Detection and bypass of tandem vocoding using detection codes

Details Detection and bypass of tandem vocoding using detection codes Detection and bypass of tandem vocoding using detection codes

1995-01-25

1999-09-21

Hudspeth, David R.

Data processing: speech signal processing, linguistics, language

Speech signal processing

For storage or transmission

704212, 704228, 455436, G10L 918, H04Q 724

Patent

active

059566736

ABSTRACT:
A first remote vocoder receives analog voice and produces packetized vocoder data which is transmitted over a wireless link. A first local vocoder receives the packetized vocoder data from the wireless link. The first local vocoder converts the packetized data to a multibit PCM output. The first local vocoder also adds a detection code to one of the least significant bits (LSB) of the PCM output. The first local vocoder passes the PCM signal to the PSTN from the second end user. The first local vocoder also receives PCM input over the PSTN. The first local vocoder constantly monitors the least significant bit of the PCM input for a detection code indicating that a second local vocoder is connected at the receiving end. If the first local vocoder detects the detection code from the second local vocoder, it begins to substitute packetized data and a redundancy check for a second one of the LSB's of the outgoing PCM. The first local vocoder also begins to monitor the second one of the LSB's of the incoming PCM. If the redundancy check indicates that valid packetized data has been received, the first local vocoder stops converting the PCM output into packetized data and simply passes the packetized data on the second one of the LSB's to the first remote vocoder. If at any time the redundancy check fails and the detection code is not detected, the first local vocoder returns to converting the incoming PCM to packetized data. In this way, the tandem vocoding arrangement is avoided.

REFERENCES:
patent: 4782326 (1988-11-01), Bush
patent: 4802206 (1989-01-01), Yoshida et al.
patent: 5317567 (1994-05-01), Champion
patent: 5515397 (1996-05-01), Wiorek
patent: 5608779 (1997-03-01), Lev et al.
Elis D. Hanson, "Intelligibility Testing Of The Continuous Variable Slope Delta (CVSD) Coder-Decoder (CODEC)", Research and Development Technical Report ECOM-3393, AD 721586, XP 000573297, Feb. 1971, 23 pages.

Affiliated with

Also associated with

Rating

Detection and bypass of tandem vocoding using detection codes does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Detection and bypass of tandem vocoding using detection codes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection and bypass of tandem vocoding using detection codes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-91393