ADAPTIVE DATA TRANSMISSION FOR A DIGITAL IN-BAND MODEM OPERATING OVER A VOICE CHANNEL

• US 20110125488A1
• Filed: 10/13/2010
• Published: 05/26/2011
• Est. Priority Date: 11/23/2009
• Status: Active Grant

• Current Assignee: Karma Automotive LLC (Wanxiang Group Corporation)
• Original Assignee: Airbiquity Incorporated
• Inventors: Birmingham, Kiley
• Granted Patent: US 8,249,865 B2
• Time in Patent Office: Days
• US Class Current: 704/201
• 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 processor readable medium 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;

monitoring transmissions over the wireless telecommunications network to identify when an amount of errors associated with transmission over the wireless voice channel reaches a preset threshold; and

if the monitoring indicates the error amount reaching the preset threshold, switching from the particular modulation parameter set to a different modulation parameter set.

2. The processor readable medium 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 processor readable medium of claim 1, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, transitioning from encoding using a first symbol type to encoding using a second symbol type having a greater duration than the first symbol type.

4. The processor readable medium of claim 1, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, transitioning from encoding using a first frequency pair to encoding using a second lower frequency pair;

wherein the first higher frequency pair is used with the erroneous transmissions.

5. The processor readable medium of claim 1, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, 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 erroneous transmission is identified.

6. The processor readable medium of claim 1, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, transitioning from encoding using a first symbol type to encoding using a second symbol type having a greater duration than the first symbol type, transitioning from encoding using a first frequency set to encoding using a second different frequency set, 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 before the erroneous transmission is identified.

7. The processor readable medium of claim 1, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, switching from a full-duplex transmission mode to a half-duplex transmission mode.

8. The processor readable medium 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 in association with the erroneous transmission.

9. The processor readable medium 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 processor readable medium 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 a 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;

feeding back actual error information from a demodulation endpoint for the transmissions; 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;

wherein the first higher frequency set is used with the erroneous transmissions.

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 processor readable medium 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 a 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 a 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;

monitoring transmissions over the wireless telecommunications network to identify when an amount of errors associated with transmission over the wireless voice channel reaches a preset threshold;

if the monitoring indicates the error amount reaching the preset threshold, adapting processing of the received digital bit stream.

17. The processor readable medium of claim 16, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, transitioning from encoding using a first symbol type to encoding using a second symbol type having a greater duration than the first symbol type.

18. The processor readable medium of claim 16, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, transitioning from encoding using a first frequency set to encoding using a second lower frequency set.

19. The processor readable medium of claim 16, wherein the instructions, if executed, result in:

if the monitoring indicates the error amount reaching the preset threshold, 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 bit length encoded into the audio signal before the erroneous transmission is identified.

20. The processor readable medium 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.