Small signal threshold and proportional gain distributed digital communications

• US 7,103,377 B2
• Filed: 04/16/2003
• Issued: 09/05/2006
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Procomm International Pte. Ltd. (Transpacific IP Group Limited)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Bauman, Donald R., Wala, Philip M., Toms, Jerry Edward
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US10/414,907
• Publication Number:
  US 20040106387A1
• Time in Patent Office: 1,238 Days
• Field of Search: 455/522, 455/561, 455/562.1, 455/127.2, 455/127.3, 455/232.1, 455/234.1, 455/245.2, 455/249.1, 455/250.1, 375/345
• US Class Current: 455/522
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

A method for signal gain adjustment in a multi-port, digital distributed antenna system uses a sorter to sort received signals in ascending order according to their signal levels. A threshold comparator generates a dynamic range fair threshold that is updated as any remaining system dynamic range is distributed amongst the remaining signals. Any received signal that is less than or equal to the threshold is attenuated with a unity gain factor. A signal that is greater than the threshold is attenuated with a gain factor that is inversely proportional to the signal level.

Claims

1. A method for gain distribution in a system comprising a plurality of distributed antennas and a total system dynamic range, the method comprising:

sensing a signal level at each of the plurality of distributed antennas;

comparing at least one of the plurality of signal levels with a dynamic range fair share threshold; and

attenuating each of the at least one of the compared signal levels that is greater than the dynamic range fair share threshold with a gain factor that is determined in response to a remaining portion of the total system dynamic range after attenuation of other signal levels of the plurality of signal levels.

2. The method of claim 1 wherein the dynamic range fair share threshold is initially determined by an inverse of a quantity of the plurality of distributed antennas.

3. The method of claim 1 and further including:

sorting the sensed signal levels in an ascending order prior to comparing; and

updating the total system dynamic range, after attenuation of each signal level, by allocating unused total system dynamic range to subsequently attenuated signal levels.

4. The method of claim 1 and further including attenuating with unity gain signal levels that are less, than or equal to the dynamic range fair share threshold.

5. The method of claim 1 wherein if the signal level is greater than the dynamic range fair share threshold, the gain factor applied to a first signal level is inversely proportional to the first signal level.

6. The method of claim 5 wherein the gain factor is substantially equal to K/x_j where K is an inverse of a quantity of the plurality of distributed antennas and x_j is the first signal level.

7. A method for gain distribution in a distributed antenna system having a total dynamic range, the method comprising:

sorting a plurality of signal levels from the distributed antenna system;

comparing each of the sorted signal levels with a dynamic range fair share threshold;

if a first signal level is less than or equal to the dynamic range fair share threshold, applying a unity gain factor to the first signal level and dividing remaining total dynamic range between remaining signal levels of the plurality of signal levels; and

if the first signal level is greater than the dynamic range fair share threshold, applying a gain factor that is inversely proportional to the first signal level.

8. The method of claim 7 wherein the gain factor that is substantially equal to the inverse of the first signal level is equal to a quantity of distributed antennas in the distributed antenna system divided by the first signal level.

9. The method of claim 7 wherein the plurality of signal levels are sorted in ascending order.

10. A method for gain distribution in a distributed antenna system having a system dynamic range, the method comprising:

sorting, in ascending order, a plurality of signal levels from the distributed antenna system;

comparing a first signal level of the plurality of sorted signal levels with a dynamic range fair share threshold;

if the first signal level is less than or equal to the dynamic range fair share threshold, applying a unity gain factor to the first signal level;

if the unity gain factor has been applied to the first signal level, updating the dynamic range fair share threshold to allocate remaining system dynamic range between remaining signal levels; and

if the first signal level is greater than the dynamic range fair share threshold, applying a first gain factor that is substantially equal to the dynamic range fair share threshold divided by the first signal level.

11. The method of claim 10 and further including applying a second gain factor to a second signal level if the second signal level is greater than the dynamic range fair share threshold, the second gain factor being substantially equal to the dynamic range fair share threshold divided by the second signal level.

12. The method of claim 10 and further including if the unity gain factor has been applied to the first signal level, updating the system dynamic range by decreasing the remaining system dynamic range by the first signal level to which the gain factor has been applied.

13. A method for gain distribution in a distributed antenna system having a system dynamic range, the method comprising:

sensing a signal level for each of a plurality of received signals from the distributed antenna system;

sorting, in ascending order, the plurality of signal levels;

comparing a first signal level of the plurality of sorted signal levels with a dynamic range fair share threshold;

if the first signal level is less than or equal to the dynamic range fair share threshold, applying a unity gain factor to the first signal level;

if the unity gain factor has been applied to the first signal level, updating the dynamic range fair share threshold to allocate remaining system dynamic range between remaining signal levels; and

if the first signal level is greater than the dynamic range fair share threshold, applying a first gain factor that is substantially equal to the dynamic range fair share threshold divided by the first signal level.

14. A distributed antenna system having gain distribution and a total dynamic range, the system comprising:

a plurality of distributed antennas that receive signals each having a signal level;

a sorter that sorts the received signals according to each signal level;

threshold comparator coupled to the sorter, that generates comparison results in response to a comparison between a sorted signal and a dynamic range fair share threshold that is updated with a remaining system dynamic range;

a remaining dynamic range calculator that generates the remaining system dynamic range by decreasing the total dynamic range by each attenuated signal level; and

a gain calculator, coupled to the sorter, the threshold comparator, and the remaining dynamic range calculator, that progressively generates gain factors in response to the comparison results.

15. The distributed antenna system of claim 14 wherein the distributed antennas are coupled through distributed summers over a communication medium.

16. The distributed antenna system of claim 15 wherein the communication medium is an optical medium.

17. The distributed antenna system of claim 14 wherein the sorter sorts the received signals in ascending order in response to each'"'"'signal level.

18. A distributed antenna system having gain distribution and a total dynamic range, the system comprising:

a plurality of distributed antennas that receive signals each having a signal level;

a signal level sampling function that senses each signal level;

a sorter that sorts the received signals in ascending order according to each signal level;

a threshold comparator, coupled to the sorter, that generates a comparison result in response to a comparison between a sorted signal and a dynamic range fair share threshold that is updated with a remaining system dynamic range;

a remaining dynamic range calculator that generates the remaining system dynamic range by decreasing the total dynamic range by each attenuated signal level;

a gain calculator, coupled to the sorter, the threshold comparator, and the remaining dynamic range calculator, that progressively generates a gain factor for each received signal in ascending order in response to each comparison result; and

a plurality of attenuators, each attenuator coupled to a received signal, for attenuating each received signal in response-to its gain factor.

19. The system of claim 18 wherein the gain calculator generates a gain factor of unity for a received signal if its signal level is less than or equal to the dynamic range fair share threshold.

20. The system of claim 18 wherein the gain factors are generated in discrete increments.

21. A distributed antenna system having gain distribution and a total dynamic range, the system comprising:

a plurality of distributed antennas that receive analog signals each having a signal level represented in a digital form;

an analog to digital converter that converts the analog signals to digital signals;

a sorter that sorts the digital signals according to each signal level;

a threshold comparator, coupled to the sorter, that generates a comparison result in response to a comparison between a sorted signal and a dynamic range fair share threshold that is updated with a remaining system dynamic range;

a remaining dynamic range calculator that generates the remaining system dynamic range by decreasing the total dynamic range by each attenuated signal level; and

a gain calculator, coupled to the sorter, the threshold comparator, and the remaining dynamic range calculator, that progressively generates gain factors in response to the comparison results.

22. A method for gain distribution in a distributed antenna system having a system dynamic range, the distributed antenna system being coupled by an optical network, the method comprising:

receiving a plurality of analog signals;

converting each analog signal to a digital signal having a signal level expressed in a digital format;

sorting, in ascending order, the plurality of digital signals according to their signal levels;

comparing a first digital signal level of the plurality of digital signals with a dynamic range fair share threshold;

if the first digital signal level is less than or equal to the dynamic range fair share threshold, applying a unity gain factor to the first digital signal level;

if the unity gain factor has been applied to the first digital signal level, updating the dynamic range fair share threshold to allocate remaining system dynamic range between remaining digital signals; and

if the first digital signal level is greater than the dynamic range fair share threshold, applying a first gain factor that is substantially equal to the dynamic range fair share threshold divided by the first digital signal level.