SYSTEMS AND METHODS FOR DISTRIBUTED ANTENNA SYSTEM REVERSE PATH SUMMATION USING SIGNAL-TO-NOISE RATIO OPTIMIZATION

• US 20110306380A1
• Filed: 06/14/2010
• Published: 12/15/2011
• Est. Priority Date: 06/14/2010
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Zavadsky, Dean, Wala, Philip M., Cannon, Jeffrey J.
• Granted Patent: US 8,509,850 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04B 17/19 Self-testing arrangements
• CPC Class Codes: H04B 7/0842 Weighted combining
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

Systems and methods for distributed antenna system reverse path summation using signal-to-noise ratio optimization are provided. In one embodiment, a method for reverse path summation for a distributed antenna system comprises: normalizing an uplink noise floor for a plurality of remote antenna units of a distributed antenna system, wherein the uplink noise floor is normalized based on a first remote antenna unit having a lowest noise floor of the plurality of remote antenna units; and scaling an uplink output gain of each of the plurality of remote antenna units by a scaling factor, wherein the scaling factor attenuates the uplink output gain based on a composite maximum host peak power for a host unit coupled to the plurality of remote antenna units.

Claims

1. A method for reverse path summation for a distributed antenna system, the method comprising:

normalizing an uplink noise floor for a plurality of remote antenna units of a distributed antenna system, wherein the uplink noise floor is normalized based on a first remote antenna unit having a lowest noise floor of the plurality of remote antenna units; and

scaling an uplink output gain of each of the plurality of remote antenna units by a scaling factor, wherein the scaling factor attenuates the uplink output gain based on a composite maximum host peak power for a host unit coupled to the plurality of remote antenna units.

2. The method of claim 1, wherein the normalizing and scaling are performed at least one antenna unit of the plurality of remote antenna units by attenuating a gain of digital samples generated from wireless RF signals received by the at least one antenna unit, prior to summing of said digital samples with other digital samples received at the at least one remote antenna unit.

3. The method of claim 1, wherein the normalizing and scaling further comprising sending a gain adjustment value to a second remote antenna unit of the plurality of remote antenna units.

4. The method of claim 3, wherein the gain adjustment value instructs the second remote antenna unit to attenuate a gain of digital samples generated from wireless RF signals received by the second remote antenna unit, prior to summing of said digital samples with other digital samples received at the second remote antenna unit

5. The method of claim 1, wherein the scaling factor is based on a difference between a theoretical maximum power of a composite uplink signal from the plurality of remote antenna units and the composite maximum host peak power.

6. The method of claim 1, wherein the plurality of remote antenna units are non-homogenous with respect to performance parameters.

7. The method of claim 1, wherein normalizing the uplink noise floor for the plurality of remote antenna units of the distributed antenna system further comprises:

attenuating an uplink gain for a second remote antenna unit of the plurality of remote antenna units based on a difference between an uplink noise floor for the second remote antenna unit and an uplink noise floor value for the first remote antenna unit.

8. The method of claim 1, further comprising:

calculating an uplink noise floor for each of the plurality of remote antenna units.

9. The method of claim 1, further comprising:

calculating a maximum power contribution value for each of the plurality of remote antenna units; and

summing the maximum power contribution values for each of the plurality of remote antenna units to derive a theoretical composite host power value.

10. The method of claim 9, further comprising:

calculating a total gain adjustment value for a second remote antenna unit of the plurality of remote antenna units based on a function of the maximum power contribution value for the second remote antenna unit and the composite host power value.

11. The method of claim 10, further comprising:

sending the total gain adjustment value for the second remote antenna unit to the second remote antenna unit.

12. The method of claim 11, wherein the total gain adjustment value instructs the second remote antenna unit to attenuate a gain of digital samples generated from wireless RF signals received by the second remote antenna unit, prior to summing of said digital samples with other digital samples received at the second remote antenna unit

13. The method of claim 1, wherein the host unit is coupled to the plurality of remote antenna units by a fiber network.

14. A remote antenna unit for a distributed antenna system, the remote antenna unit comprising:

a first module coupled to at least one antenna, the first module including a converter that digitally samples a wireless RF signal received at the at least one antenna to produce a first stream of digital samples;

a second module coupled to the first module and an incoming signal interface, the second module including a summer that produces a composite signal by summing digital samples from the first stream of digital samples with digital samples based on a second stream of digital samples received via the incoming signal interface;

wherein the first module attenuates a gain of the first stream of digital samples by a factor that normalizes an uplink nose floor for the remote antenna unit based on a noise floor normalization value established for the distributed antenna system;

wherein the first module further attenuates the gain of the first stream of digital samples by a scaling factor based on a composite maximum host peak power for a host unit for the distributed antenna system.

15. The remote antenna unit of claim 14, wherein the first module comprises a register that stores a total gain adjustment value, wherein the first module applies the total gain adjustment value to the first stream of digital sample to attenuate the gain of the first stream of digital samples by the factor that normalizes the uplink noise floor and the scaling factor.

16. The remote antenna unit of claim 15, wherein the first module receives the total gain adjustment value via a communication from the host unit.

17. The remote antenna unit of claim 15, wherein the register further stores a user defined attenuation value.

18. The remote antenna unit of claim 14, wherein the scaling factor is based on a difference between the composite maximum host peak power and a theoretical maximum power of a composite uplink signal at the host unit.

19. The remote antenna unit of claim 14, wherein the second module is coupled to at least one other remote antenna unit over a fiber network via the incoming signal interface, wherein the second stream of digital samples is generated by the at least one other remote antenna unit.

20. A distributed antenna system having optimized reverse path summation, the distributed antenna system comprising:

a host unit;

a plurality of remote antenna units coupled to the host unit;

wherein an uplink noise floor for the plurality of remote antenna units is normalized to a noise floor normalization value based on a remote antenna unit having a lowest noise floor of the plurality of remote antenna units;

wherein an uplink output gain for each of the plurality of remote antenna units is scaled by a scaling factor that is based on a composite maximum host peak power for the host unit.

21. The distributed antenna system of claim 20, wherein a first remote antenna unit of the plurality of remote antenna units comprises:

a first module coupled to at least one antenna, the first module including a converter that digitally samples a wireless RF signal received at the at least one antenna to produce a first stream of digital samples;

a second module coupled to the first module and an incoming signal interface, the second module including a summer that produces a composite signal by summing digital samples from the first stream of digital samples with digital samples based on a second stream of digital samples received via the incoming signal interface;

wherein the first module attenuates a gain of the first stream of digital samples by a factor that normalizes an uplink nose floor for the first remote antenna unit based on the noise floor normalization value;

wherein the first module further attenuates the gain of the first stream of digital samples by the scaling factor.

22. The distributed antenna system of claim 21, wherein the first module comprises a register that stores a total gain adjustment value, wherein the first module applies the total gain adjustment value to the first stream of digital sample to attenuate the gain of the first stream of digital samples by the factor that normalizes the uplink noise floor and the scaling factor.

23. The distributed antenna system of claim 22, wherein the first module receives the total gain adjustment value via a communication from the host unit.

24. The distributed antenna system of claim 21, wherein the scaling factor is based on a difference between the composite maximum host peak power and a theoretical maximum power of a composite uplink signal at the host unit.

25. The distributed antenna system of claim 21, wherein the second module is coupled to at least one other remote antenna unit of the plurality of remote antenna units over a fiber network via the incoming signal interface, wherein the second stream of digital samples is generated by the at least one other remote antenna unit.

26. The distributed antenna system of claim 20, wherein each of the plurality of remote antenna units attenuates a gain of digital samples generated from wireless RF signals received at each respective remote antenna unit, based on the noise floor normalization value and the scaling factor, prior to summing of said digital samples with other digital samples received at each respective remote antenna unit.

27. The distributed antenna system of claim 20, wherein the scaling factor is based on a difference between a theoretical maximum power of a composite uplink signal from the plurality of remote antenna units and the composite maximum host peak power.

28. The distributed antenna system of claim 20, wherein the plurality of remote antenna units are non-homogenous with respect to performance parameters.