TRANSCEIVER ARCHITECTURE AND METHOD FOR WIRELESS BASE-STATIONS

• US 20080014866A1
• Filed: 07/12/2006
• Published: 01/17/2008
• Est. Priority Date: 07/12/2006
• Status: Active Grant

• Current Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Chandrasekaran, Rajiv, Lipowski, Joseph T.
• Granted Patent: US 7,962,174 B2
• Time in Patent Office: Days
• US Class Current: 455/19
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 2200/411 the output amplifying stage of an amplifier comprising two power stages
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system for wireless communications includes a tower structure supporting at least one transmit antenna at an elevated position on the tower structure and base electronics positioned proximate a base of the tower structure. The base electronics are coupled with the transmit antenna and include an initial stage amplifier for amplifying an input signal to provide a low power transmission signal that is provided to the transmit antenna at the elevated position.

A final stage amplifier is positioned proximate the transmit antenna. The final stage amplifier is a high efficiency amplifier for efficiently amplifying the low power transmission signal from the base electronics to provide a high power transmission signal to be transmitted from the transmit antenna.

Claims

1. A system for wireless communications comprising:

a tower structure supporting at least one transmit antenna at an elevated position on the tower structure;

base electronics positioned proximate a base of the tower structure and coupled with the transmit antenna, the base electronics including an initial stage amplifier for amplifying an input signal to provide a low power transmission signal that is provided to the transmit antenna at the elevated position;

a final stage amplifier positioned proximate the transmit antenna, the final stage amplifier being a high efficiency amplifier for efficiently amplifying the low power transmission signal from the base electronics to provide a high power transmission signal to be transmitted from the transmit antenna.

2. The system of claim 1 wherein the initial stage amplifier provides a greater percentage of the amplification of the input signal than the final stage amplifier.

3. The system of claim 2 wherein the initial stage amplifier provides in the range of 25-40 dB of gain.

4. The system of claim 2 wherein the final stage amplifier provides in the range of 10-15 dB of gain.

5. The system of claim 1 wherein the final stage amplifier has an efficiency greater than 30%.

6. The system of claim 1 wherein the final stage amplifier is a high efficiency Dougherty amplifier arrangement.

7. The system of claim 1 wherein the base electronics further include a predistortion circuit for predistorting the input signal to the initial stage amplifier, a predistortion receiver being positioned proximate the final stage amplifier and connected to the predistortion circuit, the predistortion receiver coupled to receive a sample of the high power transmission signal for use by the predistortion circuit.

8. The system of claim 7 wherein the base electronics further include a frequency source for generating at least one LO frequency, the LO frequency combined with the low power transmission signal and directed to the predistortion receiver.

9. A system for wireless communications comprising:

at least one transmit antenna positioned at a first location;

electronics positioned at a second location spaced from the first location and coupled with the transmit antenna, the electronics including an initial stage amplifier for amplifying an input signal to provide a low power transmission signal that is provided to the transmit antenna at the first location;

a final stage amplifier positioned proximate the transmit antenna at the first location, the final stage amplifier providing final amplification for amplifying the low power transmission signal from the second location to provide a high power transmission signal to be transmitted from the transmit antenna.

10. The system of claim 9 wherein the final stage amplifier is a high efficiency amplifier for efficiently amplifying the low power transmission signal.

11. The system of claim 9 wherein the initial stage amplifier provides a greater percentage of the amplification of the input signal than the final stage amplifier.

12. The system of claim 11 wherein the initial stage amplifier provides in the range of 25-40 dB of gain.

13. The system of claim 11 wherein the final stage amplifier provides in the range of 10-15 dB of gain.

14. The system of claim 10 wherein the final stage amplifier has an efficiency greater than 30%.

15. A system for wireless communications comprising:

at least one transmit antenna positioned at a first location;

an initial stage amplifier positioned at a second location spaced from the first location and operable for amplifying an input signal to provide a low power transmission signal that is provided to the first location;

a final stage amplifier positioned proximate the transmit antenna at the first location for amplifying the low power transmission signal to provide a high power transmission signal to be transmitted from the transmit antenna;

a predistortion circuit at the second location for predistorting the input signal to the initial stage amplifier;

a predistortion receiver positioned proximate the final stage amplifier and connected to the predistortion circuit, the predistortion receiver coupled to receive a sample of the high power transmission signal and process the high power transmission signal for provision to the predistortion circuit at second location.

16. The system of claim 15 wherein the first location is an elevated position on a support structure and the second location is at a base of the support structure.

17. The system of claim 15 further including a frequency source at the second location for generating at least one LO frequency, the LO frequency combined with the low power transmission signal and directed to the predistortion receiver at the first location.

18. The system of claim 15 wherein the predistortion receiver combines the sample of the high power transmission signal and the LO frequency to form an IF signal that is used by the predistortion circuit.

19. The system of claim 15 further including:

at least one receive antenna at the first location to capture a receive signal;

a frequency source at the second location for generating at least one LO frequency, the LO frequency combined with the low power transmission signal and directed to the first location;

a filter at the first location to separate the LO frequency and the low power transmission signal.

20. The system of claim 19 including a plurality of receive antennas at the first location and wherein the frequency source is operable for generating a plurality of LO frequencies for combining with a plurality of receive signals to form a plurality of IF signals.

21. The system of claim 20 wherein the plurality of IF signals have different IF frequencies and further including a combiner circuit to combine the different IF frequencies for transmission to the second location.

22. The system of claim 20 wherein the plurality of IF signals have the same IF frequency and further including plurality of receive cables for transmission of the IF signals to the second location.

23. The system of claim 18 wherein the IF signal has a frequency sufficiently separated from the frequency of the high power transmission signal in order to reduce interference.

24. The system of claim 15 wherein the initial stage amplifier provides a greater percentage of the amplification of the input signal than the final stage amplifier.

25. A system for wireless communications comprising:

at least one transmit antenna and at least one receive antenna positioned at a first location;

an initial stage amplifier positioned at a second location spaced from the first location and operable for amplifying an input signal to provide a low power transmission signal that is provided to the first location;

a final stage amplifier positioned proximate the transmit antenna at the first location for amplifying the low power transmission signal to provide a high power transmission signal to be transmitted from the transmit antenna;

a frequency source at the second location for generating a plurality of LO frequencies;

a combiner for combining the LO frequencies with the low power transmission signal to be directed to first location.

a filter to separate the LO frequencies and the low power transmission signal so the transmission signal can be further amplified and the LO frequencies may be combined with a receive signal of a receive antenna to form an IF signal.

26. The system of claim 25 further comprising a predistortion circuit at the second location for predistorting the input signal to the initial stage amplifier.

27. The system of claim 26 further comprising a predistortion receiver positioned proximate the final stage amplifier and connected to the predistortion circuit, the predistortion receiver operable to use an LO frequency and a sample of the high power transmission signal and generate an IF signal for the predistortion at the second location.

28. The system of claim 25 wherein the first location is an elevated position on a support structure and the second location is at a base of the support structure.

29. A method for providing wireless communications comprising:

positioning at least one transmit antenna at a first location;

amplifying an input signal with an initial stage amplifier to provide a low power transmission signal at a second location and forwarding the low power transmission signal to the transmit antenna;

amplifying, at the first location, the low power transmission signal with a final stage amplifier, the final stage amplifier being a high efficiency amplifier for efficiently amplifying the low power transmission signal to provide a high power transmission signal to be transmitted from the transmit antenna.

30. The system of claim 29 wherein the first location is an elevated position on a support structure and the second location is at a base of the support structure.

31. The method of claim 29 further comprising providing a greater percentage of the amplification of the input signal with the initial stage amplifier than with the final stage amplifier.

32. The method of claim 31 wherein the initial stage amplifier provides in the range of 25-40 dB of gain.

33. The method of claim 31 wherein the final stage amplifier provides in the range of 10-15 dB of gain.

34. The method of claim 29 wherein the final stage amplifier has an efficiency greater than 30%.

35. The method of claim 29 further comprising predistorting the input signal with a predistortion circuit at the second location and, at the first location, coupling off a sample of the high power transmission signal and providing it back to the predistortion circuit at the second location.

36. The method of claim 29 further comprising generating at least one LO frequency at the second location and combining the LO frequency with the low power transmission signal and transmitting the combined signal to the first location.

37. The method of claim 36 further comprising combining the sample of the high power transmission signal with an LO frequency to form an IF signal that is used by the predistortion circuit.

38. The method of claim 36 further comprising generating the LO frequency at the second location, combining the LO frequency with the low power transmission signal for transmission of the combined signal to the first location and filtering the combined signal to separate the LO frequency and the low power transmission signal.

39. The method of claim 36 further comprising positioning at least one receive antenna at the first location to capture a receive signal, and combining the LO frequency with the receive signal to form an IF signal.

40. The method of claim 39 further comprising positioning a plurality of receive antennas and generating a plurality of LO frequencies for combining with a plurality of receive signals to form a plurality of IF signals.

41. The method of claim 40 wherein the plurality of IF signals have different IF frequencies and further including combining the different IF frequencies for transmission to the second location.

42. The method of claim 40 wherein the plurality of IF signals have the same IF frequency and further including using a plurality of receive cables to transmit the IF signals to the second location.

43. The method of claim 39 wherein the IF signal has a frequency sufficiently separated from the frequency of the high power transmission signal in order to reduce interference.