SYSTEM AND METHOD OF AN IN-BAND MODEM FOR DATA COMMUNICATIONS OVER DIGITAL WIRELESS COMMUNICATION NETWORKS

• US 20090306975A1
• Filed: 06/03/2009
• Published: 12/10/2009
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: WERNER, MARC W., JOETTEN, CHRISTOPH A., PIETSCH, CHRISTIAN, FRANK, GEORG, GRANZOW, WOLFGANG, SGRAJA, CHRISTIAN, HUANG, PENGJUN
• Granted Patent: US 8,725,502 B2
• Time in Patent Office: Days
• US Class Current: 704/214
• 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: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: H04J 3/0611 PN codes H04J3/0608 takes precedence
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation

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 synchronizing non-speech frames through a speech codec comprising:

generating a predetermined sequence that has noise-like characteristics and is robust to speech frame errors; and

sending the predetermined sequence through a speech codec,

wherein the predetermined sequence is used as frame synchronization for the non-speech frames,

wherein the start of the non-speech frame boundaries are not dependent on the start of the speech codec frame boundaries.

2. The method of claim 1 wherein the predetermined sequence is a function of a pseudorandom noise sequence.

3. The method of claim 2 wherein the function is comprised of concatenating a plurality of pseudorandom noise sequences.

4. The method of claim 2 wherein the function is comprised of concatenating a plurality of pseudorandom noise sequences with a plurality of overlapped and added pseudorandom noise sequences.

5. The method of claim 1 wherein each sample of the predetermined sequence is separated by at least one sample of value binary 0.

6. The method of claim 3 wherein at least one of the pseudorandom noise sequences is inverted.

7. The method of claim 1 further comprising generating a wakeup signal prior to the predetermined sequence to prohibit a vocoder encoder element from entering an inactive state.

8. The method of claim 7 wherein the wakeup signal is a sinusoidal signal.

9. The method of claim 7 wherein the inactive state is a discontinuous transmission state.

10. The method of claim 7 wherein the inactive state is the lowest transmission rate in a set of transmission rates.

11. A memory storing a computer program that, when executed, causes a computer to perform the acts of:

generating a predetermined sequence that has noise-like characteristics and is robust to speech frame errors; and

sending the predetermined sequence through a speech codec,

wherein the predetermined sequence is used as frame synchronization for the non-speech frames,

wherein the start of the non-speech frame boundaries are not dependent on the start of the speech codec frame boundaries.

12. An apparatus comprising:

a generator configured to generate a predetermined sequence that has noise-like characteristics and is robust to speech frame errors; and

a speech codec configured to process the predetermined sequence to produce a speech packet,

wherein the predetermined sequence is used as frame synchronization for the non-speech frames,

wherein the start of the non-speech frame boundaries are not dependent on the start of the speech codec frame boundaries.

13. The apparatus of claim 12 wherein the predetermined sequence is a function of a pseudorandom noise sequence.

14. The apparatus of claim 13 wherein the function is comprised of concatenating a plurality of pseudorandom noise sequences.

15. The apparatus of claim 13 wherein the function is comprised of concatenating a plurality of pseudorandom noise sequences with a plurality of overlapped and added pseudorandom noise sequences.

16. The apparatus of claim 12 wherein each sample of the predetermined sequence is separated by at least one sample of value binary 0.

17. The apparatus of claim 14 wherein at least one of the pseudorandom noise sequences is inverted.

18. The apparatus of claim 12, wherein the generator is further configured to generate a wakeup signal prior to the predetermined sequence to prohibit a vocoder encoder element from entering an inactive state.

19. The apparatus of claim 18 wherein the wakeup signal is a sinusoidal signal.

20. The apparatus of claim 18 wherein the inactive state is a discontinuous transmission state.

21. The apparatus of claim 18 wherein the inactive state is the lowest transmission rate in a set of transmission rates.

22. An apparatus comprising:

means for generating a predetermined sequence that has noise-like characteristics and is robust to speech frame errors; and

means for sending the predetermined sequence through a speech codec,

wherein the predetermined sequence is used as frame synchronization for the non-speech frames,

wherein the start of the non-speech frame boundaries are not dependent on the start of the speech codec frame boundaries.

23. The apparatus of claim 22 wherein the predetermined sequence is a function of a pseudorandom noise sequence.

24. The apparatus of claim 23 wherein the function is comprised of concatenating a plurality of pseudorandom noise sequences.

25. The apparatus of claim 23 wherein the function is comprised of concatenating a plurality of pseudorandom noise sequences with a plurality of overlapped and added pseudorandom noise sequences.

26. The apparatus of claim 22 wherein each sample of the predetermined sequence is separated by at least one sample of value binary 0.

27. The apparatus of claim 24 wherein at least one of the pseudorandom noise sequences is inverted.

28. The apparatus of claim 22, wherein the means for generating is further configured to generate a wakeup signal prior to the predetermined sequence to prohibit a vocoder encoder element from entering an inactive state.

29. The apparatus of claim 28 wherein the wakeup signal is a sinusoidal signal.

30. The apparatus of claim 28 wherein the inactive state is a discontinuous transmission state.

31. The apparatus of claim 28 wherein the inactive state is the lowest transmission rate in a set of transmission rates.