Power distribution line communications with compensation for post modulation
First Claim
1. A method for communicating data from a plurality of endpoint devices to a collector device over a power distribution line, the method comprising:
- detecting an undesirable post modulation of a communication from one of the plurality of endpoint devices and a related loss of orthogonality between multiple orthogonal frequency sub-channels for a communication from an endpoint device of the plurality of endpoint devices, wherein the undesirable post modulation includes inter-channel interference between sub-channels, the communication from the endpoint device of the plurality of endpoint devices is encoded using frequency shift keying (FSK) and the loss of orthogonality is a result of amplitude modulation caused by undesirable post modulation; and
in response to detecting occurrences of the undesirable post modulation of the communication from the one of the plurality of endpoint devices to the collector device over the power distribution line correlating with occurrences of a bit error rate exceeding a threshold error rate, selecting for the endpoint device of the plurality of endpoint devices, a spacing between the multiple orthogonal frequency sub-channels for future communication, wherein selecting the spacing includes selecting a subset of the sub-channels that will not be used.
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Abstract
A system for communicating data over power utility lines includes a plurality of endpoint devices. The endpoint devices can have modulation circuits configured and arranged to modulate data using multiple-orthogonal frequency sub-channels. The endpoint devices can also have a power line interface circuit configured and arranged to transmit the modulated data over a power utility line. A detection module can be configured and arranged to detect undesirable post modulation of a communication from one of the plurality of endpoint devices and to generate a signal responsive to the detected post modulation. The endpoint devices can then set a spacing between the multiple orthogonal frequency sub-channels in response to the signal responsive to the detected post modulation.
65 Citations
20 Claims
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1. A method for communicating data from a plurality of endpoint devices to a collector device over a power distribution line, the method comprising:
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detecting an undesirable post modulation of a communication from one of the plurality of endpoint devices and a related loss of orthogonality between multiple orthogonal frequency sub-channels for a communication from an endpoint device of the plurality of endpoint devices, wherein the undesirable post modulation includes inter-channel interference between sub-channels, the communication from the endpoint device of the plurality of endpoint devices is encoded using frequency shift keying (FSK) and the loss of orthogonality is a result of amplitude modulation caused by undesirable post modulation; and in response to detecting occurrences of the undesirable post modulation of the communication from the one of the plurality of endpoint devices to the collector device over the power distribution line correlating with occurrences of a bit error rate exceeding a threshold error rate, selecting for the endpoint device of the plurality of endpoint devices, a spacing between the multiple orthogonal frequency sub-channels for future communication, wherein selecting the spacing includes selecting a subset of the sub-channels that will not be used. - View Dependent Claims (2, 3, 4)
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5. A method comprising:
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communicating data from a plurality of endpoint devices to a collector device over a power distribution line, the communication of data from each of the plurality of endpoint devices being carried out by modulating data using multiple orthogonal frequency sub-channels and being encoded using frequency shift keying (FSK); detecting undesirable post modulation of a communication from one of the plurality of endpoint devices and a related loss of orthogonality, wherein the undesirable post modulation includes inter-channel interference between sub-channels and the loss of orthogonality is a result of amplitude modulation caused by undesirable post modulation; and in response to detecting occurrences of the undesirable post modulation correlating with occurrences of a bit error rate exceeding a threshold error rate, selecting for the one of the plurality of endpoint devices, a spacing between the multiple orthogonal frequency sub-channels for future communication. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
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14. A system for communicating data over power utility lines, the system comprising:
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a plurality of endpoint devices, each endpoint device including; a modulation circuit configured and arranged to modulate data using multiple orthogonal frequency sub-channels, to encode the data for communication using frequency shift keying (FSK), and to modify a spacing between the multiple orthogonal frequency sub-channels in response to data received at an input; and a power line interface circuit configured and arranged to transmit the modulated data over a power utility line; and a detection module configured and arranged to detect post modulation and a related loss of orthogonality between multiple orthogonal frequency sub-channels in a communication from one of the plurality of endpoint devices and to provide a signal responsive to detected post modulation to the input, wherein the post modulation includes inter-channel interference between sub-channels and the loss of orthogonality is a result of amplitude modulation caused by undesirable post modulation; and wherein the modulation circuit is further configured and arranged to modify the spacing between the multiple orthogonal frequency sub-channels in response to occurrences of the detected post modulation correlating with occurrences of a bit error rate exceeding a threshold error rate. - View Dependent Claims (15, 16, 17, 18, 19)
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20. An apparatus comprising:
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communication circuitry configured and arranged to communicate data from a plurality of endpoint devices to a collector device over a power distribution line, the communicated data from the plurality of endpoint devices to the collector device being encoded using frequency shift keying (FSK); detection circuitry configured and arranged to detect an undesirable post modulation of a communication from one of the plurality of endpoint devices and a related loss of orthogonality between multiple orthogonal frequency sub-channels for a communication from an endpoint device of the plurality of endpoint devices, wherein the undesirable post modulation includes inter-channel interference between sub-channels and the loss of orthogonality is a result of amplitude modulation caused by undesirable post modulation; and signal-processing circuitry configured and arranged to select, for the endpoint device of the plurality of endpoint devices, a spacing between the multiple orthogonal frequency sub-channels for ongoing communication in response to detected occurrences of the undesirable post modulation correlating with occurrences of a bit error rate exceeding a threshold error rate.
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Specification