Phased array cellular base station and associated methods for enhanced power efficiency

• US 5,548,813 A
• Filed: 03/24/1994
• Issued: 08/20/1996
• Est. Priority Date: 03/24/1994
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Charas, Philippe M., Dent, Paul W.
• Primary Examiner(s): FAILE, ANDREW I
• Application Number:
  US08/217,301
• Time in Patent Office: 880 Days
• Field of Search: 343/890, 343/700 MS, 342/368, 342/371, 455/33.1, 455/33.2, 455/56.1, 455/54.1, 455/54.2, 455/53.1, 455/33.3, 370/95.3, 370/18
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/0428 radiating a circular polarised wave
• CPC Class Codes: H01Q 9/0435 using two feed points
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A base station includes a radio channel generating circuit for generating a plurality of individual radio channel signals each at a different frequency from one another, and a plurality of individual phased array antennas operatively connected to the radio channel generating circuit so that each individual phased array antenna transmits only one individual radio channel signal at a time. Each of the phased array antennas preferably includes a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern. Each radiating element is readily provided by a stripline, and the substrate is preferably a circuit board. Accordingly, another feature of the base station according to the invention is that power radiated by each phased array antenna can be selectively controlled to reduce possible interference while maintaining communications with respective mobile units that are both near and far from the base station. A switch may be provided between the radio channel generating circuit and the phased array antennas to facilitate cell splitting. Method aspects for operating the base station are also disclosed.

Claims

1. A base station for a cellular communications system including a plurality of coverage areas, said base station comprising:

radio channel generating means for generating a plurality of individual cellular radio channel signals each at a different frequency from one another;

at least four individual phased array antennas, positioned such that at least two of said at least four phased array antennas illuminate at least one common coverage area of the plurality of coverage areas; and

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual cellular radio channel signal.

2. A base station according to Claim 1 wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern.

3. A base station according to claim 2 wherein each radiating element comprises a stripline, and wherein said substrate comprises a circuit board.

4. A base station according to claim 2 further comprising a respective amplifier connected to each radiating element and mounted on said substrate so that each phased array antenna defines an active phased array antenna.

5. A base station according to claim 1 further comprising a tower having a lower portion adjacent ground level and an upper portion on which said phased array antennas are mounted, wherein said radio channel generating means is located adjacent the lower portion of said tower, and wherein said linking means comprises a plurality of interconnecting cables.

6. A base station according to claim 1 further comprising a tower having an upper portion on which said phased array antennas are mounted, and wherein said radio channel generating means is located on said tower.

7. A base station according to claim 1 further comprising a receive antenna positioned adjacent said phased array antennas for receiving from mobile units a plurality of individual radio channel signals each at a different frequency from one another.

8. A base station according to claim 7 wherein said receive antenna comprises a receive phased array antenna including a substrate and a plurality of receive antenna elements mounted thereon in a predetermined pattern.

9. A base station according to claim 8 further comprising:

combining network means mounted on said substrate of said receive antenna and connected to said plurality of receive antenna elements for coherently coupling said plurality of individual radio channel signals received thereby; and

amplifier means mounted on said substrate of said receive antenna and connected to said combining network means for amplifying a signal therefrom.

10. A base station according to claim 1 wherein said radio channel generating means further comprises modulator means for modulating a plurality of radio frequency carriers with respective input signals to thereby generate said plurality of individual radio channel signals.

11. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another;

a plurality of individual phased array antennas; and

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual radio channel signal;

wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern;

said base station further comprising signal quality receiver means for receiving a signal transmitted from a mobile unit relating to signal quality received at the mobile unit, and further comprising antenna power control means connected to said signal quality receiver means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to said signal quality received at the mobile unit.

12. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another;

a plurality of individual phased array antennas; and

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual radio channel signal;

wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern;

said base station further comprising signal strength means for sensing received signal strength from a mobile unit, and further comprising antenna power control means connected to said signal strength means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to the sensed received signal strength.

13. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another;

a plurality of individual phased array antennas;

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual radio channel signal; and

switch means connected between said radio channel generating means and said phased array antennas and movable between first and second positions so that said switch means when in the first position couples together two or more predetermined phased array antennas for increasing radiated antenna power for a respective radio channel signal, and so that said switch means when in the second position decouples the two or more predetermined phased array antennas for increasing radio channel capacity for the base station.

14. A base station for a cellular communications system including a plurality of coverage areas, said base station comprising:

radio channel generating means for generating a plurality of individual cellular radio channel signals each at a different frequency from one another; and

at least four individual phased array antennas positioned such that at least two of said at least four phased array antennas illuminate at least one common coverage area of the plurality of coverage areas and connected to said cellular radio channel generating means so that each individual phased array antenna transmits only one individual radio channel signal.

15. A base station according to claim 14 wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern.

16. A base station according to claim 15 wherein each radiating element comprises a stripline, and wherein said substrate comprises a circuit board.

17. A base station according to claim 15 further comprising a respective amplifier connected to each radiating element and mounted on said substrate so that each phased array antenna defines an active phased array antenna.

18. A base station according to claim 14 further comprising a receive antenna positioned adjacent said phased array antennas for receiving from mobile units a plurality of individual radio channel signals each at a different frequency from one another.

19. A base station according to claim 18 wherein said receive antenna comprises a receive phased array antenna including a substrate and a plurality of receive antenna elements mounted thereon in a predetermined pattern.

20. A base station according to claim 19 further comprising:

combining network means mounted on said substrate of said receive antenna and connected to said plurality of receive antenna elements for coherently coupling said plurality of individual radio channel signals received thereby; and

amplifier means mounted on said substrate of said receive antenna and connected to said combining network means for amplifying a signal therefrom.

21. A base station according to claim 14 wherein said radio channel generating means further comprises modulator means for modulating a plurality of radio frequency carriers with respective input signals to thereby generate said plurality of individual radio channel signals.

22. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another; and

a plurality of individual phased array antennas connected to said radio channel generating means so that each individual phased array antenna transmits only one individual radio channel signal;

wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern;

said base station further comprising signal quality receiver means for receiving a signal transmitted from a mobile unit relating to signal quality received at the mobile unit, and further comprising antenna power control means connected to said signal quality receiver means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to said signal quality received at the mobile unit.

23. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another; and

a plurality of individual phased array antennas connected to said radio channel generating means so that each individual phased array antenna transmits only one individual radio channel signal;

wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern;

said base station further comprising signal strength means for sensing received signal strength from a mobile unit, and further comprising antenna power control means connected to said signal strength means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to the sensed received signal strength.

24. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another;

a plurality of individual phased array antennas connected to said radio channel generating means so that each individual phased array antenna transmits only one individual radio channel signal; and

switch means connected between said radio channel generating means and said phased array antennas and movable between first and second positions so that said switch means when in the first position couples together two or more predetermined phased array antennas for increasing radiated antenna power for a respective radio channel signal, and so that said switch means when in the second position decouples the two or more predetermined phased array antennas for increasing radio channel capacity for the base station.

25. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of radio channel signals;

at least one phased array antenna connected to said radio channel generating means, said at least one phased array antenna comprising a plurality of radiating elements;

signal quality receiver means for receiving a signal transmitted from a mobile unit relating to signal quality received at the mobile unit; and

antenna power control means connected to said signal quality receiver means and said at least one phased array antenna for selectively operating predetermined ones of said radiating elements responsive to said signal quality received at the mobile unit.

26. A base station according to claim 25 wherein said at least one phased array antenna further comprises a substrate on which said plurality of radiating elements are mounted.

27. A base station according to claim 26 wherein each radiating element comprises a stripline, and wherein said substrate comprises a circuit board.

28. A base station according to claim 26 further comprising a respective amplifier connected to each radiating element and mounted on said substrate so that said at least one phased array antenna defines an active phased array antenna.

29. A base station according to claim 28 wherein said antenna power control means comprises a microprocessor operating under stored program control to selectively operate predetermined ones of the amplifiers.

30. A base station for a cellular communications system including a plurality of coverage areas, said base station comprising:

radio channel generating means for generating a plurality of individual cellular radio channel signals each at a different frequency from one another, said radio channel generating means further comprising multiplexing means for time division multiplexing a plurality of input signals for each cellular radio channel signal;

at least four individual phased array antennas positioned such that at least two of said at least four phased array antennas illuminate at least one common coverage area of the plurality of coverage areas; and

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual cellular radio channel signal.

31. A base station according to claim 30 wherein said multiplexing means comprises means for multiplexing each input signal into a respective time slot in a repetitive multiplex frame for a respective radio channel signal.

32. A base station according to claim 30 wherein said multiplexing means comprises means for multiplexing each input signal into predetermined time slot in respective repetitive multiplex frames for a plurality of predetermined radio channel signals.

33. A base station according to claim 32 further comprising a receive antenna positioned adjacent said phased array antennas for receiving from mobile units a plurality of individual radio channel signals each at a different frequency from one another.

34. A base station according to claim 30 wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern.

35. A base station according to claim 34 wherein each radiating element comprises a stripline, and wherein said substrate comprises a circuit board.

36. A base station according to claim 34 further comprising a respective amplifier connected to each radiating element and mounted on said substrate so that each phased array antenna defines an active phased array antenna.

37. A base station according to claim 32 wherein said radio channel generating means further comprises modulator means for modulating a plurality of radio frequency carriers with respective information signals to thereby generate said plurality of individual radio channel signals.

39. A base station according to claim 33 wherein said receive antenna comprises a receive phased array antenna including a substrate and a plurality of receive antenna elements mounted thereon in a predetermined pattern.

38. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another, said radio channel generating means further comprising multiplexing means for time division multiplexing a plurality of input signals for each radio channel signal;

a plurality of individual phased array antennas; and

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual radio channel signal;

wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern;

said base station further comprising signal quality receiver means for receiving a signal transmitted from a mobile unit relating to signal quality received at the mobile unit, and further comprising antenna power control means connected to said signal quality receiver means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to said signal quality received at the mobile unit.

40. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating plurality of individual radio channel signals each at a different frequency from one another, said radio channel generating means further comprising multiplexing means for time division multiplexing a plurality of input signals for each radio channel signal;

a plurality of individual phased array antennas; and

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual radio channel signal;

wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern;

said base station further comprising signal strength means for sensing received signal strength from a mobile unit, and further comprising antenna power control means connected to said signal strength means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to the sensed received signal strength.

41. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of individual radio channel signals each at a different frequency from one another, said radio channel generating means further comprising multiplexing means for time division multiplexing a plurality of input signals for each radio channel signal;

a plurality of individual phased array antennas; and

linking means operatively connecting said radio channel generating means and said phased array antennas so that each individual phased array antenna transmits only one individual radio channel signal;

wherein said multiplexing means comprises means for multiplexing each input signal into predetermined time slot in respective repetitive multiplex frames for a plurality of predetermined radio channel signals;

said base station further comprising switch means connected between said radio channel generating means and said phased array antennas and movable between first and second positions so that said switch means when in the first position couples together two or more predetermined phased array antennas for increasing radiated antenna power for a respective radio channel signal, and so that said switch means when in the second position decouples the two or more predetermined phased array antennas for increasing radio channel capacity for the base station.

42. A base station for a cellular communications system, said base station comprising:

radio channel generating means for generating a plurality of radio channel signals;

a plurality of phased array antennas connected to said radio channel generating means; and

switch means connected between said radio channel generating means and said phased array antennas and movable between first and second positions so that said switch means when in the first position couples together two or more predetermined phased array antennas for increasing radiated antenna power for a respective radio channel signal, and so that said switch means when in the second position decouples the two or more predetermined phased array antennas for increasing radio channel capacity for the base station.

43. A base station according to claim 42 wherein each of said phased array antennas comprises a substrate and a plurality of radiating elements mounted thereon in a predetermined pattern.

44. A base station according to claim 43 further comprising signal quality receiver means for receiving a signal transmitted from a mobile unit relating to signal quality received at the mobile unit, and further comprising antenna power control means connected to said signal quality receiver means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to said signal quality received at the mobile unit.

45. A base station according to claim 43 further comprising signal strength means for sensing received signal strength from a mobile unit, and further comprising antenna power control means connected to said signal strength means and said phased array antennas for selectively operating predetermined ones of said radiating elements in each respective phased array antenna responsive to the sensed received signal strength.

46. A base station according to claim 43 wherein each radiating element comprises a stripline, and wherein said substrate comprises a circuit board.

47. A base station according to claim 46 further comprising a respective amplifier connected to each radiating element and mounted on said substrate so that each phased array antenna defines an active phased array antenna.

48. A base station according to claim 42 wherein said radio channel generating means further comprises modulator means for modulating a plurality of radio frequency carriers with respective input signals to thereby generate said plurality of individual radio channel signals.

49. A method for operating a base station for a cellular radio communications system of the type including a plurality of coverage areas, the base station of the type including at least four individual phased array antennas positioned such that at least two of the at least four phased array antennas illuminate at least one common coverage area of the plurality of coverage areas, said method comprising the steps of:

generating a plurality of individual cellular radio channel signals each at a different frequency from one another; and

operating each individual phased array antenna to transmit only one individual cellular radio channel signal.

50. A method according to claim 49 further comprising receiving from mobile units a plurality of individual radio channel signals each at a different frequency from one another.

51. A method according to claim 49 wherein the step of generating the plurality of individual radio channel signals comprises modulating a plurality of radio frequency carriers with respective input signals.

52. A method according to claim 49 wherein the step of generating a plurality of individual radio channels comprises time division multiplexing a plurality of input signals into predetermined time slots of repetitive multiplex frames.

53. A method for operating a base station for a cellular radio communications system of the type including a plurality of individual phased array antennas, said method comprising the steps of:

generating a plurality of individual radio channel signals each at a different frequency from one another; and

operating each individual phased array antenna to transmit only one individual radio channel signal;

wherein each of the phased array antennas includes a plurality of radiating elements, and further comprising the step of receiving a signal transmitted from a mobile unit relating to signal quality received at the mobile unit, and selectively operating predetermined ones of the radiating elements in each respective phased array antenna responsive to said signal quality received at the mobile unit.

54. A method for operating a base station for a cellular radio communications system of the type including a plurality of individual phased array antennas, said method comprising the steps of:

generating a plurality of individual radio channel signals each at a different frequency from one another;

operating each individual phased array antenna to transmit only one individual radio channel signal; and

coupling together two or more predetermined phased array antennas for increasing radiated antenna power for a respective radio channel signal.

55. A method according to claim 54 further comprising the steps of later decoupling the two or more predetermined phased array antennas, and operating the two or more predetermined phased array antennas with respective different radio frequency channels for increasing radio channel capacity for the base station.

56. A method for operating a base station for a radio cellular radio communications system including at least one phased array antenna comprising a plurality of radiating elements, the method comprising the steps of:

generating a plurality of radio channel signals and transmitting the plurality of radio channel signals from the at least one phased array antenna;

receiving a signal transmitted from a mobile unit relating to signal quality received at the mobile unit; and

selectively operating predetermined ones of the radiating elements responsive to signal quality received at the mobile unit.

57. A method according to claim 56 wherein the at least one phased array antenna further comprises respective amplifiers associated with each of the radiating elements, and wherein the step of selectively operating predetermined ones of the radiating elements comprises selectively controlling power delivered to respective amplifiers.

58. A method for operating a base station for a cellular radio communications system of the type including a plurality of phased array antennas, the method comprising the steps of:

generating a radio channel signal and delivering same to a plurality of predetermined phased array antennas coupled together for increasing radiated antenna power for the radio channel signal; and

later decoupling the plurality of predetermined phased array antennas and operating the predetermined phased array antennas with respective different radio frequency channels for increasing radio channel capacity for the base station.