Separating pilot signatures in a frequency hopping OFDM system by selecting pilot symbols at least hop away from an edge of a hop region

• US 7,768,979 B2
• Filed: 05/18/2005
• Issued: 08/03/2010
• Est. Priority Date: 05/18/2005
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Naguib, Ayman Fawzy, Gorokhov, Alexei, Sutivong, Arak, Ji, Tingfang, Gore, Dhananjay
• Primary Examiner(s): Corsaro; Nick
• Assistant Examiner(s): Magloire; Vladimir
• Application Number:
  US11/132,765
• Publication Number:
  US 20060291371A1
• Time in Patent Office: 1,903 Days
• Field of Search: 455/442, 455/443, 455/450, 375132-137, 370329-334
• US Class Current: 370/334
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0491 using two or more sectors, i.e. sector diversity
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0012 Hopping in multicarrier systems for frequency hopping in spread spectrum systems H04B1/713
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0069 Allocation based on distance or geographical location allocation based on terminal or device properties in general, H04W72/51
• CPC Class Codes: H04W 36/00692 using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] allocation of physical resources in CoMP or in CA H04L5/0035
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00

Abstract

Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The patterns may be selected according to a location of the mobile station with respect to one or more antennas are provided. In some aspects, the pattern may be selected based upon the distance between the mobile station and the one or more antennas. In other aspect, the pattern may be based upon whether the mobile station is in handoff.

Claims

1. A wireless communication apparatus, comprising:

a plurality of antenna groups each of which corresponds to a one of a plurality of sectors within a cell, wherein each of the plurality of sectors comprises a different area radially extending from the plurality of antenna groups;

a memory that stores a plurality of indicators each corresponding to a contiguous group of adjacent pilot symbols of a plurality of groups of pilot symbols in a hop region of pilot symbols for performing time-frequency hopping by a plurality of wireless communication devices during communication with the wireless communication apparatus; and

a circuit coupled with the plurality of antenna groups that selects an indicator of the plurality of indicators, to be transmitted to a wireless communication device in communication with one of the plurality of antenna groups based upon a location of the wireless communication device within a respective one of the plurality of sectors, to assign the wireless communication device to transmit using time-frequency hopping a group of pilot symbols to the wireless communication apparatus, wherein the contiguous group of adjacent pilot symbols corresponding to the indicator are selected at least one hop away from an edge of the hop region and allow the antenna group in the sector in which the wireless communication device is located to separate pilot signatures of different wireless communication devices overlapping on the same hop region.

2. The wireless communication apparatus of claim 1, wherein the circuit selects a specific one of the indicators when the wireless communication device is near a boundary between two or more of the plurality of sectors.

3. The wireless communication apparatus of claim 2, wherein the wireless communication apparatus decodes a same symbol received, at antennas from two different groups of the antenna groups, from the wireless communication device.

4. The wireless communication apparatus of claim 2, wherein the circuit selects the specific one of the indicators, to be transmitted to a second wireless communication device in communication with one of the plurality of antenna groups, when the second wireless communication device is near a boundary between two or more of the plurality of sectors.

5. The wireless communication apparatus of claim 2, wherein the circuit selects a second specific indicator, to be transmitted to a. second wireless communication device in communication with one of the plurality of antenna groups, when the second wireless communication device is near a boundary between another two or more of the plurality of sectors that are different than the two or more of the plurality of sectors.

6. The wireless communication apparatus of claim 2, wherein each group of pilot symbols correspond to a different scrambling sequence of a plurality of scrambling sequences and wherein a group corresponding to the specific one of the indicators corresponds to a pre-determined scrambling sequence based upon the location.

7. The wireless communication apparatus of claim 2, wherein each group of pilot symbols correspond to a pattern of pilot symbol locations of a plurality of patterns of pilot symbol locations and wherein a group corresponding to the specific one of the indicators corresponds to a pre-determined pattern of pilot symbol locations that are based upon the location of the wireless communication device.

8. The wireless communication apparatus of claim 1, wherein the circuit comprises a processor.

9. The wireless communication apparatus of claim 1, wherein the wireless communication apparatus transmits signals according to an OFDM communication protocol.

10. The wireless communication apparatus of claim 1, wherein the circuit further utilizes quality of service requirements to select the indicator of the plurality of indicators.

11. The wireless communication apparatus of claim 1, wherein the circuit determines the location of the wireless communication device based upon channel quality information received from the wireless communication device.

12. The wireless communication apparatus of claim 1, wherein the plurality of groups of pilot symbols are each orthogonal to each other.

13. The wireless communication apparatus of claim 1, wherein the circuit decodes data symbols associated with the pilot symbols received at each of the plurality of antenna groups for each of the group of pilot symbols of the plurality of groups of pilot symbols and then combines decoded data symbols for a same group of pilot symbols received at each of the plurality of antenna groups.

14. The wireless communication apparatus of claim 1, wherein the circuit is further configured to select the contiguous group of pilot symbols from a plurality of contiguous groups of pilot symbols symmetric with respect to a center of the hop region.

15. A method of selecting a pilot pattern for a wireless communication device comprising:

determining a location of a wireless communication device with respect to an antenna of a plurality of antennas, wherein each of the plurality of antennas corresponds to one of a plurality of sectors of a cell, wherein each of the plurality of sectors comprises a different area radially extending from the plurality of antennas;

selecting a contiguous pilot pattern of adjacent pilot symbols of a plurality of pilot patterns in a hop region of pilot patterns to be utilized for time-frequency hopping transmission by the wireless communication device based upon the location, wherein the contiguous pilot pattern is selected at least one hop away from an edge of the hop region and allows the antenna in the sector in which the wireless communication device is located to separate pilot signatures of different wireless communication devices overlapping on the same hop region; and

transmitting an indicator of the pilot pattern to the wireless communication device.

16. The method of claim 15, further comprising determining a location of the wireless communication device with respect to another antenna, and wherein selecting the pilot pattern comprises selecting the pilot pattern based upon the location with respect to the antenna and the location with respect to the another antenna.

17. The method of claim 16, wherein determining the location with respect to the antenna comprises determining a distance between the antenna and the wireless communication device and determining the location with respect to the another antenna comprises determining a distance between the another antenna and the wireless communication device.

18. The method of claim 15, wherein determining the location comprises determining the location based upon channel quality information.

19. The method of claim 18, wherein determining the location based upon channel quality information comprises determining a noise level.

20. The method of claim 18, wherein determining the location based upon channel quality information comprises determining a signal to noise ratio.

21. The method of claim 15, wherein determining the location comprises determining the location with respect to a sector boundary.

22. The method of claim 21, wherein selecting the pilot pattern comprises selecting an edge pilot pattern if the location is sufficiently close to the sector boundary.

23. The method of claim 15, wherein determining the location with respect to the antenna comprises determining a distance between the antenna and the wireless communication device.

24. The method of claim 15, wherein determining the distance comprises comparing a signal to noise ratio to a reference.

25. The method of claim 15, wherein selecting comprises selecting the pilot pattern based upon the location and based on a respective one of the plurality of antennas with which the wireless communication device is currently communicating.

26. The method of claim 15, wherein each pilot pattern of the plurality of pilot patterns is orthogonal with respect to each other pilot pattern of the plurality of pilot patterns.

27. The method of claim 15, wherein each pilot pattern of the plurality of pilot patterns is assigned a different scrambling sequence of a plurality of scrambling sequence than each other pilot pattern of the plurality of pilot patterns.

28. The method of claim 15, wherein selecting the contiguous pilot pattern is from a plurality of contiguous pilot patterns symmetric with respect to a center of the hop region.

29. A wireless communication apparatus comprising:

means for determining a location of a wireless communication device with respect to an antenna of a plurality of antennas, wherein each of the plurality of antennas corresponds to one of a plurality of sectors of a cell, wherein each of the plurality of sectors comprises a different area radially extending from the plurality of antennas;

means for selecting a contiguous pilot pattern of adjacent pilot symbols of a plurality of pilot patterns in a hop region of pilot patterns to be utilized for time-frequency hopping transmission by the wireless communication device based upon the location, wherein the contiguous pilot pattern is selected at least one hop away from an edge of the hop region and allows the antenna in the sector in which the wireless communication device is located to separate pilot signatures of different wireless communication devices overlapping on the same hop region; and

means for transmitting an indicator of the pilot pattern to the wireless communication device.

30. The wireless communication apparatus of claim 29, further comprising means for determining a location of the wireless communication device with respect to another antenna of the wireless communication apparatus, and wherein the means for selecting comprises means for selecting the pilot pattern based upon the location with respect to the antenna and the location with respect to the another antenna.

31. The wireless communication apparatus of claim 30, wherein the means for determining the location with respect to the antenna comprises means for determining a distance between the antenna and the wireless communication device and the means for determining the location with respect to the another antenna comprises means for determining a distance between the another antenna and the wireless communication device.

32. The wireless communication apparatus of claim 29, wherein the means for determining the location comprises means for determining the location based upon channel quality information.

33. The wireless communication apparatus of claim 29, wherein the means for determining the location comprises means for determining the location with respect to a sector boundary.

34. The wireless communication apparatus of claim 29, wherein each pilot pattern of the plurality of pilot patterns is orthogonal with respect to each other pilot pattern of the plurality of pilot patterns.

35. The wireless communication apparatus of claim 29, wherein each pilot pattern of the plurality of pilot patterns is assigned a different scrambling sequence of a plurality of scrambling sequence than each other pilot pattern of the plurality of pilot patterns.

36. The wireless communication apparatus of claim 29, further comprising means for decoding data symbols received at each of the plurality of antenna groups associated with each of the pilot pattern of the plurality of pilot patterns and means for combining decoded symbols associated with a same pilot pattern received at each of the plurality of antenna groups.

37. The wireless communication apparatus of claim 29, wherein the means for selecting is further configured to select the contiguous group of pilot symbols from a plurality of contiguous groups of pilot symbols symmetric with respect to a center of the hop region.

38. A wireless communication apparatus, comprising:

a plurality of antenna groups each corresponding to one of a plurality of sectors of a cell, wherein each of the plurality of sectors comprises a different area radially extending from the plurality of antenna groups;

a memory that stores a plurality of indicators each corresponding to a contiguous pilot pattern of adjacent pilot symbols of a plurality of pilot patterns in a hop region of pilot patterns to be used for time-frequency hopping by a plurality of wireless communication devices communicating with the wireless communication apparatus; and

a circuit coupled with the plurality of antenna groups that selects an indicator of the plurality of indicators, to be transmitted to a wireless communication device in communication with one of the plurality of antenna groups based upon which antenna group is in communication with the wireless communication device, wherein the contiguous pilot pattern is selected at least one hop away from an edge of the hop region and allows the antenna in the sector in which the wireless communication device is located to separate pilot signatures of different wireless communication devices overlapping on the same hop region.

39. The wireless communication apparatus of claim 38, wherein the wireless communication apparatus decodes pilot symbols received, at antennas from two different groups of the antenna groups, from the wireless communication device.

40. The wireless communication apparatus of claim 38, wherein the circuit selects a second specific indicator, to be transmitted to a second wireless communication device in communication with one of the plurality of antenna groups, when the second wireless communication device is in communication with a different antenna group than the wireless communication device.

41. The wireless communication apparatus of claim 40, wherein the at least two pilot patterns are different between each antenna group.

42. The wireless communication apparatus of claim 38, wherein the circuit comprises a processor.

43. The wireless communication apparatus of claim 38, wherein the wireless communication apparatus transmits signals according to an OFDM communication protocol.

44. The wireless communication apparatus of claim 38, wherein at least two pilot patterns are assigned for communication between wireless communication devices and each antenna group.

45. The wireless communication apparatus of claim 38, wherein only one pilot pattern is assigned for communication between wireless communication devices and each antenna group.

46. The wireless communication apparatus of claim 38, wherein the circuit decodes pilot symbols received at each of the plurality of antenna groups for each pilot pattern of the plurality of pilot patterns and then combines decoded pilot symbols for a same pilot pattern received at each of the plurality of antenna groups.

47. The wireless communication apparatus of claim 38, wherein the circuit is further configured to select the contiguous pilot pattern from a plurality of contiguous pilot patterns symmetric with respect to a center of the hop region.