Adaptive data transmission for a digital in-band modem operating over a voice channel

• US 8,249,865 B2
• Filed: 10/13/2010
• Issued: 08/21/2012
• Est. Priority Date: 11/23/2009
• Status: Expired due to Fees

• Current Assignee: Karma Automotive LLC (Wanxiang Group Corporation)
• Original Assignee: Airbiquity Incorporated
• Inventors: Birmingham, Kiley
• Primary Examiner(s): AZAD, ABUL K
• Application Number:
  US12/904,093
• Publication Number:
  US 20110125488A1
• Time in Patent Office: 678 Days
• Field of Search: 704221-223
• US Class Current: 704/221
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0006 by adapting the transmission format

Abstract

In one example, a mobile device encodes a digital bitstream using a particular set of modulation parameters to generate an audio signal that has different audio tones selected to pass through a vocoder of the mobile device. The particular set of modulation parameters is optimized for a subset of a plurality of vocoding modes without a priori knowledge of which one of the vocoding modes is currently operated by the vocoder. The mobile device conducts transmissions over the wireless telecommunications network through the vocoder using the particular set of modulation parameters, and monitors these transmissions for errors. If the errors reach a threshold, then the vocoder may be using one of the vocoding modes that are not included in the subset for which the particular set of modulation parameters is optimized, and accordingly, the modulation device switches from the particular set of modulation parameters to a different set of modulation parameters.

Claims

1. A memory device encoded with instructions that, if executed, result in:

processing a received digital bitstream using a particular modulation parameter set to generate an audio signal that has different audio tones for different bit values, wherein the audio tones are selected to pass through a wireless voice channel of a wireless telecommunication network unobstructed by a vocoder, wherein the particular modulation parameter set is optimized for a subset of a plurality of vocoding modes without a priori knowledge of which one of the plurality of vocoding modes is currently operated by the vocoder for vocoding the audio signal;

transmitting the generated audio signal over the wireless voice channel of the wireless telecommunications network;

determining whether an amount of errors associated with the transmission over the wireless voice channel reaches a preset threshold according to error detecting performed by a receiver; and

switching from the particular modulation parameter set to a different modulation parameter set in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

2. The memory device of claim 1, wherein the different modulation parameter set is designed for wider compatibility than the particular modulation parameter set, and wherein the different modulation parameter set is non-optimized with said subset of vocoding modes and/or optimized with a different subset of vocoding modes.

3. The memory device of claim 1, wherein the instructions, if executed, result in:

transitioning from encoding using a first symbol type to encoding using a second symbol type having a greater duration than the first symbol type in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

4. The memory device of claim 1, wherein the instructions, if executed, result in:

transitioning from encoding using a first frequency pair to encoding using a second lower frequency pair in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

5. The memory device of claim 1, wherein the instructions, if executed, result in:

encoding into the audio signal a first pattern in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold, wherein the first pattern supplies more waveform information for the receiver to use in identifying a symbol than a second pattern encoded into the audio signal prior to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

6. The memory device of claim 1, wherein the instructions, if executed, result in:

transitioning from encoding using a first symbol type to encoding using a second symbol type having a greater duration than the first symbol type in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold, transitioning from encoding using a first frequency set to encoding using a second different frequency set in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold, and encoding into the audio signal a first pattern, wherein the first pattern supplies more waveform information for the receiver to use in identifying a symbol than a second pattern encoded into the audio signal prior to determining that the amount of errors associated with transmission over the wireless voice channel reached the preset threshold.

7. The memory device of claim 1, wherein the instructions, if executed, result in:

switching from a full-duplex transmission mode to a half-duplex transmission mode in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

8. The memory device of claim 1, wherein at least some of the errors result from the vocoder operating a vocoding mode that is not included in the subset to which the particular modulation parameter set is optimized.

9. The memory device of claim 1, wherein the instructions, if executed, result in:

counting a number of non-acknowledgements, wherein the switching is based on said counting.

10. The memory device of claim 1, wherein the instructions, if executed, result in:

processing signaling generated by a receiving endpoint, wherein the switching is based on said signaling.

11. A method, comprising:

processing a received digital bitstream using a particular modulation parameter set to generate an audio signal that has different audio tones for different bit values, wherein the audio tones are selected to pass through a wireless voice channel of a wireless telecommunication network unobstructed by a vocoder, wherein the particular modulation parameter set is optimized for a subset of a plurality of vocoding modes without a priori knowledge of which one of the plurality of vocoding modes is currently operated by the vocoder for vocoding the audio signal;

transmitting the generated audio signal over the wireless voice channel of the wireless telecommunications network;

feeding back actual error information from a demodulation endpoint for the transmission over the wireless voice channel;

wherein the fed back actual error information represents a result of error detecting performed by the demodulation endpoint; and

switching from the particular modulation parameter set to a different modulation parameter set when the fed back error information indicates errors reaching a preset threshold.

12. The method of claim 11, wherein the different modulation parameter set is non-optimized with said subset of vocoding modes and/or optimized with a different subset of vocoding modes.

13. The method of claim 11, further comprising:

transitioning from encoding using a first symbol type to encoding using a second symbol type having a greater duration than the first symbol type when the fed back error information indicates errors reaching the preset threshold.

14. The method of claim 11, further comprising:

transitioning from encoding using a first frequency set to encoding using a second lower frequency set when the fed back error information indicates errors reaching a preset threshold.

15. The method of claim 11, further comprising:

encoding into the audio signal a first pattern, wherein the first pattern supplies more waveform information for the receiver to use in identifying a symbol than a second pattern encoded into the audio signal before the preset threshold is reached.

16. A memory device encoded with instructions that, if executed, result in:

determining whether a vocoder is currently operating a particular one or ones of a plurality of vocoding modes;

processing a received digital bitstream using a particular modulation parameter set to generate an audio signal that has different audio tones for different bit values, wherein the audio tones are selected to pass through a wireless voice channel of a wireless telecommunication network unobstructed by the vocoder;

wherein if the determination indicates that the vocoder is currently operating the particular one or ones of the plurality of vocoding modes, the particular modulation parameter set has a first set of parameters, and wherein otherwise the particular modulation parameter set has a second different set of parameters;

transmitting the generated audio signal over the wireless voice channel of the wireless telecommunications network;

determining whether an amount of errors associated with the transmission over the wireless voice channel reaches a preset threshold according to error detecting performed by a receiver; and

adapting processing of the received digital bitstream in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

17. The memory device of claim 16, wherein the instructions, if executed, result in:

transitioning from encoding using a first symbol type to encoding using a second symbol type having a greater duration than the first symbol type in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

18. The memory device of claim 16, wherein the instructions, if executed, result in:

transitioning from encoding using a first frequency set to encoding using a second lower frequency set in response to determining that the amount of errors associated with the transmission over the wireless voice channel reached the preset threshold.

19. The memory device of claim 16, wherein the instructions, if executed, result in:

encoding into the audio signal a first pattern in response to determining that the amount of errors associated with transmission over the wireless voice channel reached the preset threshold, wherein the first pattern supplies more waveform information for the receiver to use in identifying a symbol than a second pattern encoded into the audio signal prior to determining that the amount of errors associated with transmission over the wireless voice channel reached the preset threshold.

20. The memory device of claim 16, wherein the instructions, if executed, result in:

counting a number of non-acknowledgements or processing signaling generated by a receiving endpoint, wherein the adapting is based on said counting or said signaling.