Embedded digital beam switching

• US 6,055,230 A
• Filed: 09/05/1997
• Issued: 04/25/2000
• Est. Priority Date: 09/05/1997
• Status: Expired due to Term

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Metawave Communications Corp.
• Inventors: Li, Yingjie, Reynolds, Sheila, Reudink, Douglas O., Feuerstein, Martin J., Reudink, Mark
• Primary Examiner(s): Vu, Huy D.
• Assistant Examiner(s): Kwoh, Jasper
• Application Number:
  US08/924,741
• Time in Patent Office: 963 Days
• Field of Search: 370/320, 370/334, 370/335, 370/342, 370/441, 455/562, 455/25, 455/561, 342/354, 342/359, 342/374
• US Class Current: 370/335
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• 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: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0802 using antenna selection H04B7/0868 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming

Abstract

Disclosed is a system utilizing a multi-beam antenna and switches the beams to a CDMA demodulation receiver in such a way that the best beams are selected. The transmit path takes the traffic channel outputs from the CDMA modulators and maps each traffic channel to the subset of beams that have the best path to the mobile in the forward link. According, the system operates to reduce interference on both the forward and reverse links, as well as to increase the capacity of both the forward and reverse links. The system also is capable of providing flexible dynamic shaping of the cell and the sectors by mapping the appropriate overhead channels on the forward link and the reverse link in different combinations of beams to sectors in order to shape the cell.

Claims

1. A multi-sectored CDMA receiver system having a plurality of CDMA channels associated therewith and utilizing a multi-beam antenna having a plurality of predefined narrow beams, each beam having a receive signal associated therewith for input into a demodulation input of a plurality of demodulation inputs of a CDMA receiver, wherein ones of said plurality of demodulation inputs are associated with ones of said sectors, said system comprising:

means for switchably providing any of said beam receive signals to select ones of said demodulation inputs, wherein said switchably providing means includes a plurality of independently operable switching circuits each assigned to a different one of said CDMA channels; and

means for controlling said switchably providing means, said controlling means providing a signal to each of said independently operable switching circuits utilized in causing said switching circuits to allow only a select subset of said beam receive signals to pass to a demodulation input of the plurality of demodulation inputs each associated with a particular switching circuit of the plurality of independently operable switching circuits.

2. The system of claim 1, wherein said subset of beam receive signals is selected as a function of channel search data associated with ones of said beam receive signals.

3. The system of claim 2, wherein said measurements of said channel search data is provided by a channel element controller in communication with said controlling means.

4. The system of claim 1, wherein said subset of beam receive signals is selected as a function of a comparison of measurements of a signal interference ratio of at least a portion of ones of said beam receive signals.

5. The system of claim 4, wherein said measurements of said signal interference ratio is provided by a channel element controller in communication with said controlling means.

6. The system of claim 1, wherein said switchably providing means comprise:

a plurality of digital switch multiplexers each associated with a particular one of said CDMA channels.

7. The system of claim 6, wherein said digital switch multiplexers are each coupled to a different channel element of said CDMA receiver.

8. The system of claim 1, further comprising:

means for isolating overhead channels present in ones of said beam receive signals and for providing said isolated overhead channels to a cell site processor.

9. The system of claim 8, wherein an azimuthal size of at least one of said sectors is dynamically adjustable as a function of a number of said beams associated with ones of said overhead channels by said cell site processor.

10. The system of claim 1, wherein said select subset of beam receive signals comprises 6 beam receive signals.

11. The system of claim 10, wherein a number of said plurality of predefined narrow beams is 12, and wherein said narrow beams are disposed to provide substantially non-overlapping coverage throughout a cell associated with said CDMA receiver.

12. The system of claim 1, further comprising:

means for independently converting each of said beam receive signals from a received radio frequency to a preselected intermediate frequency; and

means for independently converting each of said beam receive signals from an analogue signal to a digital signal.

43. The system of claim 1, wherein said signals provided to said switching circuits by said controlling means cause said switchably providing means to define different coverage patterns based on a type of channel communicated therein.

44. The system of claim 43, wherein said types of channel communicated includes at least two types of channels selected from the group consisting of:

a traffic channel;

an overhead channel;

a pilot synchronization channel; and

a paging channel.

45. The system of claim 43, wherein a first type of channel communicated is a traffic channel and said beam receive signals provided to a demodulation input associated with said traffic channel are beam receive signals selected for providing a best link, and wherein a second type of channel communicated is a control channel and said beam receive signals provided to a demodulation input associated with said control channel are beam receive signals selected to define a sector associated with said control channel.

46. The system of claim 1, wherein said signals provided to said switching circuits by said controlling means couple different numbers of said beam receive signals to different ones of said demodulation inputs.

13. A multi-sectored CDMA transmitter system having a plurality of CDMA channels associated therewith and utilizing a multi-beam antenna having a plurality of predefined narrow beams, each beam having a transmit signal associated therewith for radiation of at least one output of a plurality of modulation outputs of a CDMA transmitter, wherein ones of said plurality of modulation outputs are associated with ones of said sectors, said system comprising:

means for switchably providing any one of said modulation transmitter outputs to any of said beam transmit signals, wherein said switchably providing means includes a plurality of independently operable switching circuits each assigned to a different one of said CDMA channels; and

means for controlling said switchably providing means, said controlling means providing a signal to each of said independently operable switching circuits utilized in causing said switching circuits to allow each of said modulation transmitter outputs to pass only to a select subset of said beam transmit signals.

14. The system of claim 13, wherein said subset of said beam transmit signals is selected as a function of channel search data associated with ones of a plurality of receive signals.

15. The system of claim 14, wherein said measurements of said channel search data is provided by a channel element controller in communication with said controlling means.

16. The system of claim 13, wherein said subset of beam transmit signals is selected as a function of a comparison of measurements of a signal interference ratio of at least a portion of ones of a plurality of receive signals.

17. The system of claim 16, wherein said measurements of said signal interference ratio is provided by a channel element controller in communication with said controlling means.

18. The system of claim 13, further comprising:

means for providing an overhead channel to select ones of said beam transmit signals, said overhead channel providing means operable with said switchably providing means to combine signals associated with ones of said modulation transmitter outputs switchably provided to said select ones of said beam transmit signals with said overhead channel.

19. The system of claim 18, wherein an azimuthal size of at least one of said sectors is dynamically adjustable as a function of a number of said beams provided said overhead channel.

20. The system of claim 13, wherein said select subset of beam transmit signals comprises 2 beam transmit signals.

21. The system of claim 20, wherein a number of said plurality of predefined narrow beams is 12, and wherein said narrow beams are disposed to provide substantially non-overlapping coverage throughout a cell associated with said CDMA transmitter.

22. The system of claim 13, further comprising:

means for independently converting each of said beam transmit signals from a digital signal to an analogue signal; and

means for independently converting each of said beam transmit signals from an intermediate frequency to a preselected radio frequency.

47. The system of claim 13, wherein said signals provided to said switching circuits by said controlling means cause said switchably providing means to define different coverage patterns based on a type of channel communicated therein.

48. The system of claim 47, wherein said types of channel communicated includes at least two types of channels selected from the group consisting of:

a traffic channel;

an overhead channel;

a pilot synchronization channel; and

a paging channel.

49. The system of claim 47, wherein a first type of channel communicated is a traffic channel and said beam transmit signals coupled to said modulation transmitter output associated with said traffic channel are beam transmit signals selected for providing a best link, and wherein a second type of channel communicated is a control channel and said beam transmit signals coupled to said modulation transmitter output associated with said control channel are beam transmit signals selected to define a sector associated with said control channel.

50. The system of claim 13, wherein said signals provided to said switching circuits by said controlling means couple different numbers of said beam transmit signals to different ones of said modulation outputs.

23. A system for utilizing a multi-beam antenna system having a plurality of predefined narrow beams with a multi-sectored CDMA base transceiver station utilizing a plurality of CDMA channels, each beam providing a beam input signal suitable for input into a demodulation receiver having a plurality of inputs, each beam also providing radiation of a beam output signal substantially within a predefined area, said beam output signals adapted to accept a signal output from a modulation transmitter having a plurality of outputs, wherein ones of said plurality of demodulation receiver inputs and ones of said plurality of modulation transmitter outputs are associated with ones of said sectors, said system comprising:

a baseband receive switch bank switchably providing any of said beam input signals to selected ones of said demodulation receiver inputs, wherein said baseband receive switch bank includes a plurality of independently operable receive switching circuits each assigned to a different one of said CDMA channels;

a baseband transmit switch bank switchably providing any of said modulation transmitter outputs to selected ones of said beam output signals, wherein said baseband transmit switch bank includes a plurality of independently operable transmit switching circuits each assigned to a different one of said CDMA channels; and

means for controlling said baseband receive switch bank and said baseband transmit switch bank.

24. The system of claim 23, further comprising:

means for dynamically adjusting a size of said sectors.

25. The system of claim 24, wherein said size of said sectors is adjusted by said adjusting means at least in part as a function of a number of said beam output signals switched to a control channel by said baseband transmit switch bank.

26. The system of claim 23, wherein ones of said plurality of independently operable receive switching circuits of said baseband receive switch bank comprise a digital switch multiplexer.

27. The system of claim 26, wherein said digital switch multiplexers are each coupled to a different channel element of said CDMA transceiver.

28. The system of claim 23, wherein said selected ones of said demodulation receiver inputs are selected by said baseband receive switch bank as a function of channel search data associated with ones of said beam input signals.

29. The system of claim 28, wherein said measurements of said channel search data is provided by a channel element controller in communication with said controlling means.

30. The system of claim 23, wherein said selected ones of said beam output signals are selected as a function of measurements of channel search data associated with ones of said beam input signals.

31. The system of claim 30, wherein said measurement of said channel search data is provided by a channel element controller in communication with said controlling means.

51. The system of claim 23, wherein said controlling means is adapted to dynamically control at least one of said baseband receive switch bank and said baseband transmit switch bank to define different coverage patterns for traffic channels and control channels.

32. A method for utilizing a multi-beam antenna having a plurality of predefined narrow beams with a multi-sectored CDMA base transceiver station utilizing a plurality of CDMA channels, each beam providing a beam input signal suitable for input into a demodulation receiver having a plurality of inputs, each beam also providing radiation of a beam output signal substantially within a predefined area, said beam output signals adapted to accept a signal output from a modulation transmitter having a plurality of outputs, wherein ones of said plurality of demodulation receiver inputs and ones of said plurality of modulation transmitter outputs are associated with ones of said sectors, said method comprising the steps of:

switchably inputting ones of said beam input signals to selected ones of said demodulation receiver inputs, wherein said switchably inputting step utilizes a plurality of independently operable input switching circuits each assigned to a different one of said CDMA channels, and wherein said independently operable input switching circuits are adapted to switchably provide any of said beam input signals to any of said demodulation receiver inputs;

switchably outputting ones of said modulation transmitter outputs to selected ones of said beam output signals, wherein said switchably outputting step utilizes a plurality of independently operable output switching circuits each assigned to a different one of said CDMA channels, and wherein said independently operable output switching circuits are adapted to switchably provide any of said modulation outputs to any of said beam output signals; and

controlling said input switching circuits and said output switching circuits as a function of channel search data associated with ones of said beam input signals.

33. The method of claim 32, further comprising the step of:

dynamically adjusting a size of said sectors.

34. The method of claim 33, further comprising the step of:

providing an overhead channel to select ones of said beam output signals, said overhead channel providing step combining signals associated with ones of said modulation outputs provided to said select ones of said beam output signals with said overhead channel.

35. The system of claim 34, wherein an azimuthal size of at least one of said sectors is adjusted at least in part as a function of a number of said beams provided said overhead channel.

36. The method of claim 32, wherein said measurements of said channel search data is provided by a channel element controller.

37. The method of claim 32, further comprising the steps of:

converting said beam input signals from a radio frequency to an intermediate frequency; and

converting said beam input signals from an analogue signal to a digital signal.

38. The method of claim 32, further comprising the steps of:

converting said beam output signals from a digital signal to an analogue signal; and

converting said beam output signals from an intermediate frequency to a radio frequency.

52. The method of claim 32, wherein said controlling step includes the step of:

controlling at least one of said input switching circuits and said output switching circuits to dynamically define different coverage patterns for traffic channels and control channels.

39. A system comprising:

a multi-sectored CDMA receiver having a plurality of CDMA channels associated therewith, wherein said CDMA receiver includes a plurality of demodulation inputs, wherein ones of said plurality of demodulation inputs are associated with ones of said sectors;

a multi-beam antenna having a plurality of substantially non-overlapping narrow beams, each beam having an antenna beam signal associated therewith;

a switch adapted to provide mapping of any of said antenna beam signals to select ones of said demodulation inputs, wherein said switch may be controlled to couple combinations of antenna beam signals to demodulation inputs including multiple antenna beam signals to a same demodulation input and multiple demodulation inputs to a same antenna beam signal; and

a controller coupled to said switch and providing signals to said switch to allow selective pluralities of said antenna beam signals to pass to each demodulation input of the plurality of demodulation inputs.

40. The system of claim 39, wherein an area of service associated with each sector of said multi-sectored CDMA receiver is defined by said selective pluralities of said antenna beam signals passed to demodulation inputs of the plurality of demodulation inputs.

41. A system comprising:

a multi-sectored CDMA transmitter having a plurality of CDMA channels associated therewith, wherein said CDMA transmitter includes a plurality of modulation outputs, wherein ones of said plurality of modulation outputs are associated with ones of said sectors;

a multi-beam antenna having a plurality of substantially non-overlapping narrow beams, each beam having an antenna beam signal associated therewith;

a switch adapted to provide mapping of any of said antenna beam signals to select ones of said modulation outputs, wherein said switch may be controlled to couple combinations of antenna beam signals to modulation outputs including multiple antenna beam signals to a same modulation output and multiple modulation outputs to a same antenna beam signal; and

a controller coupled to said switch and providing signals to said switch to allow signals from each modulation output of the plurality of demodulation inputs to pass to selective pluralities of said antenna beam signals.

42. The system of claim 41, wherein an area of service associated with each sector of said multi-sectored CDMA receiver is defined by said selective pluralities of said antenna beam signals from each modulation output is passed to.