Receiver gain adjustment

• US 8,428,201 B1
• Filed: 03/02/2010
• Issued: 04/23/2013
• Est. Priority Date: 03/02/2010
• Status: Active Grant

• Current Assignee: Landis+Gyr Inc. (Landis+Gyr Group AG)
• Original Assignee: Landis+Gyr Inc. (Landis+Gyr Group AG)
• Inventors: McHann, Stanley E. Jr., Amweg, Jim
• Primary Examiner(s): Flores, Leon
• Application Number:
  US12/715,508
• Time in Patent Office: 1,148 Days
• Field of Search: 375/257, 375/285, 375/316, 375/345, 455/127.2, 455/219, 455/232.1, 455/234.1
• US Class Current: 375/345
• CPC Class Codes: H03G 3/3089 Control of digital or coded signals
• CPC Class Codes: H04B 2203/5425 improving S/N by matching impedance, noise reduction, gain control
• CPC Class Codes: H04B 2203/5441 Wireless systems or telephone
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04B 2203/5495 having measurements and testing channel
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines

Abstract

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for selecting receiver gain adjustment values. In one aspect, a method includes receiving aggregate signal characteristic values (“aggregate values”) for a plurality of signals being received over active channels of a power line communications network, the aggregate values being computed based on signal characteristic values for each of the signals being received over the active channels. Using the aggregate values, a determination is made that one or more of the aggregate values have been outside of a valid range of signal characteristic values over a specified period. In response to determining that the aggregate values have been outside of the valid range, a receiver gain adjustment value is selected based on the aggregate values and a receiver gain of a receiver that receives the signals is adjusted.

Claims

1. A method, comprising:

receiving, by a data processing apparatus, aggregate signal characteristic values for a plurality of signals being received over active channels of a power line communications network in which power lines are used to distribute power to customers located in designated geographic areas and to provide data channels for communicating the aggregate signal characteristic values, the aggregate signal characteristic values being a function of the distributed power and being computed based on measured signal characteristic values for each of the signals being received over the active channels, the active communications channels being communications channels that have been assigned to communications nodes;

determining, by the data processing apparatus, that one or more of the aggregate signal characteristic values have been outside of a valid range of signal characteristic values over a specified period, the valid range of signal characteristic values specifying at least a high characteristic threshold and a low characteristic threshold;

in response to determining that the aggregate signal characteristic values have been outside of the valid range, selecting, by the data processing apparatus, a receiver gain adjustment value based on the aggregate signal characteristic values; and

adjusting, by the data processing apparatus, a receiver gain of a receiver that receives the signals over the power line communications network based on the receiver gain adjustment value.

2. The method of claim 1, wherein selecting the receiver gain adjustment value comprises:

selecting an initial receiver gain adjustment value based on an aggregate high amplitude for the signals violating a high amplitude threshold;

determining that an aggregate mean amplitude violates a high mean threshold for the signals that specifies a highest acceptable aggregate mean amplitude for the signals;

determining that the aggregate high amplitude for the signals has decreased over a specified time;

determining that signal to noise ratios for the signals have decreased over the specified time; and

in response to determining that the aggregate mean amplitude violates a high mean threshold, determining that the aggregate high amplitude for the signals has decreased, and determining that signal to noise ratios for the signals have decreased, selecting a final receiver gain adjustment value that is higher than the initial receiver gain adjustment value based on an amount by which the aggregate high amplitude and the signal to noise ratio have decreased over the specified time.

3. The method of claim 2, wherein determining that signal amplitude values of the signals have decreased:

computing an aggregate mean amplitude for active channels, each active channel being a channel over which a node in the network is communicating; and

determining that the aggregate mean amplitude for the active channels is lower than at least one previously computed aggregate mean amplitude for the active channels.

4. The method of claim 1, wherein selecting the receiver gain adjustment value comprises:

selecting an initial receiver gain adjustment value based on an aggregate high amplitude for the signals violating a high amplitude threshold;

determining that an aggregate amplitude swing violates an amplitude swing threshold, the amplitude swing threshold specifying a minimum acceptable amplitude swing for signals received over active channels;

determining that at least one of the aggregate high amplitude and a signal to noise ratio for the signals has decreased over a specified time; and

selecting a final receiver gain adjustment value that is higher than the initial receiver gain adjustment value.

5. The method of claim 4, wherein determining that at least one of the aggregate high amplitude and the signal to noise ratio has decreased over time comprises:

computing an aggregate high amplitude for the active channels, each active channel being a channel over which valid data is being received; and

determining that the aggregate high amplitude for the active channels is lower than at least one previously computed, has decreased over time and is lower than at least one previously computed aggregate high amplitude for the active channels.

6. The method of claim 1, further comprising:

initializing aggregate signal characteristics values of a signal characteristic log to default values; and

storing aggregate signal characteristic values in the characteristic log, the stored values including an aggregate high amplitude and an aggregate low amplitude.

7. The method of claim 1, wherein determining that one or more of the aggregate signal characteristic values have been outside of a valid range of signal characteristic values comprises determining that an aggregate high amplitude for the signals has been higher than a high amplitude threshold.

8. The method of claim 7, wherein selecting a receiver gain adjustment value based on the aggregate signal characteristics comprises selecting an initial receiver gain adjustment value based on a magnitude by which the aggregate high amplitude exceeds the high amplitude threshold.

9. The method of claim 8, further comprising selecting a final receiver gain adjustment value that is higher than the initial receiver gain adjustment value when the aggregate high amplitude or a signal to noise ratio for the signals has decreased over a specified time.

10. The method of claim 1, wherein determining that one or more of the aggregate signal characteristic values have been outside of a valid range of signal characteristic values comprises determining that an aggregate low amplitude for the signals has been lower than a low amplitude threshold.

11. The method of claim 10, wherein selecting a receiver gain adjustment value based on the aggregate signal characteristics comprises selecting an initial receiver gain adjustment value based on a magnitude by which the aggregate low amplitude is less than the low amplitude threshold.

12. The method of claim 11, further comprising:

determining that an aggregate mean value for the signals violates a low mean threshold representing a lowest acceptable aggregate mean value for signals received over active channels, the active channels being channels over which nodes in the network are transmitting data;

determining that the aggregate low amplitude or an aggregate signal to noise ratio for the signals have decreased over time; and

in response to determining that an aggregate mean value for the signals violates a low mean threshold and determining that the aggregate low amplitude or an aggregate signal to noise ratio for the signals have decreased over time, selecting a final receiver gain adjustment value that is lower than the initial receiver gain adjustment value.

13. The method of claim 1, wherein receiving aggregate signal characteristic values comprises receiving a vector of values, where each value in the vector represents a signal characteristic value for a signal being received over a corresponding channel.

14. A system having a substation processing unit for facilitating distribution of power over power lines which, along with the substation processing unit, forms part of a power line distribution network, the system comprising:

a power line substation, including the substation processing unit;

the substation processing unit including a receiver and at least one processor, the substation processing unit being configured to receive signals over a plurality of active channels in a power line communications network and log signal characteristic values for the plurality of signals, the active channels being communications channels that have been assigned to communications nodes; and

a receiver adjustment subsystem coupled to the substation processing unit, the receiver adjustment subsystem including at least one processor and being configured to generate aggregate signal characteristic values for the plurality of signals, determine that one or more of the aggregate signal characteristics have been outside of a valid range of signal characteristic values, select, in response to the determination that the aggregate signal characteristics have been outside of the valid range, a receiver gain adjustment value based on the aggregate signal characteristics, and adjust a receiver gain for the receiver of the substation processing unit, the aggregate signal characteristic values being a function of the distributed power and being computed based on signal characteristic values for each of the signals being received over the active channels, and the valid range of signal characteristic values specifying at least a high characteristic threshold and a low characteristic threshold.

15. The system of claim 14, wherein the receiver adjustment subsystem is further configured to select an initial receiver gain adjustment value based on an aggregate high amplitude for the signals violating a high amplitude threshold, determine that an aggregate mean amplitude for the signals violates a high mean threshold that specifies a highest acceptable aggregate mean amplitude for the signals, determine that the aggregate high amplitude for the signals has decreased over a specified time and select a final receiver gain adjustment value that is higher than the initial receiver gain adjustment value based on an amount by which the aggregate high amplitude and a signal to noise ratio have decreased over the specified time.

16. The system of claim 14, wherein the receiver adjustment subsystem is further configured to select an initial receiver gain adjustment value based on an aggregate high amplitude for the signals violating a high amplitude threshold, determine that an aggregate amplitude swing violates an amplitude swing threshold, the amplitude swing threshold specifying a minimum acceptable amplitude swing for signals received over active channels, determine that at least one of the aggregate high amplitude and a signal to noise ratio for the signals has decreased over a specified time;

and select a final receiver gain adjustment value that is higher than the initial receiver gain adjustment value.

17. The system of claim 14, wherein the receiver adjustment subsystem is further configured to determine that an aggregate high amplitude for the signals has been higher than a high amplitude threshold.

18. The system of claim 17, wherein the receiver adjustment subsystem is further configured to select an initial receiver gain adjustment value based on a magnitude by which the aggregate high amplitude exceeds the high amplitude threshold.

19. The system of claim 18, wherein the receiver adjustment subsystem is further configured to select a final receiver gain adjustment value that is higher than the initial receiver gain adjustment value when the aggregate high amplitude or a signal to noise ratio for the signals has decreased over a specified time.

20. The system of claim 14, wherein the receiver adjustment subsystem is further configured to determine that an aggregate low amplitude for the signals has been lower than a low amplitude threshold and select an initial receiver gain adjustment value based on a magnitude by which the aggregate low amplitude is less than the low amplitude threshold.

21. The system of claim 20, wherein the receiver adjustment subsystem is further configured to determine that an aggregate mean value for the signals violates a low mean threshold representing a lowest acceptable aggregate mean value for signals received over active channels, the active channels being channels over which nodes in the network are transmitting data, determine that the aggregate low amplitude or an aggregate signal to noise ratio for the signals have decreased over time, and select a final receiver gain adjustment value that is lower than the initial receiver gain adjustment value.

22. A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by a data processing apparatus cause the data processing apparatus to perform operations comprising:

receiving, by a data processing apparatus, aggregate signal characteristic values for a plurality of signals being received over active channels of a power line communications network in which power lines are used to distribute power to customers located in designated geographic areas and to provide data channels for communicating the aggregate signal characteristic values, the aggregate signal characteristic values being a function of the distributed power and being computed based on signal characteristic values for each of the signals being received over the active channels, the active communications channels being communications channels that have been assigned to communications nodes;

determining, by a data processing apparatus, that one or more of the aggregate signal characteristic values have been outside of a valid range of signal characteristic values over a specified period, the valid range of signal characteristic values specifying at least a high characteristic threshold and a low characteristic threshold;

in response to determining that the aggregate signal characteristic values have been outside of the valid range, selecting, by a data processing apparatus, a receiver gain adjustment value based on the aggregate signal characteristics; and

adjusting, by a data processing apparatus, a receiver gain of a receiver that receives the signals over the power line communications network based on the receiver gain adjustment value.