Individualized gain control of uplink paths in remote units in a distributed antenna system (DAS) based on individual remote unit contribution to combined uplink power

• US 9,980,237 B2
• Filed: 06/09/2017
• Issued: 05/22/2018
• Est. Priority Date: 03/28/2014
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications Wireless Ltd. (Corning Incorporated)
• Inventors: Harel, Dror
• Primary Examiner(s): Elliott, IV, Benjamin H
• Application Number:
  US15/618,237
• Publication Number:
  US 20170280401A1
• Time in Patent Office: 347 Days
• CPC Class Codes: H04B 17/20 of receivers
• 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 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

Individualized gain control of uplink paths in remote units in a wireless communication system based on individual remote unit contribution to combined uplink power is disclosed. The gain level is reduced for uplink paths of individual remote units that provide higher power contribution to the combined uplink power of a combined uplink communications signal received in the central unit. This allows the initial uplink gain of all remote units to be set higher to increase sensitivity, because the gain of the remote units that provide higher power contributions to the combined uplink power in the central unit can be reduced if the combined uplink power exceeds the desired threshold power level. The gain of the remote units that provide higher power contributions to the combined uplink power in the central unit can be reduced without reducing the gain in the other remote units that would otherwise reduce their sensitivity.

Claims

1. A wireless communication system, comprising:

a central unit configured to;

receive at least one downlink communications signal from a network;

distribute the received at least one downlink communications signal to a plurality of remote units;

receive a plurality of uplink communications signals from the plurality of remote units;

combine the received plurality of uplink communications signals into a combined uplink communications signal in a central uplink path; and

distribute the received plurality of uplink communications signals to the network;

a central uplink power measurement circuit coupled to the central uplink path in carrying the combined uplink communications signal, the central uplink power measurement circuit configured to;

measure a combined uplink power of the combined uplink communications signal; and

provide a combined uplink power measurement indicative of the combined uplink power of the combined uplink communications signal;

a central uplink gain control circuit disposed in the central uplink path in the central unit, the central uplink gain control circuit configured to adjust a combined uplink gain of the central uplink path based on a combined uplink gain adjustment signal; and

a central controller configured to;

(a) receive the combined uplink power measurement indicative of the combined uplink power of the combined uplink communications signal;

(b) receive individual remote uplink power measurements of a remote uplink power for each remote uplink path of the plurality of remote units; and

(c) determine if the combined uplink power measurement is greater than a central uplink threshold power level;

(d) if the combined uplink power measurement is greater than the central uplink threshold power level;

identify as a high power remote uplink path, at least one remote uplink path in at least one remote unit among the plurality of remote units that have an individual remote uplink power measurement above a remote uplink threshold power level; and

send at least one remote uplink gain control signal to a remote uplink gain control circuit for the at least one remote uplink path identified as a high power remote uplink path in at least one remote unit among the plurality of remote units, to reduce the uplink gain of the respective remote uplink path by a defined remote uplink gain level reduction;

the plurality of remote units each configured to;

receive the at least one downlink communications signal from the central unit;

distribute the received at least one downlink communications signal to at least one client device;

receive at least one uplink communications signal among the plurality of uplink communications signals in at least one remote uplink path from the at least one client device; and

distribute the received at least one uplink communications signal among the plurality of uplink communications signals to the central unit.

2. The wireless communication system of claim 1, wherein the central controller is configured to repeatedly perform tasks (a)-(d).

3. The wireless communication system of claim 2, wherein if the combined uplink power measurement is greater than a central uplink threshold power level, the central controller is configured to:

identify as the high power remote uplink path, a plurality of remote uplink paths in each remote unit among the plurality of remote units that have the individual remote uplink power measurement above the remote uplink threshold power level; and

direct the remote uplink gain control circuit for each remote uplink path among the plurality of remote uplink paths identified as a high power remote uplink path in each remote unit among the plurality of remote units, to reduce the uplink gain of the respective remote uplink path by a defined remote uplink gain level reduction.

4. The wireless communication system of claim 2, wherein the central uplink gain control circuit comprises a central uplink automatic level control (ALC) circuit configured to limit the combined uplink gain of the central uplink path based on the combined uplink gain adjustment signal;

wherein the central controller is configured to;

determine if the combined uplink power measurement is different that a central uplink threshold power level by being configured to determine if the combined uplink power measurement exceeds the central uplink threshold power level; and

if the combined uplink power measurement exceeds the central uplink threshold power level, send a combined uplink gain adjustment signal to the central uplink gain control circuit to attenuate the combined uplink gain of the central uplink path.

5. The wireless communication system of claim 2, wherein the central uplink gain control circuit comprises a central uplink automatic gain control (AGC) circuit configured to adjust the combined uplink gain of the central uplink path based on the combined uplink gain adjustment signal.

6. The wireless communication system of claim 2, wherein each remote unit among the plurality of remote units further comprises:

at least one remote uplink power measurement circuit coupled to the at least one remote uplink path carrying the received at least one uplink communications signal, the at least one remote uplink power measurement circuit configured to;

measure a remote uplink power of the at least one uplink communications signal in the at least one remote uplink path; and

provide at least one remote uplink power measurement indicative of the remote uplink power of the at least one uplink communications signal in the at least one remote uplink path;

at least one remote uplink gain control circuit disposed in the at least one remote uplink path, the at least one remote uplink gain control circuit configured to adjust the remote uplink gain of the at least one remote uplink path based on at least one remote uplink gain adjustment signal; and

at least one remote controller configured to;

receive the at least one remote uplink power measurement indicative of the remote uplink power of the at least one uplink communications signal in the at least one remote uplink path;

generate the at least one remote uplink gain adjustment signal based on the at least one remote uplink power measurement;

receive the at least one remote uplink gain control signal; and

generate the at least one remote uplink gain adjustment signal based on the at least one remote uplink gain control signal.

7. The wireless communication system of claim 6, wherein the at least one remote controller is comprised of a single remote controller.

8. The wireless communication system of claim 6, wherein:

the at least one remote uplink path is comprised of a plurality of remote uplink paths each associated with a frequency band;

the at least one remote uplink power measurement circuit further comprises a plurality of remote uplink power measurement circuits each coupled to a remote uplink path among the plurality of remote uplink paths, each remote uplink power measurement circuit among the plurality of remote uplink power measurement circuits configured to;

measure a remote uplink power of an uplink communications signal among the plurality of uplink communications signals in a remote uplink path among the plurality of remote uplink paths; and

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

the at least one remote uplink gain control circuit further comprises a plurality of remote uplink gain control circuits disposed in a remote uplink path among the plurality of remote uplink paths, each remote uplink gain control circuit among the plurality of remote uplink gain control circuits configured to adjust the remote uplink gain of the remote uplink path based on a remote uplink gain adjustment signal for the remote uplink path;

at least one remote controller configured to;

receive a plurality of remote uplink power measurements indicative of the remote uplink power of the plurality of uplink communications signals in the plurality of remote uplink paths;

generate a plurality of remote uplink gain adjustment signals each based on a remote uplink power measurement among the plurality of remote uplink power measurements;

receive the at least one remote uplink gain control signal; and

generate a plurality of the remote uplink gain adjustment signals each based on the at least one remote uplink gain control signal.

9. The wireless communication system of claim 6, wherein the at least one remote uplink power measurement circuit and the at least one remote uplink gain control circuit are provided in at least one remote uplink gain control system.

10. The wireless communication system of claim 1, wherein:

the central unit is configured to;

distribute the received at least one downlink communications signal over a plurality of downlink communications media to the plurality of remote units; and

receive an uplink communications signal among the received plurality of uplink communications signals over an uplink communications medium among a plurality of uplink communications media from each remote unit among the plurality of remote units;

each remote unit among the plurality of remote units unit are communicatively coupled to a downlink communications medium among the plurality of downlink communications media, and communicatively coupled to an uplink communications medium among the plurality of uplink communications media;

the plurality of remote units each configured to;

receive the at least one downlink communications signal over a downlink communications medium among the plurality of downlink communications media from the central unit; and

distribute the received at least one uplink communications signal among the plurality of uplink communications signals over an uplink communications medium among the plurality of uplink communications media to the central unit.

11. The wireless communication system of claim 10, wherein each downlink communications medium among the plurality of downlink communications media communicatively coupled to a remote unit among the plurality of remote units, and the uplink communications medium among the plurality of uplink communications media communicatively coupled to the remote unit among the plurality of remote units, are comprised of a common communications medium.

12. The wireless communication system of claim 1, wherein the central unit is configured to receive the plurality of uplink communications signals comprised of a plurality of optical uplink communications signals from the plurality of remote units;

the central unit further comprising a plurality of central optical-to-electrical (O-E) converters each configured to convert a received optical uplink communications signal among the plurality of optical uplink communications signals to an electrical uplink communications signal to provide a plurality of electrical uplink communications signals;

the central unit configured to combine the received plurality of electrical uplink communications signals into a combined electrical uplink communications signal in the central uplink path.

13. A wireless communication system, comprising:

a central unit configured to;

receive at least one downlink communications signal;

distribute the received at least one downlink communications signal to a plurality of remote units;

receive a plurality of optical uplink communications signals from the plurality of remote units;

combine the received plurality of optical uplink communications signals into a combined uplink communications signal in a central uplink path; and

distribute the received plurality of optical uplink communications signals;

a central uplink power measurement circuit coupled to the central uplink path in carrying the combined uplink communications signal, the central uplink power measurement circuit configured to;

measure a combined uplink power of the combined uplink communications signal; and

provide a combined uplink power measurement indicative of the combined uplink power of the combined uplink communications signal;

a central uplink gain control circuit disposed in the central uplink path in the central unit, the central uplink gain control circuit configured to adjust a combined uplink gain of the central uplink path based on a combined uplink gain adjustment signal; and

a central controller configured to;

(a) receive the combined uplink power measurement indicative of the combined uplink power of the combined uplink communications signal;

(b) receive individual remote uplink power measurements of a remote uplink power for each remote uplink path of the plurality of remote units; and

(c) determine if the combined uplink power measurement is greater than a central uplink threshold power level;

(d) if the combined uplink power measurement is greater than the central uplink threshold power level;

identify as a high power remote uplink path, at least one remote uplink path in at least one remote unit among the plurality of remote units that have an individual remote uplink power measurement above a remote uplink threshold power level; and

send at least one remote uplink gain control signal to a remote uplink gain control circuit for the at least one remote uplink path identified as a high power remote uplink path in at least one remote unit among the plurality of remote units, to reduce the uplink gain of the respective remote uplink path by a defined remote uplink gain level reduction;

the plurality of remote units each configured to;

receive the at least one downlink communications signal from the central unit;

distribute the received at least one downlink communications signal to at least one client device;

receive at least one uplink communications signal in at least one remote uplink path from the at least one client device; and

distribute the received at least one uplink communications signal as at least one optical uplink communications signal among the plurality of optical uplink communications signals to the central unit.

14. The wireless communication system of claim 13, wherein the central controller is configured to repeatedly perform tasks (a)-(d), and wherein the remote units are distributed among multiple floors of a building infrastructure.

15. The wireless communication system of claim 14, wherein the central uplink gain control circuit comprises a central uplink automatic gain control (AGC) circuit configured to adjust the combined uplink gain of the central uplink path based on the combined uplink gain adjustment signal.

16. The wireless communication system of claim 14, wherein the central unit is configured to distribute the received at least one downlink communications signal over a plurality of optical downlink communications media to the plurality of remote units.

17. The wireless communication system of claim 16, wherein each remote unit is communicatively coupled to an optical downlink communications medium among the plurality of optical downlink communications media.