Method and apparatus for channel sensitive scheduling in a communication system

• US 7,551,637 B2
• Filed: 01/20/2005
• Issued: 06/23/2009
• Est. Priority Date: 01/23/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Malladi, Durga Prasad, Willenegger, Serge D., Damnjanovic, Jelena
• Primary Examiner(s): PHAN, MAN U
• Application Number:
  US11/040,871
• Publication Number:
  US 20050201281A1
• Time in Patent Office: 1,615 Days
• Field of Search: 370230-235, 370335-342, 370412-474, 370389-395, 455435-450, 709200-211
• US Class Current: 370/412
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/626 channel conditions
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 72/566 of the information or information source or recipient
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

Method and apparatus for a channel sensitive scheduler for scheduling transmissions in a communication system. The scheduler is defined by a priority function of the channel condition as determined by amount of transmission power needed by a mobile station. In one embodiment the channel condition is determined based on the transmission pilot power of each mobile station and is used to calculate a priority value for each mobile station. The mobile stations are then scheduled to transmit based on the priority value.

Claims

1. A method of scheduling transmissions in a wireless communication system, comprising:

receiving a channel condition indicator sent by a mobile station at a scheduler,

determining a priority value for the mobile station using a function;

Priority(i)=Pilot_Power_Max−

Pilot_Power(i),

where Priority(i) is the priority value for the ith mobile user, Pilot_Power_Max is the mobile station'"'"'s maximum pilot power, and Pilot_Power(i) is the mobile station'"'"'s pilot power at time of scheduling.

2. The method of claim 1 further comprising:

calculating priority values for a plurality of mobile stations as a function of the channel condition indicator; and

selecting at least one of the plurality of mobile stations for a subsequent transmission based on the priority value.

3. The method of claim 1 wherein:

the channel condition indicator is based upon the mobile station'"'"'s transmit pilot power and requested data rate.

4. The method of claim 1 wherein:

the channel condition indicator is based upon the mobile station'"'"'s transmit power as determined by power control commands.

5. A method of scheduling in a wireless communication system, comprising:

receiving a channel condition indicator sent by a mobile station at a scheduler,

determining a priority value for the mobile user using a function;

Priority(i)=a(i)*(Pilot_Power_Average(i)/Pilot Power(i))

where Priority(i) is a priority value for an i-th mobile user, Pilot_Power_Average(i) is a mobile station'"'"'s pilot power averaged over a certain period of time, Pilot_Power(i) is a mobile station'"'"'s pilot power at the moment of scheduling, and a(i) is a weighting factor.

6. The method of claim 5 wherein:

the weighting factor is based upon the mobile user'"'"'s speed.

7. The method of claim 5 wherein:

the weighing factor is computed according to a function;

a(i)=(sector_throughput/user_throughput(i))^b, where 0≦

b≦

1.

8. A computer-readable medium containing computer-executable instructions for performing a method of scheduling transmissions, the method comprising:

processing channel condition indicators received from a plurality of mobile stations;

calculating a priority value for each of a plurality of mobile stations using a function;

Priority(i)=Pilot_Power_Max−

Pilot_Power(i),

where Priority(i) is the priority value for the ith mobile station Pilot_Power_Max is the mobile station'"'"'s maximum pilot power, and Pilot_Power(i) is the mobile user'"'"'s pilot power at time of scheduling; and

determining a transmission schedule for the plurality of mobile stations as a function of the priority values.

9. A computer-readable medium containing computer-executable instructions for performing a method of scheduling transmissions, the method comprising:

processing channel condition indicators received from a plurality of mobile stations;

calculating a priority value for each of a plurality of mobile stations using a function;

Priority(i)=a(i)*(Pilot_Power_Average(i)/Pilot_Power(i))

where Priority(i) is a priority value for an i-th mobile station, Pilot_Power_Average(i) is the mobile station'"'"'s pilot power averaged over a certain period of time, Pilot_Power(i) is the mobile station'"'"'s pilot power at the moment of scheduling, and a(i) is the weighting factor; and

determining a transmission schedule for the plurality of mobile stations as a function of the priority values.

10. The computer-readable medium as in claim 9, wherein the weighting factor is computed according to a function:

a(i)=(sector_throughput/user_throughput(i))^b, where 0≦

b≦

1.

11. An apparatus, comprising:

means for receiving channel condition indicators from a plurality of mobile stations;

means for determining a priority value for each mobile station, wherein the priority value is a function of;

Priority(i)=Pilot_Power_Max−

Pilot_Power(i),

where Priority(i) is the priority value for the ith mobile station Pilot_Power_Max is the mobile station'"'"'s maximum pilot power, and Pilot_Power(i) is the mobile station'"'"'s pilot power at time of scheduling; and

means for determining a transmission schedule for the plurality of mobile stations based on the priority values.

12. An apparatus, comprising:

means for receiving channel condition indicators from a plurality of mobile stations;

means for determining a priority value for each mobile station, wherein the priority value is a function of;

Priority(i)=a(i)*(Pilot_Power_Average(i)/Pilot_Power(i))

where Priority(i) is a priority value for an i-th mobile station, Pilot_Power _Average(i) is the mobile station—

s pilot power averaged over a certain period of time Pilot_Power(i) is the mobile station'"'"'s pilot power at the moment of scheduling, and a(i) is the weighting factor; and

means for determining a transmission schedule for the plurality of mobile stations based on the priority value.

13. The apparatus of claim 12, wherein the weighting factor is a function of:

a(i)=(sector_throughput/user_throughput(i))^b, where 0≦

b≦

1.

14. An apparatus in a wireless communication system, comprising:

a processing element; and

a memory storage element coupled to the processing element, the memory storage element adapted for storing computer-readable instructions for implementing;

means for receiving a channel condition indicator from a plurality of mobile stations;

means for computing a priority value for each mobile station based on the channel condition indicator, wherein the priority value is a function of;

Priority(i)=Pilot_Power_in Max−

Pilot_Power(i),

where Priority(i) is the priority value for the ith mobile station, Pilot_Power_Max is the mobile station'"'"'s maximum pilot power, and Pilot_Power(i) is the mobile station'"'"'s pilot power at time of scheduling; and

means for scheduling the plurality of mobile stations based on the computed priority values.

15. An apparatus in a wireless communication system, comprising:

a processing element; and

a memory storage element coupled to the processing element, the memory storage element adapted for storing computer-readable instructions for implementing;

means for receiving a channel condition indicator from a plurality of mobile stations;

means for computing a priority value for each mobile station based on the channel condition indicator, wherein the priority value is a function of;

Priority(i)=a(i)*(Pilot_Power_Average(i)/Pilot_Power(i))

where Priority(i) is a priority value for an i-th mobile user, Pilot_Power_Average(i) is a mobile station'"'"'s pilot power averaged over a certain period of time, Pilot_Power(i) is a mobile station'"'"'s pilot power at the moment of scheduling, and a(i) is a weighting factor; and

means for scheduling the plurality of mobile stations based on the computed priority values.

16. The apparatus of claim 15 wherein:

the weighting factor is based upon the mobile user'"'"'s speed.

17. The apparatus of claim 15 wherein:

the weighting factor is computed according to a function;

a(i)=(sector_throughput/user_throughput(i))^b, where 0≦

b≦

1.