Cellular communications systems

• US 6,640,111 B1
• Filed: 09/02/1999
• Issued: 10/28/2003
• Est. Priority Date: 03/03/1997
• Status: Expired due to Fees

• Current Assignee: Celletra Ltd. (Unity Wireless Corp.)
• Original Assignee: Celletra Ltd. (Unity Wireless Corp.)
• Inventors: Shapira, Joseph
• Primary Examiner(s): Le, Thanh Cong
• Assistant Examiner(s): Nguyen, Thuan T.
• Application Number:
  US09/389,053
• Time in Patent Office: 1,517 Days
• Field of Search: 455/10, 455/25, 455/561, 455/422, 455/424, 455/562, 455/14, 455/523
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/2676 Optically controlled phased array
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/0848 Joint weighting
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04W 88/085 Access point devices with remote components
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A novel base station for cellular wireless communications based on a modular structure is provided. The modular cellular wireless communication base station includes a plurality of active radiator modules (ARM'"'"'s) located at a desired antenna location, a beam forming network controlling relative amplitudes and phases of each of the modules and an RF front end. Each module (100) includes at least one antenna (ant) for transmitting and receiving, a transmitter having a power amplifier, and receiver.

Claims

1. A modular cellular wireless communication base station comprising a plurality of active radiator modules (ARM'"'"'s) located at a desired antenna location, each module comprising:

at least one subscriber antenna for transmitting and receiving, a transmitter comprising a power amplifier, and a receiver;

a beam forming network controlling relative amplitudes and phases of each of said modules; and

an RF front end transmitting over a low power link with said plurality of active radiator modules via said beam forming network and receiving over a lower power link via a low noise amplifier.

2. A modular cellular wireless communication base station according to claim 1 and wherein said RF front end is located remote from said plurality of modules.

3. A modular cellular wireless communication base station according to claim 1 and wherein each module is self-enclosed.

4. A modular cellular wireless communication base station according to claim 1 and wherein at least one of said active radiator modules comprises separate transmit and receive antenna elements.

5. A modular cellular wireless communication base station according to claim 4 wherein said transmit and receive antenna elements are isolated from each other by approximately 20 dB.

6. A modular cellular wireless communication base station according to claim 1 and wherein said beam forming network is located adjacent said plurality of active radiator modules, one for transmit and one for receive.

7. A modular cellular wireless communication base station according to claim 1 and comprising a CATV up/down converter module.

8. A modular cellular wireless communication base station according to claim 7 wherein said CATV up/down converter module comprises a coaxial cable connected to a CATV network, said cable carrying a CATV forward link and reverse link.

9. A modular cellular wireless communication base station according to claim 8 comprising a CATV diplexer that separates transmit and receive signals.

10. A modular cellular wireless communication base station according to claim 7 and wherein said converter module comprises a mixer, a phased locked oscillator and a band pass filter, to eliminate image and low frequencies.

11. A modular cellular wireless communication base station according to claim 1 wherein said RF front end communicates with said beam forming network via a fiber optic link.

12. A modular cellular wireless communication base station according to claim 11 comprising at least two separate fibers for separately carrying transmitter and receiver signals.

13. A modular cellular wireless communication base station according to claim 11 comprising one fiber that carries both transmitter and receiver signals, and a splitter and a filter provided to split and filter said signals.

14. A modular cellular wireless communication base station according to claim 1 and wherein said transmitter amplifier comprises a first stage comprising a monolithic silicon gain stage and a second stage comprising a hybrid packaged power amplifier.

15. A modular cellular wireless communication base station according to claim 1 and comprising a transmitter filter that reduces transmitter wide band noise in a receiver band.

16. A modular cellular wireless communication base station according to claim 1 and comprising a transmitter filter that reduces spurious signals that interfere with a receiver channel of a cell.

17. A modular cellular wireless communication base station according to claim 1 and comprising a receiver amplifier and a receiver filter, wherein said receiver filter reduces a transmitter signal to a level wherein interfering intermod products are not generated in a receive chain, and said receiver amplifier is not desensitized by saturation.

18. A modular cellular wireless communication base station according to claim 1 and comprising a receiver filter that reduces interfering signals from sources external to said wireless communication base station.

19. A modular cellular wireless communication base station according to claim 1 and wherein said plurality of active radiator modules are stacked to form an active antenna having desired gain and beam shape determined by said beam forming network.

20. A modular cellular wireless communication base station according to claim 19, wherein said active radiator modules are stacked in a configuration selected from the group consisting of a vertical array, a planar array and a circular array.

21. A modular cellular wireless communication base station according to claim 1 wherein said at least one of said active radiator modules comprises a transmit antenna and first and second receive antenna elements.

22. A modular cellular wireless communication base station according to claim 21 wherein said transmit antenna is a vertically polarized antenna and wherein said first receive antenna is polarized at +45°

and said second receive antenna is polarized at −

45°

.

25. A modular cellular wireless communication base station according to claim 21 further comprising a transmit amplifier coupled to said transmit antenna and a receive amplifier coupled to each of said first and second receive antenna elements.

26. A modular cellular wireless communication base station according to claim 1 wherein said at least one of said active radiator modules comprises a first and second transmit antennas and a receive antenna element.

27. A modular cellular wireless communication base station according to claim 26 wherein said receive antenna is a vertically polarized antenna and wherein said first transmit antenna is polarized at +45°

and said second transmit antenna is polarized at −

45°

.

28. A modular cellular wireless communication base station according to claim 26 and further comprising a transmit amplifier coupled to each of said transmit antennas and a receive amplifier coupled to said receive antenna element.

29. A modular cellular wireless communication base station according to claim 1 and wherein said at least one antenna comprises an intelligent antenna.

30. A modular cellular wireless communication base station according to claim 29 wherein said intelligent antenna comprises multiplex trunking.

23. A modular cellular communication base station comprising:

a plurality of active radiator modules (ARM'"'"'s) located at a desired antenna location, each module comprising at least one antenna for transmitting and receiving, a transmitter comprising a power amplifier, and a receiver;

a beam forming network controlling relative amplitudes and phases of each of said modules; and

an RF front end transmitting over a low power link with said plurality of active radiator modules via said beam forming network and receiving over a lower power link via a low noise amplifier;

wherein at least one of said active radiator modules comprising a transmit antenna and first and second receive antenna elements; and

wherein said plurality of active radiator modules are configured for a width less than 0.7 wavelengths, for forming a multitude of beams in a horizontal plane.

24. A modular cellular communication base station comprising:

a plurality of active radiator modules (ARM'"'"'s) located at a desired antenna location, each module comprising at least one antenna for transmitting and receiving, a transmitter comprising a power amplifier, and a receiver;

a beam forming network controlling relative amplitudes and phases of each of said modules; and

an RF front end transmitting over a low power link with said plurality of active radiator modules via said beam forming network and receiving over a lower power link via a low noise amplifier;

wherein at least one of said active radiator modules comprising a transmit antenna and first and second receive antenna elements; and

wherein said plurality of active radiator modules are configured for a height less than 1 wavelength, for forming a broad side radiation from a vertically stacked column of said plurality of active radiator modules.

31. A modular cellular communication base station comprising:

a plurality of active radiator modules (ARM'"'"'s) located at a desired antenna location, each module comprising at least one antenna for transmitting and receiving, a transmitter comprising a power amplifier, and a receiver;

a beam forming network controlling relative amplitudes and phases of each of said modules; and

an RF front end transmitting over a low power link with said plurality of active radiator modules via said beam forming network and receiving over a lower power link via a low noise amplifier; and

wherein at least one of said receiver and said transmitter outputs to a digital sample bus that is sampled by a communications channel card.

32. A modular cellular wireless communication base station according to claim 31 wherein an output of said at least one of said receiver and said transmitter is transformed by a transform circuit and is connected to at least one antenna input in a CDMA base station.

33. A modular cellular wireless communication base station according to claim 32 wherein said transform circuit comprises a Butler matrix.

34. A modular cellular wireless communication base station according to claim 31 wherein a beam of said transmitter is shaped to follow a coverage requirement.

35. A modular cellular wireless communication base station according to claim 31 wherein a beam of said transmitter is enhanced by transmission diversity.

36. A modular wireless communication base station comprising:

a plurality of active radiator modules located at a desired antenna location, each of said active radiator modules comprising at least one transmit antenna element, a transmit amplifier, at least one receive antenna element, and a receive amplifier; and

a beamforming network coupled to said active radiator modules;

wherein said beamforming network transforms transmit signals into a form suitable for producing a radiation pattern by said at least one transmit antenna element of said active radiator modules; and

wherein said beamforming network transforms receive signals generated by said at least one receive antenna element of said active radiator module, in response to receiving a radiation pattern, into a form suitable for processing.

37. The modular wireless communication base station of claim 36, wherein said active radiator modules comprise filters to provide isolation between said at least one transmit antenna element and said at least one receive antenna element.

38. The modular wireless communication base station of claim 37, wherein said filters comprise a transmit filter configured to perform at least one of reducing transmitter wideband noise and reducing spurious interference signals.

39. The modular wireless communication base station of claim 38, wherein said filters comprises a receive filter configured to perform at least one of reducing interference signals and intermodulation signals.

40. The modular wireless communication base station of claim 39, wherein said transmit amplifier comprises a low power amplifier and said receive amplifier comprises a low noise amplifier.

41. The modular wireless communication base station of claim 40, further including a plurality of transceivers configured to generate and process said transmit and receive signals, said transceivers being coupled to said beamforming network and remotely situated from said active radiator modules.

42. The modular wireless communication base station of claim 41, wherein said transceivers are coupled to said beamforming network via a fiber-optic link comprising at least one optical fiber configured to support said transmit signals and at least one optical fiber configured to support said receive signals.

43. The modular wireless communication base station of claim 41, wherein said transceivers are coupled to said beamforming network via a fiber-optic link comprising one optical fiber configured to support both said transmit and receive signals, a splitter to separate said transmit and receive signals, and a filter to isolate said transmit and receive signals.

44. The modular wireless communication base station of claim 41, wherein said beamforming network comprises a transmit portion for transforming said transmit signals and a receive portion for transforming said receive signals.

45. The modular wireless communication base station of claim 41, wherein said active radiator modules are arranged in an array configuration comprising at least one of a vertical array, a planar array, a horizontal array, and a circular array.

46. The modular wireless communication base station of claim 45, wherein said array configuration of said active radiator modules comprises an intelligent antenna capable of forming a plurality of radiated beams and wherein said beamforming network implements at least one of phase control and amplitude control to determine attributes of said radiated beams.

47. The modular wireless communication base station of claim 46, wherein said transceivers communicate with said beamforming network via a multiplexed trunking scheme.

48. The modular wireless communication base station of claim 47, wherein a delay is introduced in at least one of said beamforming network and said active radiator modules to provide transmission diversity.

49. The modular wireless communication base station of claim 48, wherein said delay comprises a duration greater than a CDMA chip interval.

50. The modular wireless communication base station of claim 47, wherein said active radiator modules are configured to provide at least one of transmit polarization diversity and receive polarization diversity.

51. The modular wireless communication base station of claim 50, wherein said active radiator modules includes a vertically-polarized transmit antenna element, a first slant-polarized receive antenna element at +45°

, and a second slant-polarized receive antenna element at −

45°

to achieve said receive polarization diversity.

52. The modular wireless communication base station of claim 50, wherein said active radiator modules includes a vertically-polarized receive antenna element, a first slant-polarized transmit antenna element at +45°

, and a second slant-polarized transmit antenna element at −

45°

to achieve said transmit polarization diversity.

53. The modular wireless communication base station of claim 45, further including,

a CATV up/down converter module coupled to said active radiator modules and comprising a mixer, a phase-locked oscillator, a band pass filter,

a cable coupled to a CATV network and configured to support CATV forward and reverse link signals, and

a CATV diplexer coupled to said CATV up/down converter module and said cable and configured to separate said CATV forward and reverse link signals.