Apparatus and method of obtaining non-speech data embedded in vocoder packet

• US 8,825,480 B2
• Filed: 06/03/2009
• Issued: 09/02/2014
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Joetten, Christoph A., Sgraja, Christian, Frank, Georg, Huang, Pengjun, Pietsch, Christian, Werner, Marc W., Duni, Ethan R., Baik, Eugene J.
• Primary Examiner(s): MCFADDEN, SUSAN IRIS
• Application Number:
  US12/477,574
• Publication Number:
  US 20090306976A1
• Time in Patent Office: 1,917 Days
• Field of Search: 704/214, 704/237
• US Class Current: 704/237
• CPC Class Codes: G10L 19/00 Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis in musical instruments G10H
• CPC Class Codes: H04J 3/0611 PN codes H04J3/0608 takes precedence
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 5/1415 using control lines
• CPC Class Codes: H04L 5/1423 for simultaneous baseband signals
• CPC Class Codes: H04L 5/1453 of modulation type
• CPC Class Codes: H04L 7/027 extracting the synchronising or clock signal from the received signal spectrum, e.g. by using a resonant or bandpass circuit
• CPC Class Codes: H04L 7/042 Detectors therefor, e.g. correlators, state machines digital correlators in general G06F17/15

Abstract

A system is provided for transmitting information through a speech codec (in-band) such as found in a wireless communication network. A modulator transforms the data into a spectrally noise-like signal based on the mapping of a shaped pulse to predetermined positions within a modulation frame, and the signal is efficiently encoded by a speech codec. A synchronization sequence provides modulation frame timing at the receiver and is detected based on analysis of a correlation peak pattern. A request/response protocol provides reliable transfer of data using message redundancy, retransmission, and/or robust modulation modes dependent on the communication channel conditions.

Claims

1. A method of obtaining non-speech data embedded in a vocoder packet comprising:

receiving and decoding the vocoder packet by a processor;

filtering the decoded vocoder packet until a synchronization signal is detected by the processor, the filtering comprising correlating the decoded vocoder packet with a predetermined sequence to produce the synchronization signal, and searching for a pattern of correlation peaks in the synchronization signal, wherein the searching comprises;

identifying a number of correlation peaks matching an expected pattern, wherein the expected pattern is based on a plurality of negative and positive correlation peaks; and

determining if the number is greater than a predetermined value;

calculating a timing offset based on the synchronization signal by the processor; and

extracting the non-speech data embedded in the decoded vocoder packet based on the timing offset by the processor.

2. The method of claim 1, wherein the correlating comprises applying a sparse filter whose coefficients are the impulse response of the predetermined sequence.

3. The method of claim 1, wherein determining if the number is greater than the predetermined value comprises:

calculating a sum of a number of positive correlation peaks and a number of negative correlation peaks matching the expected pattern; and

determining if the sum is greater than the predetermined value.

4. The method of claim 3 wherein the predetermined value is 80% of the maximum number of positive correlation peaks and negative correlation peaks found in the synchronization signal which meet the expected pattern.

5. The method of claim 1, wherein the searching further comprises:

identifying a number of positive correlation peaks in the synchronization signal;

determining if the time distance between the positive correlation peaks is within a first predetermined range; and

determining if the positive correlation peaks amplitude is greater than a first predetermined threshold.

6. The method of claim 1, wherein the searching further comprises:

identifying a number of negative correlation peaks in the synchronization signal;

determining if the time distance between the negative correlation peaks is within a second predetermined range; and

determining if the negative correlation peaks amplitude is greater than a second predetermined threshold.

7. The method of claim 1, wherein the calculating the timing offset comprises adding the time distance between a positive correlation peak and a reference time instance to the time distance between the positive correlation peak and a negative correlation peak.

8. The method of claim 1, wherein the calculating the timing offset comprises adding the time distance between a negative correlation peak and a reference time instance.

9. The method of claim 1 wherein the extracting comprises:

determining a demodulation frame boundary based on the timing offset;

determining a demodulation type based on a demodulation type indicator;

determining a data signal pulse position using the demodulation frame boundary and the demodulation type; and

calculating an output data symbol based on the data signal pulse position.

10. The method of claim 9 wherein the demodulation type indicator is a predetermined signal.

11. The method of claim 10 wherein the predetermined signal is a sinusoidal signal.

12. The method of claim 10 wherein the predetermined signal is stored in a memory at a position determined by the timing offset.

13. A non-transitory memory storing a computer program that, when executed, causes a computer to perform the acts of:

receiving and decoding a vocoder packet;

filtering the decoded vocoder packet until a synchronization signal is detected the filtering comprising correlating the decoded vocoder packet with a predetermined sequence to produce the synchronization signal, and searching for a pattern of correlation peaks in the synchronization signal, wherein the searching comprises;

identifying a number of correlation peaks matching an expected pattern, wherein the expected pattern is based on a plurality of negative and positive correlation peaks; and

determining if the number is greater than a predetermined value;

calculating a timing offset based on the synchronization signal; and

extracting the non-speech data embedded in the decoded vocoder packet based on the timing offset.

14. An apparatus comprising:

a processor;

a receiver that receives and decodes a vocoder packet;

a filter that filters the decoded vocoder packet until a synchronization signal is detected, wherein the filter comprises a correlator to correlate the decoded vocoder packet with a predetermined sequence to produce the synchronization signal, and a searcher to search for a pattern of correlation peaks in the synchronization signal, wherein the searcher comprises;

a peak identifier for identifying a number of correlation peaks matching an expected pattern, wherein the expected pattern is based on a plurality of negative and positive correlation peaks; and

a peak sum comparator for determining if the number is greater than a predetermined value;

a calculator that calculates a timing offset based on the synchronization signal; and

an extractor that extracts non-speech data embedded in the decoded vocoder packet based on the timing offset.

15. The apparatus of claim 14, wherein the correlator is a sparse filter whose coefficients are the impulse response of the predetermined sequence.

16. The apparatus of claim 14, wherein the peak sum comparator further:

calculates a sum of a number of positive correlation peaks and a number of negative correlation peaks matching the expected pattern; and

determines if the sum is greater than the predetermined value.

17. The apparatus of claim 16 wherein the predetermined value is 80% of the maximum number of positive correlation peaks and negative correlation peaks found in the synchronization signal which meet the expected pattern.

18. The apparatus of claim 14, wherein the searcher further comprises:

a positive peak detector to identify a number of positive correlation peaks in the synchronization signal;

a positive peak time comparator to determine if the time distance between the positive correlation peaks is within a first predetermined range; and

a positive peak amplitude comparator to determine if the positive correlation peaks amplitude is greater than a first predetermined threshold.

19. The apparatus of claim 14, wherein the searcher further comprises:

a negative peak detector to identify a number of negative correlation peaks in the synchronization signal;

a negative peak time comparator to determine if the time distance between the negative correlation peaks is within a second predetermined range; and

a negative peak amplitude comparator to determine if the negative correlation peaks amplitude is greater than a second predetermined threshold.

20. The apparatus of claim 14, wherein the calculator that calculates the timing offset comprises an adder to add the time distance between a positive correlation peak and a reference time instance to the time distance between the positive correlation peak and a negative correlation peak.

21. The apparatus of claim 14, wherein the calculator that calculates the timing offset comprises an adder to add the time distance between a negative correlation peak and a reference time instance.

22. The apparatus of claim 14 wherein the extractor comprises a processor to:

determine a demodulation frame boundary based on the timing offset;

determine a demodulation type based on a demodulation type indicator;

determine a data signal pulse position using the demodulation frame boundary and the demodulation type; and

calculate an output data symbol based on the data signal pulse position.

23. An apparatus comprising:

a processor;

means for receiving and decoding a vocoder packet;

means for filtering the decoded vocoder packet until a synchronization signal is detected, the means for filtering comprising means for correlating the decoded vocoder packet with a predetermined sequence to produce the synchronization signal, and means for searching for a pattern of correlation peaks in the synchronization signal, wherein the means for searching;

identifies a number of correlation peaks matching an expected pattern, wherein the expected pattern is based on a plurality of negative and positive correlation peaks; and

determines if the number is greater than a predetermined value;

means for calculating a timing offset based on the synchronization signal; and

means for extracting the non-speech data embedded in the decoded vocoder packet based on the timing offset.

24. The apparatus of claim 23, wherein the means for correlating applies a sparse filter whose coefficients are the impulse response of the predetermined sequence.

25. The apparatus of claim 23, wherein the means for searching is further configured to:

calculate a sum of a number of positive correlation peaks and a number of negative correlation peaks matching the expected pattern; and

determine if the sum is greater than the predetermined value.

26. The apparatus of claim 25, wherein the predetermined value is 80% of the maximum number of positive correlation peaks and negative correlation peaks found in the synchronization signal which meet the expected pattern.

27. The apparatus of claim 23, wherein the means for searching further:

identifies a number of positive correlation peaks in the synchronization signal;

determines if the time distance between the positive correlation peaks is within a first predetermined range; and

determines if the positive correlation peaks amplitude is greater than a first predetermined threshold.

28. The apparatus of claim 23, wherein the means for searching further:

identifies a number of negative correlation peaks in the synchronization signal;

determines if the time distance between the negative correlation peaks is within a second predetermined range; and

determines if the negative correlation peaks amplitude is greater than a second predetermined threshold.

29. The apparatus of claim 23, wherein the means for calculating comprises means for adding the time distance between a positive correlation peak and a reference time instance to the time distance between the positive correlation peak and a negative correlation peak.

30. The apparatus of claim 23, wherein the means for calculating comprises means for adding the time distance between a negative correlation peak and a reference time instance.

31. The apparatus of claim 23 wherein the means for extracting comprises:

means for determining a demodulation frame boundary based on the timing offset;

means for determining a demodulation type based on a demodulation type indicator;

means for determining a data signal pulse position using the demodulation frame boundary and the demodulation type; and

means for calculating an output data symbol based on the data signal pulse position.