Resource allocation for MIMO-OFDM communication systems

• US 8,406,200 B2
• Filed: 07/27/2009
• Issued: 03/26/2013
• Est. Priority Date: 01/08/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Walton, J. Rodney, Ketchum, John W., Wallace, Mark S., Medvedev, Irina
• Primary Examiner(s): Ho, Chuong T
• Application Number:
  US12/509,941
• Publication Number:
  US 20100020757A1
• Time in Patent Office: 1,338 Days
• Field of Search: 370/334, 370/267, 370/335, 370/336, 370/337, 370342-344, 370/347, 370/437, 370441-444, 370/230, 370/232, 370/458, 370/478, 370480-481, 370/484, 370/356, 370/208, 375/224, 375/225, 375/227, 375/259, 375/260, 375/267, 375/299, 375346-348, 455/450, 455/452.1, 455/452.2, 455/561, 455/562.1
• US Class Current: 370/334
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling

Abstract

Techniques to schedule terminals for data transmission on the downlink and/or uplink in a MIMO-OFDM system based on the spatial and/or frequency “signatures” of the terminals. A scheduler forms one or more sets of terminals for possible (downlink or uplink) data transmission for each of a number of frequency bands. One or more sub-hypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to (1) specific assignments of transmit antennas to the terminal(s) in the hypothesis (for the downlink) or (2) a specific order for processing the uplink data transmissions from the terminal(s) (for the uplink). The performance of each sub-hypothesis is then evaluated (e.g., based on one or more performance metrics). One sub-hypothesis is then selected for each frequency band based on the evaluated performance, and the one or more terminals in each selected sub-hypothesis are then scheduled for data transmission on the corresponding frequency band.

Claims

1. A method of communicating data in a wireless communication system, the method comprising:

identifying a first receiver from a plurality of receivers, the first receiver being configured to substantially achieve a first predetermined level of performance, wherein a transmitter is configured to transmit data to the first receiver over a first spatial subchannel of a communication channel using a first frequency subcarrier at a first power level that is sufficient to substantially achieve a first signal-to-noise ratio at the first receiver;

identifying a second receiver from the plurality of receivers, the second receiver being configured to substantially achieve a second predetermined level of performance, wherein the transmitter is configured to transmit data to the second receiver over a second spatial subchannel of the communication channel using a second frequency subcarrier at a second power level that is sufficient to substantially achieve a second signal-to-noise ratio at the second receiver, wherein a sum of the first power level and the second power level is less than a predetermined maximum power level, and wherein the first spatial subchannel is spatially compatible with the second spatial subchannel; and

scheduling the transmitter to communicate with the first receiver over the first spatial subchannel and to communicate with the second receiver over the second spatial subchannel substantially concurrently, wherein the first frequency subcarrier is the same as the second frequency subcarrier.

2. The method of claim 1, wherein the first spatial subchannel is spatially compatible with the second spatial subchannel when the first spatial subchannel achieves a first predetermined throughput level and the second spatial subchannel achieves a second predetermined throughput level during substantially concurrent transmission over the first spatial subchannel and the second spatial subchannel.

3. The method of claim 2, wherein the sum of the first predetermined throughput level and the second predetermined throughput level is maximized.

4. The method of claim 1, wherein the first spatial subchannel comprises a first propagation path between the first receiver and the transmitter, the second spatial subchannel comprises a second propagation path between the second receiver and the transmitter, and the first propagation path is different than the second propagation path.

5. The method of claim 1, wherein the first predetermined level of performance comprises a first difference between a first setpoint signal-to-noise ratio of the first receiver and a first actual signal-to-noise ratio achievable at the first receiver during communication with the transmitter, and the second predetermined level of performance comprises a second difference between a second setpoint signal-to-noise ratio of the second receiver and a second actual signal-to-noise ratio achievable at the second receiver during communication with the transmitter.

6. The method of claim 1, further comprising:

identifying a third receiver from the plurality of receivers, the third receiver being configured to substantially achieve a third predetermined level of performance, wherein the transmitter is configured to transmit data to the third receiver using a third frequency subcarrier at a third power level that is sufficient to substantially achieve a third signal-to-noise ratio at the third receiver, wherein a sum of the first power level, the second power level, and the third power level is less than the predetermined maximum power level; and

scheduling the transmitter to communicate with the third receiver using the third frequency subcarrier substantially concurrently with the communication between the transmitter and the first receiver over the first spatial subchannel, wherein the third frequency subcarrier is different than the first frequency subcarrier.

7. The method of claim 1, wherein the first level of performance is substantially equal to the second level of performance.

8. The method of claim 1, further comprising selecting the plurality of receivers from a set of receivers, the set of receivers comprising the plurality of receivers and one or more additional receivers, wherein each of the plurality of receivers is configured to substantially achieve the first level of performance.

9. A wireless communication system comprising:

a first processing circuit configured to identify a first receiver from a plurality of receivers, the first receiver being configured to substantially achieve a first predetermined level of performance, wherein a transmitter is configured to transmit data to the first receiver over a first spatial subchannel of a communication channel using a first frequency subcarrier at a first power level that is sufficient to substantially achieve a first signal-to-noise ratio at the first receiver;

a second processing circuit configured to identify a second receiver from the plurality of receivers, the second receiver being configured to substantially achieve a second predetermined level of performance, wherein the transmitter is configured to transmit data to the second receiver over a second spatial subchannel of the communication channel using a second frequency subcarrier at a second power level that is sufficient to substantially achieve a second signal-to-noise ratio at the second receiver, wherein a sum of the first power level and the second power level is less than a predetermined maximum power level, and wherein the first spatial subchannel is spatially compatible with the second spatial subchannel; and

a third processing circuit configured to schedule the transmitter to communicate with the first receiver over the first spatial subchannel and to communicate with the second receiver over the second spatial subchannel substantially concurrently, wherein the first frequency subcarrier is the same as the second frequency subcarrier.

10. The system of claim 9, wherein the first spatial subchannel is spatially compatible with the second spatial subchannel when the first spatial subchannel achieves a first predetermined throughput level and the second spatial subchannel achieves a second predetermined throughput level during substantially concurrent transmission over the first spatial subchannel and the second spatial subchannel.

11. The system of claim 10, wherein the sum of the first predetermined throughput level and the second predetermined throughput level is maximized.

12. The system of claim 9, wherein the first spatial subchannel comprises a first propagation path between the first receiver and the transmitter, the second spatial subchannel comprises a second propagation path between the second receiver and the transmitter, and the first propagation path is different than the second propagation path.

13. The system of claim 9, wherein the first predetermined level of performance comprises a first difference between a first setpoint signal-to-noise ratio of the first receiver and a first actual signal-to-noise ratio achievable at the first receiver during communication with the transmitter, and the second predetermined level of performance comprises a second difference between a second setpoint signal-to-noise ratio of the second receiver and a second actual signal-to-noise ratio achievable at the second receiver during communication with the transmitter.

14. The system of claim 9, wherein the first level of performance is substantially equal to the second level of performance.

15. A wireless communication system comprising:

means for identifying a first receiver from a plurality of receivers, the first receiver being configured to substantially achieve a first predetermined level of performance, wherein a transmitter is configured to transmit data to the first receiver over a first spatial subchannel of a communication channel using a first frequency subcarrier at a first power level that is sufficient to substantially achieve a first signal-to-noise ratio at the first receiver;

means for identifying a second receiver from the plurality of receivers, the second receiver being configured to substantially achieve a second predetermined level of performance, wherein the transmitter is configured to transmit data to the second receiver over a second spatial subchannel of the communication channel using a second frequency subcarrier at a second power level that is sufficient to substantially achieve a second signal-to-noise ratio at the second receiver, wherein a sum of the first power level and the second power level is less than a predetermined maximum power level, and wherein the first spatial subchannel is spatially compatible with the second spatial subchannel; and

means for scheduling the transmitter to communicate with the first receiver over the first spatial subchannel and to communicate with the second receiver over the second spatial subchannel substantially concurrently, wherein the first frequency subcarrier is the same as the second frequency subcarrier.

16. The system of claim 15, wherein the first spatial subchannel is spatially compatible with the second spatial subchannel when the first spatial subchannel achieves a first predetermined throughput level and the second spatial subchannel achieves a second predetermined throughput level during substantially concurrent transmission over the first spatial subchannel and the second spatial subchannel.

17. The system of claim 16, wherein the sum of the first predetermined throughput level and the second predetermined throughput level is maximized.

18. The system of claim 15, wherein the first spatial subchannel comprises a first propagation path between the first receiver and the transmitter, the second spatial subchannel comprises a second propagation path between the second receiver and the transmitter, and the first propagation path is different than the second propagation path.

19. The system of claim 15, wherein the first predetermined level of performance comprises a first difference between a first setpoint signal-to-noise ratio of the first receiver and a first actual signal-to-noise ratio achievable at the first receiver during communication with the transmitter, and the second predetermined level of performance comprises a second difference between a second setpoint signal-to-noise ratio of the second receiver and a second actual signal-to-noise ratio achievable at the second receiver during communication with the transmitter.

20. A non-transitory computer readable medium including processor executable codes stored thereon, comprising:

code for causing a computer to identify a first receiver from a plurality of receivers, the first receiver being configured to substantially achieve a first predetermined level of performance, wherein a transmitter is configured to transmit data to the first receiver over a first spatial subchannel of a communication channel using a first frequency subcarrier at a first power level that is sufficient to substantially achieve a first signal-to-noise ratio at the first receiver;

code for causing a computer to identify a second receiver from the plurality of receivers, the second receiver being configured to substantially achieve a second predetermined level of performance, wherein the transmitter is configured to transmit data to the second receiver over a second spatial subchannel of the communication channel using a second frequency subcarrier at a second power level that is sufficient to substantially achieve a second signal-to-noise ratio at the second receiver, wherein a sum of the first power level and the second power level is less than a predetermined maximum power level, and wherein the first spatial subchannel is spatially compatible with the second spatial subchannel; and

code for causing a computer to schedule the transmitter to communicate with the first receiver over the first spatial subchannel and to communicate with the second receiver over the second spatial subchannel substantially concurrently, wherein the first frequency subcarrier is the same as the second frequency subcarrier.