SDMA resource management

• US 20070097910A1
• Filed: 10/27/2005
• Published: 05/03/2007
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gorokhov, Alexei, Agrawal, Avneesh, Dong, Min, Ji, Tingfang, Gore, Dhananjay
• Granted Patent: US 8,693,405 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 72/563 of the wireless resources

Abstract

A method for allocating resources in a wireless communications environment comprises receiving a mapping between a first hop-port and frequency range, and determining whether to map a second access terminal to a second hop-port that is mapped to at least the same frequency range during a substantially similar instance in time, the determination made as a function of characteristics relating to a first access terminal associated with the first hop-port. The method can further include determining that the first access terminal is a candidate for employing Space-Division Multiple Access (SDMA), and mapping the second-hop port and associating the second access terminal with the second hop-port when the second access terminal is also a candidate for employing SDMA.

Claims

1. A method for allocating resources in a wireless communications environment, comprising:

receiving a mapping between a first hop-port and frequency range; and

determining whether to assign a second access terminal to a second hop-port that is mapped to at least the same frequency range during a substantially similar instance in time, the determination made as a function of characteristics relating to a first access terminal associated with the first hop-port.

2. The method of claim 1, further comprising:

determining that the first access terminal is a candidate for employing Space-Division Multiple Access (SDMA); and

mapping the second-hop port and associating the second access terminal with the second hop-port when the second access terminal is also a candidate for employing SDMA.

3. The method of claim 2, wherein a first channel tree includes multiple mappings between hop-ports and frequency ranges, the first channel tree further includes the first hop-port, and a second channel tree includes multiple mappings between hop-ports and frequency ranges, the second channel tree further includes the second hop-port.

4. The method of claim 1, further comprising:

determining that the first access terminal is not a candidate for employing SDMA; and

preventing mapping of the second-hop port.

5. The method of claim 1, wherein a first channel tree includes multiple mappings between hop-ports and frequency ranges according to a first hop permutation and a second channel tree includes multiple mappings between hop-ports and the frequency ranges according to the first hop permutation.

6. The method of claim 5, further comprising:

determining that the first access terminal has a first spatial direction;

determining that a second access terminal has a second spatial direction;

mapping the first access terminal to the first hop-port for a first time period; and

mapping the second access terminal to the second hop-port for the first time period.

7. The method of claim 6, further comprising:

associating the first access terminal with a first plurality of hop-ports in the first channel tree; and

preventing association of a third access terminal to the first plurality of hop-ports in the second channel tree.

8. The method of claim 7, further comprising determining that the third access terminal is operating in a diversity mode, and wherein preventing comprises preventing associating when the third access terminal is operating in the diversity mode.

9. The method of claim 7, wherein each hop port is mapped to a range of frequencies, the method further comprising:

randomly mapping the first plurality of hop-ports to frequencies within the range of frequencies; and

randomly mapping the second plurality of hop-ports to frequencies within the range of frequencies.

10. The method of claim 6, further comprising:

receiving a quantized value indicative of the first direction from the first access terminal; and

associating the first access terminal to the first hop-port based upon the quantized value.

11. The method of claim 10, wherein the quantized value is selected from a codebook.

12. The method of claim 1, further comprising receiving channel information from the first access terminal and wherein determining comprises determining based upon the channel information.

13. The method of claim 12, wherein the channel information comprises a Channel Quality Indicator.

14. A wireless communications apparatus, comprising:

a memory that includes information relating to whether two access terminals are candidates for employing SDMA in an OFDM/OFDMA environment; and

a processor that assigns the two access terminals to two hop-ports that are mapped to substantially similar frequencies in a sector at substantially similar times if the two access terminals are candidates for employing SDMA.

15. The wireless communications apparatus of claim 14, wherein a first channel tree includes mappings between multiple hop-ports and multiple frequency ranges according to a hop permutation, the processor defines mappings associated with a second channel tree as a function of the hop permutation.

16. The wireless communications apparatus of claim 14, the processor performs the mapping for a forward-link.

17. The wireless communications apparatus of claim 14, the processor receives packets from the two access terminals and determines whether the two access terminals are candidates for employing SDMA on a per-packet basis.

18. The wireless communications apparatus of claim 14, the processor is associated with multiple transmit antennas that are employed to effectuate communications between an access point and the two access terminals.

19. An apparatus for managing frequency resources in a wireless communications environment, comprising:

means for determining that a first access terminal and a second access terminal are candidates for employing SDMA; and

means for assigning the first access terminal to a first hop-port and the second access terminal to a second hop-port, the first and second hop-ports are mapped to substantially similar time-frequency resources.

20. The apparatus of claim 19, further comprising:

means for analyzing a first channel tree that includes the mapping between the first hop-port and the time-frequency resources; and

means for defining the mapping between the second hop-port and the time-frequency resources in a second channel tree.

21. The apparatus of claim 19, further comprising:

means for maintaining a codebook, the codebook includes information relating to a quantized value indicative of a first spatial direction associated with the first access terminal; and

means for defining mappings associated with the first channel tree and the second channel tree as a function of the quantized value.

22. The apparatus of claim 19, further comprising:

means for determining that a third access terminal is not a candidate for employing SDMA; and

means for ensuring that the third access terminal does not share time-frequency resources with other access terminals.

23. The apparatus of claim 19, further comprising:

means for mapping a first plurality of hop-ports to a set of frequencies within a range of frequencies; and

means for mapping a second plurality of hop-ports to the set of frequencies within the range of frequencies so that a hop-port within the first plurality of hop-ports and a corresponding hop-port within the second plurality of hop-ports are mapped to corresponding frequencies within the set of frequencies.

24. The apparatus of claim 19, further comprising:

means for randomly mapping a first plurality of hop-ports to a set of frequencies within a range of frequencies; and

means for randomly mapping a second plurality of hop-ports corresponding to the first set of hop-ports to the set of frequencies within the range of frequencies so that corresponding hop-ports within the first set of hop-ports and the second set of hop-ports are not mapped to substantially similar frequencies.

25. A computer-readable medium having stored thereon computer-executable instructions for:

determining that a first access terminal is a candidate for employing SDMA;

assigning the first access terminal to one or more hop-ports that are mapped to one or more frequency tones in a first channel tree;

determining that a second access terminal is a candidate for employing SDMA;

assigning the second access terminal to one or more hop-ports; and

mapping the one or more hop-ports assigned to the second access terminal to the one or more frequency tones mapped to the one or more hop-ports assigned to the first access terminal in a second channel tree.

26. The computer-readable medium of claim 25, further comprising instructions for determining that the first access terminal is separated in space a sufficient distance from the second access terminal to enable the first access terminal and the second access terminal to share time-frequency resources.

27. The computer-readable medium of claim 25, further comprising instructions for:

determining that a third access terminal is not a candidate for employing SDMA;

assigning the third access terminal to one or more hop-ports within the first channel tree; and

ensuring that hop-ports within the second channel tree that correspond to hop-ports within the first channel tree associated with the third access terminal are not assigned to a disparate access terminal.

28. The computer-readable medium of claim 27, further comprising instructions for:

randomly mapping the one or more hop-ports associated with the first access terminal to the one or more frequency tones; and

randomly mapping the one or more hop-ports associated with the second access terminal to the one or more frequency tones.

29. A processor that executes instructions for enhancing performance for a wireless communication environment, the instructions comprising:

associating a first access terminal to a first set of hop-ports, the first access terminal configured to operate in an OFDM/OFDMA environment, the first access terminal is a candidate for employment of SDMA;

mapping the first set of hop-ports to a range of frequencies;

associating a second access terminal to a second set of hop-ports, the second access terminal configured to operate in an OFDM/OFDMA environment, the second access terminal is a candidate for employment of SDMA; and

mapping the second set of hop-ports to the range of frequencies so that the first set of hop-ports and the second set of hop-ports are mapped to the range of frequencies at a substantially similar time.

30. The processor of claim 29, the instructions further comprise ensuring that the first and second access terminal are separated in space a threshold distance.