Integrated scheduling and power control for the uplink of an OFDMA network

• US 8,325,654 B2
• Filed: 11/14/2007
• Issued: 12/04/2012
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Hosein, Patrick
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): EBRAHIM, ANEZ C
• Application Number:
  US11/940,134
• Publication Number:
  US 20080159215A1
• Time in Patent Office: 1,847 Days
• Field of Search: 370/318, 370/329, 370/331, 370/252, 455/432, 455/436, 455/444, 455/446, 455/517, 455/522, 455/524, 455/525
• US Class Current: 370/329
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/267 taking into account the information rate

Abstract

Managing radio resources and power for OFDMA uplinks is disclosed in which a threshold transmission rate for the reverse link is used by base stations to compare against the achievable reverse link transmission rate of a particular AT within the sector serviced by the base station. When the calculated rate is higher than the threshold rate, the base station allocates maximum power to the AT. Otherwise, when the calculated rate is lower than the threshold rate, zero power is allocated to the AT.

Claims

1. A method for managing radio resources in an orthogonal frequency division multiple access (OFDMA) network, said method comprising:

periodically determining, by a base station, an optimal power allocation for an access terminal within each sector of a plurality of sectors, said periodically determining comprising;

calculating a sector transmission rate corresponding to said each sector, the calculating comprising;

detecting a power, p_i, of a transmission from said access terminal;

computing a channel gain, g_ii, within said each sector;

detecting a total interference, X_i, experienced by said each sector;

detecting a background noise, N_i, experienced by said each sector; and

calculating said sector transmission rate, r_i, using a formula;

2. The method of claim 1 wherein said threshold transmission rate is predetermined by the base station in said each sector.

3. The method of claim 1 further comprising:

routinely re-calculating said threshold transmission value based, at least in part, on a set of test threshold values, a random sequence of cells, and a set of random sector layouts.

4. The method of claim 1 further comprising:

scheduling said access terminal for reverse link transmission;

assigning said access terminal to a tile of said each sector when said power allocation of said access terminal is set to maximum power; and

withholding said access terminal from assignment to said tile when said power allocation of said access terminal is set to zero power.

5. The method of claim 1 further comprising changing, by the base station, said optimal power allocation for said access terminal to

zero power when said calculated sector transmission rate is less than or equal to said threshold transmission rate.

6. A method for managing radio resources in a sector of an orthogonal frequency division multiple access (OFDMA) network, said method comprising:

calculating, by a base station, a reverse link transmission rate for an access terminal in said sector, the calculating comprising;

detecting a power, p_i, of a transmission from said access terminal;

computing a channel gain, g_ii, within said sector;

detecting a total interference, X_i, experienced by said sector;

detecting a background noise, N_i, experienced by said sector; and

calculating said reverse link transmission rate, r_i, using the a formula;

7. The method of claim 6 further comprising:

scheduling said access terminal for reverse link transmission;

assigning said access terminal to a tile of said sector when said power allocation of said access terminal is set to maximum power; and

withholding said access terminal from assignment to said tile when said power allocation of said access terminal is set to zero power.

8. The method of claim 6, further comprising changing, by the base station, said optimal power allocation for said access terminal to zero power when said calculated reverse link transmission rate is less than or equal to said threshold transmission rate.

9. The method of claim 6 wherein said threshold transmission rate is predetermined by the base station.

10. A base station for an orthogonal frequency division multiple access (OFDMA) network, said base station comprising:

a processor;

memory, accessible by said processor;

a power control module stored in said memory and executable by said processor, said power control module comprising;

a transmission rate calculator configured to calculate a reverse link transmission rate for an access terminal in a sector served by said base station, the transmission rate calculator further configured to;

receive a power, p_i, of a transmission detected by said base station from said access terminal;

receive a channel gain, g_ii, computed by said base station within said sector;

receive a total interference, X_i, detected by said base station in said sector as detected by said base station;

receiving a background noise, N_i, detected by said base station in said sector; and

calculate said reverse link transmission rate, r_i, using a formula;

11. The base station of claim 10 further comprising:

a scheduler configured to schedule said access terminal for reverse link transmission; and

a radio resource manager configured to assign said access terminal to a tile of said sector when said power allocation of said access terminal is set to maximum power and withhold said access terminal from assignment to said tile when said power allocation of said access terminal is set to zero power.

12. The base station of claim 10 wherein said power allocation component is configured to allocate to said access terminal:

maximum power;

or

zero power.

13. The base station of claim 10, wherein said power allocation component is configured to allocate to said access terminal:

maximum power when said calculated reverse link transmission rate is greater than said threshold transmission rate.

14. The base station of claim 13, wherein said power allocation component is configured to allocate to said access terminal:

zero power when said calculated reverse link transmission rate is less than or equal to said threshold transmission rate.

15. The base station of claim 10 wherein said threshold transmission rate is predetermined by the base station.

16. A computer program product having a non-transitory computer readable medium with computer program logic recorded thereon, said computer program product comprising:

code for calculating a reverse link transmission rate for an access terminal in a sector of an orthogonal frequency division multiple access (OFDMA) network, the code for calculating further comprising;

code for detecting a power, p_i, of a transmission from said access terminal;

code for computing a channel gain, g_ii, within said sector;

code for detecting a total interference, X_i, experienced by said sector;

code for detecting a background noise, N_i, experienced by said sector; and

code for calculating said reverse link transmission rate, r_i, using a formula;

17. The computer program product of claim 16 further comprising:

code for scheduling said access terminal for reverse link transmission;

code for assigning said access terminal to a tile of said sector when said power allocation of said access terminal is set to maximum power; and

code for withholding said access terminal from assignment to said tile when said power allocation of said access terminal is set to zero power.

18. The computer program product of claim 16, further comprising code for setting said optimal power allocation for said access terminal to zero power when said calculated reverse link transmission rate is less than or equal to said threshold transmission rate.

19. The computer program product of claim 16, further comprising code for predetermining said threshold transmission rate.