprising:

assigning a spectral priority code to the subscriber based on whether the subscriber is near to or far from the base station, and wherein the selected carrier allocation occurs based on the spectral priority code.

19. The process defined in claim 18 further comprising allocating carriers at the center of the band to the subscriber when the subscriber is assigned a first predetermined spectral priority code.

20. The process defined in claim 19 further comprising allocating carriers adjacent to carriers at the center of the band to the subscriber when the subscriber is assigned a second predetermined spectral priority code that is of a lower priority than the first predetermined spectral priority code.

21. The process defined in claim 12 wherein indicating to the subscriber whether or not to adjust transmit power is based on meeting an Adjacent Channel Leakage Power Ratio.

22. An apparatus for allocating carriers in a multicarrier system, the process comprising:

means for determining a location of a subscriber with respect to a base station;

means for selecting carriers from a band of multi-carriers to allocate to the subscriber according to the location of the subscriber with respect to the base station to reduce effects of inter modulation distortion (IMD) products and spectral re-growth caused by the subscriber on an adjacent channel, wherein the means for selecting carriers from the band of multi-carriers includes

means for selecting carriers closer to or at the center of the band when the subscriber is far away from the base station, and

means for selecting carriers farther away from the center of the band when the subscriber is close to the base station;

means for allocating selected carriers to the subscriber; and

means for indicating to the subscriber whether or not to adjust transmit power to above its normal transmit power range based, at least in part, on the selected carriers allocated to the subscriber.