NOISE REDUCTION TECHNIQUE FOR RECEIVE CVSD VOCODER
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-26
This invention applies to digital audio transmissions that use CVSD for analog to digital conversion. CVSD modulation produces a serial data stream. The data stream that is produced during silence is called "idle- pattern:' When there are slight disruptions in this idle- pattern the recovered audio will be noisy when it should be silent. This invention eliminates the noise that is heard when there should be silence. This is accomplished by letting the minimum value for the "Step-Size" go to zero in the CVSD demodulator.