Sidetone level reduction circuit and method
AssigneeVTech Communications, Ltd.
InventorStephen George Kropp
Life of this patent
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Abstract
A sidetone level reduction circuit for reducing the sidetone level in digital cordless telephones incorporating continuously variable slope delta modulator/demodulator (CVSD) digital to analog technology is disclosed comprising a CVSD encoder for converting an analog voice signal to a digital signal, a CVSD decoder for converting a digital signal to an analog signal voice signal, and coupling means connecting the coincidence output of the CVSD encoder and the coincidence output of the CVSD decoder in a manner such that the coincidence output of the CVSD decoder can affect the CVSD encoder but the CVSD encoder cannot affect the CVSD decoder.
Claims3
A sidetone level reduction circuit for reducing the sidetone level in digital cordless telephones incorporating continuously variable slope delta modulator/demodulator (CVSD) digital to analog technology, said sidetone level reduction circuit comprising:
- a CVSD encoder for converting an analog signal to a digital signal for transmission from the baseset unit to the handset unit, the CVSD encoder having a coincidence output;
- a CVSD decoder for converting a digital signal received from the handset unit to an analog signal voice signal, the CVSD decoder having a coincidence output;
- and
- coupling means connected in series between the coincidence output of the CVSD encoder and the coincidence output of the CVSD decoder in a manner such that the coincidence output of the CVSD decoder can affect the CVSD encoder but the CVSD encoder cannot affect the CVSD decoder.
A method for reducing sidetone level in digital cordless telephones incorporating continuously variable slope delta modulator/demodulator (CVSD) digital to analog technology, said sidetone level reduction method comprising:
- supplying a CVSD encoder for converting an analog signal to a digital signal for transmission from the baseset unit to the handset unit, the CVSD encoder having a coincidence output;
- supplying a CVSD decoder for converting a digital signal received from the handset unit to an analog signal voice signal, the CVSD decoder having a coincidence output;
- and
- coupling the coincidence output of the CVSD encoder and the coincidence output of the CVSD decoder in a manner such that the coincidence output of the CVSD decoder can affect the CVSD encoder but the CVSD encoder cannot affect the CVSD decoder.
Dependencies are inferred from the claim text.