SYSTEM-WIDE UPLINK BAND GAIN CONTROL IN A DISTRIBUTED ANTENNA SYSTEM (DAS), BASED ON PER-BAND GAIN CONTROL OF REMOTE UPLINK PATHS IN REMOTE UNITS

• US 20160095068A1
• Filed: 09/25/2014
• Published: 03/31/2016
• Est. Priority Date: 09/25/2014
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications Wireless Ltd. (Corning Incorporated)
• Inventors: Henia, Yoni
• Granted Patent: US 9,420,542 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04B 17/13 of power amplifiers, e.g. gain or non-linearity
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

System-wide uplink band gain control in a distributed antenna system (DAS) based on per-band gain control of remote uplink paths in remote units is disclosed. In one embodiment, for each uplink band in the DAS, a gain control system receives remote uplink band power measurements for each remote uplink path for the uplink band. Based on these power measurements, the gain control system determines if the uplink gain of all of the remote uplink paths of the plurality of uplink paths of the uplink band should be adjusted. If the uplink gain of the remote uplink paths of the uplink band should be adjusted, the gain control system directs a remote uplink gain control circuit for each remote uplink path of the uplink band to adjust the uplink gain by a defined remote uplink band gain level.

Claims

1. A gain control system for providing system-wide uplink band gain control in a distributed antenna system (DAS), based on per-band gain control of remote uplink paths in remote units, comprising:

a plurality of remote units, each comprising;

a plurality of remote uplink band power measurement circuits each coupled to a remote uplink path among a plurality of remote uplink paths each carrying at least one uplink band communications signal in a remote unit, each remote uplink band power measurement circuit among the plurality of remote uplink band power measurement circuits configured to;

measure a remote uplink band power of an uplink band communications signal in the remote uplink path in the remote unit; and

provide a remote uplink band power measurement indicative of the measured remote uplink band power of the uplink band communications signal in the remote uplink path; and

a central controller configured to, for each uplink band in the DAS;

(i) receive the remote uplink band power measurement for each remote uplink path for the uplink band;

(ii) determine if an uplink gain of the remote uplink paths of the plurality of remote uplink paths of the uplink band should be adjusted; and

(iii) if the uplink gain of the remote uplink paths of the uplink band should be adjusted;

direct a remote uplink gain control circuit for each remote uplink path of the uplink band, to adjust the uplink gain of the respective remote uplink path by a defined remote uplink band gain level.

2. The gain control system of claim 1, wherein the central controller is configured to determine if the uplink gain of the remote uplink paths of the plurality of remote uplink paths of the uplink band should be adjusted by being configured to:

(a) identify as high power remote uplink paths any remote uplink paths of the plurality of remote uplink paths of the uplink band that have a remote uplink band power measurement above a remote uplink threshold power level; and

(b) if a number of remote uplink paths of the plurality of remote uplink paths of the uplink band identified as high power remote uplink paths exceeds a high power remote uplink path threshold level;

direct the remote uplink gain control circuit for each remote uplink path of the uplink band to reduce the uplink gain of the respective remote uplink path by the defined remote uplink band gain level.

3. The gain control system of claim 2, further comprising a central unit comprising:

the central controller;

a plurality of head-end uplink paths each carrying at least one uplink band communications signal; and

a plurality of head-end uplink gain control circuits each coupled to a corresponding head-end uplink path, wherein;

the central controller is further configured to;

(c) if the number of remote uplink paths of the plurality of remote uplink paths of the uplink band identified as high power remote uplink paths exceeds the high power remote uplink path threshold level;

direct a head-end uplink gain control circuit corresponding to the head-end uplink path for the uplink band to increase the uplink gain of the corresponding head-end uplink path for the uplink band by the defined remote uplink band gain level.

4. The gain control system of claim 3, wherein each head-end uplink gain control circuit among the plurality of head-end uplink gain control circuits is included in a radio interface module (RIM) for the corresponding uplink band.

5. The gain control system of claim 2, wherein the high power remote uplink path threshold level is comprised of a ratio of a number of remote uplink paths of the uplink band identified as high power remote uplink paths to a total number of remote uplink paths of the plurality of uplink paths of the uplink band.

6. The gain control system of claim 2, wherein:

each remote uplink gain control circuit comprises a remote uplink automatic level control (ALC) circuit further configured to limit a remote uplink power level of the remote uplink path based on a remote uplink gain adjustment signal received from the central controller; and

the central controller is configured to identify as high power remote uplink paths any remote uplink paths of the plurality of remote uplink paths of the uplink band that have activated the remote uplink ALC circuit.

7. The gain control system of claim 1, wherein the defined remote uplink band gain level is lower than 10 dB.

8. The gain control system of claim 1, wherein the defined remote uplink band gain level is approximately 1 dB.

9. The gain control system of claim 1, further comprising the central controller repeatedly performing tasks (i)-(iii).

10. The gain control system of claim 1, wherein the central controller is configured to determine if the uplink gain of the remote uplink paths of the plurality of remote uplink paths of the uplink band should be adjusted by being configured to:

(a) identify as high power remote uplink paths, any remote uplink paths of the plurality of remote uplink paths of the uplink band that have a remote uplink band power measurement above a remote uplink threshold power level; and

(b) if the number of remote uplink paths of the plurality of remote uplink paths of the uplink band identified as high power remote uplink paths is less than a second high power remote uplink path threshold level;

direct the remote uplink gain control circuit for each remote uplink path of the uplink band to increase the uplink gain of the respective remote uplink path by the defined remote uplink band gain level.

11. The gain control system of claim 3, wherein the central controller is configured to:

if a number of remote uplink paths of the plurality of remote uplink paths of the uplink band that were identified as high power remote uplink paths is less than the second high power remote uplink path threshold level;

direct a head-end uplink gain control circuit for the uplink band to reduce the uplink gain of the uplink band by the defined remote uplink band gain level.

12. The gain control system of claim 1, wherein the central controller is further configured to set the uplink gain of the plurality of remote uplink paths to an initial remote uplink band gain level before performing tasks (i)-(iii).

13. The gain control system of claim 12, wherein the initial remote uplink band gain level is comprised of a maximum remote uplink band gain level, and wherein the maximum remote uplink band gain level is in the range of 10 dB to 30 dB.

14. A method of providing system-wide uplink band gain control in a distributed antenna system (DAS), based on per-band gain control of remote uplink paths in remote units, comprising:

for each uplink band of a plurality of uplink bands in the DAS;

(i) receiving remote uplink band power measurements for each remote uplink path of the uplink band;

(ii) determining if an uplink gain of the remote uplink paths of a plurality of remote uplink paths of the uplink band should be adjusted; and

(iii) if the uplink gain of the remote uplink paths of the plurality of remote uplink paths of the uplink band should be adjusted;

directing a remote uplink gain control circuit for each remote uplink path of the uplink band to adjust the uplink gain of the respective remote uplink path by a defined remote uplink band gain level.

15. The method of claim 14, wherein determining if the uplink gain of the remote uplink paths of the plurality of remote uplink paths of the uplink band should be adjusted comprises:

(a) identifying as high power remote uplink paths any remote uplink paths of the plurality of remote uplink paths of the uplink band that have a remote uplink band power measurement above a remote uplink threshold power level; and

(b) if the number of remote uplink paths of the uplink band identified as high power remote uplink paths exceeds a high power remote uplink path threshold level;

directing the remote uplink gain control circuit for each remote uplink path of the uplink band to reduce the uplink gain of the respective remote uplink path by the defined remote uplink band gain level.

16. The method of claim 14, wherein determining if the uplink gain of the remote uplink paths of the plurality of remote uplink paths of the uplink band should be adjusted comprises:

(a) identifying as high power remote uplink paths, any remote uplink paths of the plurality of remote uplink paths of the uplink band that have a remote uplink band power measurement above a remote uplink threshold power level; and

(b) if the number of remote uplink paths of the uplink band identified as high power remote uplink paths is less than a second high power remote uplink path threshold level;

directing the remote uplink gain control circuit for each remote uplink path of the uplink band to increase the uplink gain of the respective remote uplink path by the defined remote uplink band gain level.

17. The method of claim 14, further comprising repeatedly performing tasks (i)-(iii).