Base station beam sweeping method and apparatus using multiple rotating antennas

• US 6,757,553 B1
• Filed: 10/14/1999
• Issued: 06/29/2004
• Est. Priority Date: 10/14/1999
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: English, Sean S.
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US09/419,682
• Time in Patent Office: 1,720 Days
• Field of Search: 455/561, 455/562, 455/103, 455/133, 455/136, 455/277.1, 342/158, 342/368, 342/374, 342/428, 342/430, 342/367, 343/757, 343/758, 343/766
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/04 for varying one co-ordinate of the orientation
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0491 using two or more sectors, i.e. sector diversity
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

A method and apparatus for wireless communications wherein a base station transmits and receives wireless signals through multiple directional antennas mounted on a rotating antenna assembly. Signal beams from each directional antenna sweep in one angular direction through multiple sector coverage areas. As a signal beam crosses from one sector to another, the routing of forward and reverse link signals associated with that signal beam are switched from the sector it is exiting to the sector it is entering.

Claims

1. Wireless communication base station comprising:

an antenna assembly comprising a first predetermined number of directional antennas, wherein said first predetermined number of directional antennas are assembled into said antenna assembly such that the radiation pattern of each said antenna is directed radially outward from the center of said antenna assembly;

a motor, mechanically connected to said antenna assembly, for rotating said antenna assembly continuously in one direction about its axis; and

a signal switch for routing signals between each of said directional antennas and a second predetermined number of sector connections.

2. The base station of claim 1 further comprising broad beam antenna for transmitting a pilot channel signal, wherein said pilot channel signal is transmitted coherently with respect to signals transmitted through said antenna assembly.

3. The base station of claim 1 wherein said signal switch is a digital signal switch.

4. The base station of claim 1 wherein said directional antennas are 30-degree half-power antennas.

5. The base station of claim 1 wherein said directional antennas are dish antennas.

6. The base station of claim 1 wherein said directional antennas are collinear array antennas.

7. The base station of claim 1 wherein said first predetermined number is greater than three.

8. The base station of claim 1 further comprising high power amplifier for amplifying an analog RF signal to produce an amplified signal, and wherein said signal switch routes said amplified signal from said high power amplifier to said directional antennas.

9. The base station of claim 1 further comprising control processor for generating a sector routing signal, and wherein said signal switch routes signals from at least one of said sector connections to each said directional antenna based on said sector routing signal.

10. The base station of claim 1 wherein said first predetermined number is three.

11. The base station of claim 10 wherein said radiation patterns project out from said antenna assembly at approximately 120 degrees from each other.

12. The base station of claim 1 wherein said second predetermined number is three.

13. The base station of claim 12 wherein said first predetermined number is six.

14. The base station of claim 1 further comprising said first predetermined number of high power amplifiers, wherein each high power amplifier is disposed between one of said directional antennas and said signal switch, and wherein each said high power amplifier receives an analog RF signal from said signal switch and amplifying said analog RF signal to produce an amplified signal.

15. The base station of claim 14 further comprising one or more CDMA finger demodulators for receiving a downconverted reverse link sample stream from said at least one of said sector connections and performing PN despreading of said downconverted reverse link sample stream to produce a PN despread reverse link signal.

16. The base station of claim 14 further comprising said first predetermined number of transmitters, wherein each transmitter is disposed between one of said high power amplifiers and said signal switch, for receiving a baseband signal from said signal switch and upconverting said baseband signal to produce said analog RF signal.

17. The base station of claim 14 further comprising control processor for generating a sector routing signal, and wherein said signal switch routes signals from at least one of said sector connections to each said directional antenna based on said sector routing signal.

18. The base station of claim 17 wherein said motor provides an angular position signal to said control processor, and wherein said sector routing signal is based on said angular position signal.

19. The base station of claim 17 wherein said Walsh code is a supplemental channel Walsh code.

20. The base station of claim 14 further comprising pseudonoise (PN) spreader for performing PN spreading of a first data signal to produce a PN spread signal, and for providing said PN spread signal to said at least one of said sector connections for routing by said signal switch.

21. The base station of claim 20 wherein said PN spreader is a real PN spreader for multiplying said first data signal by a real PN code.

22. The base station of claim 20 wherein said PN spreader is a complex PN spreader for multiplying said first data signal by a complex PN code.

23. The base station of claim 20 further comprising broad beam antenna, wherein said PN spreader further spreads a pilot signal to produce a PN spread pilot signal, and wherein said PN spread pilot signal is transmitted through said broad beam antenna.

24. The base station of claim 20 further comprising Walsh spreader for receiving a second data signal and multiplying it by a Walsh code to produce said first data signal.

25. A method of transmitting an information signal comprising:

routing one forward link signal of a first predetermined number of forward link signals to a first directional antenna of a second predetermined number of directional antennas, wherein said second predetermined number of directional antennas are assembled into an antenna assembly such that the radiation pattern of each of said second predetermined number of directional antennas is directed radially outward from the center of said antenna assembly, and wherein said routing is based on an angular position of said first directional antenna;

rotating said antenna assembly continuously in one direction; and

transmitting said one forward link signal through a signal beam corresponding to said first directional antenna.

26. The method of claim 25 further comprising transmitting a pilot channel signal through a broad signal beam, wherein said pilot channel signal is coherent with respect to at least one of said first predetermined number of forward link signals.

27. The method of claim 25 further comprising routing said one forward link signal to a second directional antenna of said second predetermined number of directional antennas based on the sweeping of said signal beam over a boundary between two of said first predetermined number of sector coverage areas.

28. The method of claim 25 wherein said first directional antenna is a dish antenna.

29. The method of claim 25 wherein said first directional antenna is a collinear array antenna.

30. The method of claim 25 wherein said second predetermined number is greater than three.

31. The method of claim 25 wherein said second predetermined number is three.

32. The method of claim 31 wherein said directional antennas are directed radially outward from an axis at approximately 120 degree angles from each other.

33. The method of claim 25 wherein said first predetermined number is three.

34. The method of claim 33 wherein said first predetermined number is six.

35. The method of claim 25 further comprising pseudonoise (PN) spreading a PN despread signal to form said one forward link signal.

36. The base station of claim 35 wherein said PN spreading is real PN spreading, wherein said PN despread signal is multiplied by a real PN code.

37. The base station of claim 35 wherein said PN spreading is complex PN spreading, wherein said PN despread signal is multiplied by a complex PN code.

38. The method of claim 35 further comprising Walsh spreading a Walsh despread signal using a Walsh code to form said PN despread signal.

39. The method of claim 38 wherein said Walsh code is a supplemental channel Walsh code.

40. A method of receiving an information signal comprising:

receiving a first reverse link signal through a first signal beam corresponding to a first directional antenna of a first predetermined number of directional antennas, wherein said first predetermined number of directional antennas are assembled into an antenna assembly such that the radiation pattern of each of said first predetermined number of directional antennas is directed radially outward from the center of said antenna assembly;

rotating said antenna assembly continuously in one direction; and

routing, based on an angular position of said first predetermined number of directional antennas, said first reverse link signal to a finger demodulator through a first sector connection of a second predetermined number of sector connections.

41. The method of claim 40 further comprising adjusting said routing of said first reverse link signal such that it is routed through a second sector connection when said signal beam sweeps over the boundary between two of said second predetermined number of sector coverage areas.

42. The method of claim 40 wherein said one directional antenna is a dish antenna.

43. The method of claim 40 wherein said one directional antenna is a collinear array antenna.

44. The method of claim 40 wherein said first predetermined number is greater than three.

45. The method of claim 40 wherein said first predetermined number is three.

46. The method of claim 45 wherein said first predetermined number of directional antennas are directed radially outward from an axis at approximately 120 degree angles from each other.

47. The method of claim 40 wherein said second predetermined number is three.

48. The method of claim 47 wherein said first predetermined number is six.

49. The method of claim 40 further comprising pseudonoise (PN) despreading said first reverse link signal to form a PN despread signal.

50. The base station of claim 49 wherein said PN despreading is real PN despreading, wherein said first reverse link signal is multiplied by a real PN code.

51. The base station of claim 50 wherein said PN despreading is complex PN despreading, wherein said first reverse link signal is multiplied by a complex PN code.

52. The method of claim 50 further comprising Walsh despreading said PN despread signal using a Walsh code to form a Walsh despread signal.

53. The method of claim 52 wherein said Walsh code is a supplemental channel Walsh code.