DISTRIBUTED ANTENNA SYSTEM ARCHITECTURES

• US 20120329523A1
• Filed: 06/13/2012
• Published: 12/27/2012
• Est. Priority Date: 06/13/2011
• Status: Active Grant

• Current Assignee: Outdoor Wireless Networks LLC (CommScope Holding Company, Inc.)
• Original Assignee: LGC Wireless LLC (TE Connectivity Limited)
• Inventors: Fischer, Larry G., Stewart, Kenneth Anderson
• Granted Patent: US 9,748,906 B2
• Time in Patent Office: Days
• US Class Current: 455/562.1
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 5/1423 for simultaneous baseband signals
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

One embodiment is directed to a distributed antenna system comprising a host unit and at least one remote antenna unit that is communicatively coupled to the host unit. The remote antenna unit is configured to perform self-interference suppression processing in an upstream signal path using, as an input thereto, a feedback signal derived from the downstream radio frequency signal radiated from the antenna. Other embodiments are disclosed.

Claims

1. A distributed antenna system comprising:

a host unit; and

at least one remote antenna unit that is communicatively coupled to the host unit;

wherein the host unit is configured to communicate a downstream transport signal from the host unit to the remote antenna unit;

wherein the remote antenna unit to which the downstream transport signal is communicated uses the downstream transport signal to generate a downstream radio frequency signal for radiation from an antenna associated with the remote antenna unit;

wherein the remote antenna unit is configured to communicate an upstream transport signal from the remote antenna unit to the host unit, wherein the upstream transport signal is generated from a received upstream radio frequency signal received at the remote antenna unit; and

wherein the remote antenna unit is configured to perform self-interference suppression processing in an upstream signal path using, as an input thereto, a feedback signal derived from the downstream radio frequency signal radiated from the antenna.

2. The distributed antenna system of claim 1, wherein the remote antenna system is configured to receive the received upstream radio frequency signal using the same antenna used to radiate the downstream radio frequency signal.

3. The distributed antenna system of claim 2, wherein the remote antenna system further comprises a duplexer coupled to the antenna.

4. The distributed antenna system of claim 3, wherein the duplexer comprises a low-power duplexer.

5. The distributed antenna system of claim 4, wherein the low-power duplexer comprises a mobile handset duplexer.

6. The distributed antenna system of claim 1, wherein the remote antenna system is configured to radiate the downstream radio frequency signal from a first antenna and wherein the remote antenna system is configured to receive the received upstream radio frequency signal using a second antenna.

7. The distributed antenna system of claim 6, wherein the remote antenna system does not use a duplexer.

8. The distributed antenna system of claim 1, wherein the downstream transport signal comprises a digitized version of an original downstream radio frequency signal received at the host unit and wherein the upstream transport signal comprises a digitized version of the received upstream radio frequency signal received at the remote antenna unit.

9. The distributed antenna system of claim 1, wherein at least one of the downstream transport signal and the upstream transport signal comprises digital baseband data.

10. The distributed antenna system of claim 9, wherein the digital baseband data comprises at least of one OBSAI digital baseband data or CPRI digital baseband data.

11. The distributed antenna system of claim 1, wherein the downstream transport signal comprises an analog version of an original downstream radio frequency signal received at the host unit and wherein the upstream transport signal comprises an analog version of the received upstream radio frequency signal received at the remote antenna unit.

12. The distributed antenna system of claim 1, wherein a plurality of antennas is coupled to the remote antenna unit.

13. The distributed antenna system of claim 1, wherein the distributed antenna system is configured to distribute MIMO signals.

14. The distributed antenna system of claim 1, wherein the remote antenna unit comprises a feedback path and a switch to selectively couple either the downstream radio frequency signal or an external radio frequency signal to an input of the feedback path.

15. A remote antenna unit for use in a distributed antenna system, the remote antenna unit comprising:

a transport interface to communicatively couple the remote antenna unit to a host unit included in the distributed antenna system and to receive a downstream transport signal from the host unit;

a processing unit coupled to the transport interface;

at least one downstream signal branch; and

at least one upstream signal branch;

wherein the processing unit and downstream signal branch are configured to use the downstream transport signal to generate a downstream radio frequency signal for radiation from an antenna associated with the remote antenna unit;

wherein the transport interface is configured to communicate an upstream transport signal from the remote antenna unit to the host unit, wherein the processing unit and the upstream signal branch are configured to generate an upstream signal from a received upstream radio frequency signal received at the remote antenna unit, wherein the transport interface uses the upstream signal to generate the upstream transport signal; and

wherein the processing unit is configured to perform self-interference suppression processing on the upstream signal using, as an input thereto, a feedback signal derived from the downstream radio frequency signal radiated from the antenna.

16. The remote antenna unit of claim 15, wherein the remote antenna system is configured to receive the received upstream radio frequency signal using the same antenna used to radiate the downstream radio frequency signal.

17. The remote antenna unit of claim 16, wherein the remote antenna system further comprises a duplexer coupled to the antenna.

18. The remote antenna unit of claim 17, wherein the duplexer comprises a low-power duplexer.

19. The remote antenna unit of claim 18, wherein the low-power duplexer comprises a mobile handset duplexer.

20. The remote antenna unit of claim 15, wherein the remote antenna system is configured to radiate the downstream radio frequency signal from a first antenna and wherein the remote antenna system is configured to receive the received upstream radio frequency signal using a second antenna.

21. The remote antenna unit of claim 20, wherein the remote antenna system does not use a duplexer.

22. The remote antenna unit of claim 15, wherein the downstream transport signal comprises a digitized version of an original downstream radio frequency signal received at the host unit and wherein the upstream transport signal comprises a digitized version of the received upstream radio frequency signal received at the remote antenna unit.

23. The remote antenna unit of claim 15, wherein at least one of the downstream transport signal and the upstream transport signal comprises digital baseband data.

24. The remote antenna unit of claim 23, wherein the digital baseband data comprises at least of one OBSAI digital baseband data or CPRI digital baseband data.

25. The remote antenna unit of claim 15, wherein the downstream transport signal comprises an analog version of an original downstream radio frequency signal received at the host unit and wherein the upstream transport signal comprises an analog version of the received upstream radio frequency signal received at the remote antenna unit.

26. The remote antenna unit of claim 15, wherein a plurality of antennas is coupled to the remote antenna unit.

27. The remote antenna unit of claim 15, wherein the remote antenna unit is configured to distribute MIMO signals.

28. The remote antenna unit of claim 15, wherein the remote antenna unit comprises a feedback path and a switch to selectively couple either the downstream radio frequency signal or an external radio frequency signal to an input of the feedback path.

29. A remote antenna unit for use in a distributed antenna system, the remote antenna unit comprising:

a transport interface to communicatively couple the remote antenna unit to a host unit included in the distributed antenna system and to receive a downstream transport signal from the host unit;

a processing unit coupled to the transport interface;

at least one downstream signal branch; and

at least one upstream signal branch;

wherein the processing unit and downstream signal branch are configured to use the downstream transport signal to generate a downstream radio frequency signal for radiation from an antenna associated with the remote antenna unit;

wherein the transport interface is configured to communicate an upstream transport signal from the remote antenna unit to the host unit, wherein the processing unit and the upstream signal branch are configured to generate an upstream signal from a received upstream radio frequency signal received at the remote antenna unit, wherein the transport interface uses the upstream signal to generate the upstream transport signal; and

wherein the processing unit is configured to pre-distort an input signal to the downstream signal branch for non-linearities in the downstream signal branch using a feedback signal derived from the downstream radio frequency signal radiated from the antenna.

30. The remote antenna unit of claim 29, wherein the remote antenna system further comprises a duplexer coupled to the antenna.

31. The remote antenna unit of claim 30, wherein the duplexer comprises a high-wherein the remote antenna unit comprises a feedback path and a switch to selectively couple either the downstream radio frequency signal or an external radio frequency signal to an input of the feedback path.

32. The remote antenna unit of claim 29, wherein the remote antenna unit comprises a feedback path and a switch to selectively couple either the downstream radio frequency signal or an external radio frequency signal to an input of the feedback path.