System, apparatus and method for time synchronization of delayed data streams by matching of wavelet coefficients

Patent metadata

Field	Value
Publication number	US-10789965-B2
Application number	US-201816026131-A
Country	US
Kind code	B2
Filing date	Jul 3, 2018
Priority date	Jul 3, 2018
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

In one example, an apparatus includes: a wavelet transform engine to receive a first signal stream and perform a wavelet transform on a first time domain sample of the first signal stream, the first wavelet transform engine to output at least one first coefficient for a first frequency range; an energy calculation circuit to compute a first energy signature for the at least one first coefficient; and a correlation circuit to generate a correlation value using the first energy signature, a second energy signature and a plurality of previous energy signatures.

First claim

What is claimed is:

1. An apparatus comprising:
a receiver to receive and process a first radio frequency (RF) signal and a second RF signal to obtain a first signal stream and a second signal stream;
a first wavelet transform engine to receive the first signal stream and perform a wavelet transform on a first time domain sample of the first signal stream, the first wavelet transform engine to output at least one first coefficient for a first frequency range;
a first energy calculation circuit to compute a first energy signature for the at least one first coefficient;
a first filter to filter the first energy signature;
a first normalization circuit to generate a first normalized value based on the first energy signature and the filtered first energy signature;
a correlation circuit to generate a correlation value using the first normalized value, a second normalized value and a plurality of previous first normalized values and second normalized values; and
a peak search circuit coupled to the correlation circuit to generate a reliability metric based at least in part on information from the correlation circuit, the peak search circuit to provide the reliability metric to an audio processor, wherein the audio processor is to seamlessly link the first signal stream and the second signal stream based at least in part on the reliability metric.

2. The apparatus of claim 1 , wherein the correlation circuit is to store the correlation value in a correlation storage.

3. The apparatus of claim 2 , wherein the peak search circuit is to identify a peak value of a plurality of correlation values stored in the correlation storage.

4. The apparatus of claim 3 , wherein the peak search circuit is to identify a second peak value of the plurality of correlation values stored in the correlation storage, the second peak value less than the first peak value.

5. The apparatus of claim 4 , wherein the peak search circuit is to calculate a first ratio based on the peak value and the second peak value.

6. The apparatus of claim 5 , wherein the peak search circuit is to calculate a second ratio based on the peak value and an average of the plurality of correlation values in the correlation storage.

7. The apparatus of claim 6 , wherein the peak search circuit is to generate the reliability metric based on the first ratio and the second ratio.

8. The apparatus of claim 7 , wherein the peak search circuit is to identify a correlation between the first signal stream and the second signal stream in response to the reliability metric being greater than a first threshold.

9. The apparatus of claim 8 , wherein the peak search circuit is to identify the correlation in response to the reliability metric being less than the first threshold and greater than a second threshold for at least a first plurality of consecutive windows.

10. The apparatus of claim 1 , wherein the wavelet transform engine comprises:
a first filter chain including a first plurality of delay elements and a first plurality of downsamplers, the first filter chain to generate a plurality of first coefficients, the plurality of first coefficients including the at least one first coefficient; and
a second filter chain including a second plurality of delay elements and a second plurality of downsamplers, the second filter chain to generate a plurality of second coefficients, the plurality of second coefficients including the at least one second coefficient.

11. At least one non-transitory computer readable medium including instructions that when executed cause a system to perform a method comprising:
receiving and processing, in a receiver, a first radio frequency (RF) signal and a second RF signal;
demodulating, in a first demodulator, the first processed signal to generate a first demodulated signal;
demodulating, in a second demodulator, the second processed signal to generate a second demodulated signal;
receiving, in a processor, the first demodulated signal and the second demodulated signal;
performing, in the processor, a wavelet transform on first time domain samples of the first demodulated signal and second time domain samples of the second demodulated signal;
outputting a first detail coefficient for a selected frequency range based on the wavelet transform of the first time domain samples and outputting a second detail coefficient for the selected frequency range based on the wavelet transform of the second time domain samples;
computing a first energy signature based on the first detail coefficient and computing a second energy signature based on the second detail coefficient;
performing a cross-correlation on a plurality of first energy signatures and a plurality of second energy signatures stored in at least one buffer to identify common content in the first demodulated signal and the second demodulated signal, the first energy signature one of the first plurality of first energy signatures and the second energy signature one of the plurality of second energy signatures; and
communicating information regarding the common content to an audio processor to enable the audio processor to perform a blend or handover with a first audio signal obtained from the first demodulated signal and a second audio signal obtained from the second demodulated signal.

12. The at least one non-transitory computer readable medium of claim 11 , further comprising instructions that when executed cause the system to perform the method further comprising:
filtering the first energy signature into a filtered first energy signature and normalizing the first energy signature based on the filtered first energy signature;
filtering the second energy signature into a filtered second energy signature and normalizing the second energy signature based on the filtered second energy signature; and
storing the normalized first energy signature and storing the normalized second energy signature in the at least one buffer.

13. The at least one non-transitory computer readable medium of claim 11 , further comprising instructions that when executed cause the system to perform the method further comprising:
determining whether there are a sufficient number of first energy signatures and second energy signatures stored in the at least one buffer; and
in response to the determination, performing the cross-correlation on the plurality of first energy signatures and the plurality of second energy signatures.

14. The at least one non-transitory computer readable medium of claim 11 , further comprising instructions that when executed cause the system to perform the method further comprising:
identifying a peak value based on the cross-correlation;
identifying a second peak value based on the cross-correlation, wherein the second peak value is less than the peak value; and
calculating an average cross-correlation value based on a plurality of cross-correlation values.

15. The at least one non-transitory computer readable medium of claim 14 , further comprising instructions that when executed cause the system to perform the method further comprising:
determining a first ratio based on the peak value and the second peak value; and
determining a second ratio based on the peak value and the average cross-correlation value.

16. The at least one non-transitory computer readable medium of claim 15 , wherein the method further comprises determining a reliability metric using the first ratio and the second ratio.

17. The at least one non-transitory computer readable medium of claim 16 , wherein the method further comprises:
outputting a delay estimate ba

Assignees

• Silicon Lab Inc

Inventors

• Wallace Bradley Arthur
• Alelyunas Carl Harry

Classifications

• G06F2218/10

  by analysing the shape of a waveform, e.g. extracting parameters relating to peaks · CPC title

• G06F2218/14

  by matching peak patterns · CPC title

• G10L19/0216 Primary

  using wavelet decomposition · CPC title

• G06F17/148 Primary

  Wavelet transforms · CPC title

• G06K9/0053

  Physics · mapped topic