Systems and methods for ripple communication decoding
The embodiments described herein provide devices and methods to facilitate ripple control communication. Specifically, the embodiments provide devices and methods for decoding ripple control data from ripple signals, such as ripple signals that have been superimposed over power signals used to transmit power. These embodiments provide devices and methods that use band-pass filter, signal multiplier, fast and slow low-pass filters, and accumulate a difference between outputs of these slow and fast low-pass filters. This accumulated difference is then used to decode the ripple control data.
1. A ripple control receiver, comprising:
a ripple signal extractor configured to receive a power signal having a superimposed ripple signal and extract the ripple signal from the power signal, wherein the ripple signal extractor comprises
a band-pass filter having an input and an output, the band-pass filter configured to receive the power signal having the superimposed ripple communication signal, and
a signal-squaring element having an input and an output, the signal-squaring element input coupled to the band-pass filter output, the signal-squaring element output coupled to a fast low-pass filter and a slow low-pass filter;
the fast low-pass filter configured to receive the extracted ripple signal and generate a first filtered ripple signal;
the slow low-pass filter configured to receive the extracted ripple signal and generate a second filtered ripple signal;
an accumulator configured to accumulate a difference between the first filtered ripple signal and the second filtered ripple signal and generate an accumulated value in response to the accumulated difference; and
decoding logic configured to receive the accumulated value and decode ripple control data from the accumulated value.
2. The ripple control receiver of claim 1 , wherein the first filtered ripple signal comprises a relatively fast varying mean square of the ripple signal and wherein the second filtered ripple signal comprises a relatively slow varying mean square of the ripple signal.
3. The ripple control receiver of claim 1 , wherein the decoding logic is configured receive the accumulated value and decode ripple control data from the accumulated value by virtue of being configured to
assert a ripple control data signal in response to the accumulated value being above a threshold; and
de-assert the ripple control data in response to the accumulated value being below the threshold.
4. The ripple control receiver of claim 1 , wherein the decoding logic is configured receive the accumulated value and decode ripple control data from the accumulated value by virtue of being configured to
generate a logic high when the accumulated value is above a threshold; and
generate a logic low when the accumulated value is below the threshold.
5. The ripple control receiver of claim 1 , wherein the decoding logic is further configured to reset the accumulator in response to the accumulated value rising above an upper limit or dropping below a lower limit.
6. The ripple control receiver of claim 1 , further comprising:
a signal-level shifter configured to apply an amplitude shift the second filtered ripple signal.
7. The ripple control receiver of claim 1 , wherein the ripple control receiver is implemented with a power meter to facilitate communication with the power meter.
8. The ripple control receiver of claim 1 , wherein the ripple control receiver is coupled to an appliance to facilitate communication with the appliance.
9. A ripple control receiver, comprising:
a band-pass filter having an input and an output, the band-pass filter input configured to receive a power signal having a superimposed ripple communication signal;
a signal-squaring element having an input and an output, the signal-squaring filter input coupled to the band-pass filter output;
a fast low-pass filter having an input and an output, the fast low-pass filter input coupled to the signal-squaring filter output and configured to output a first filtered ripple signal, the first filtered ripple signal comprising a relatively fast varying mean square of the ripple signal;
a slow low-pass filter having an input and an output, the slow low-pass filter input coupled to the signal-squaring filter output and configured to output a second filtered ripple signal, the second filtered ripple signal comprising a relatively slow varying mean square of the ripple signal;
a signal-level shifter having an output;
a first summer having a first input, a second input, and an output, the first input coupled to the slow low-pass filter output, and the second input coupled to the signal-level shifter output;
a second summer having a first input, a second input, and an output, the first input coupled to the fast low-pass filter output, and the second input coupled to the first summer output;
an accumulator having an input and an output, the accumulator input coupled to second summer output, the accumulator configured to accumulate a difference between the first filtered ripple signal and the second filtered ripple signal and generate an accumulated value in response to the accumulated difference; and
decoding logic having an input and an output, the decoding logic input coupled to the accumulator output, the decoding logic output configured to receive the accumulated value and decode ripple control data from the accumulated value.
10. The ripple control receiver of claim 9 , wherein the ripple control receiver is implemented with a power meter to facilitate communication with the power meter.
11. The ripple control receiver of claim 9 , wherein the ripple control receiver is coupled to an appliance to facilitate communication with the appliance.