초록 ▼

A television receiver having two-way telephone capability includes a digitized talk channel and a digitized listen channel each having a gain-controlled amplifier selectively controlled by a switch controlled generator driven by the output of a subtraction circuit. Multipliers are connected to the i

A television receiver having two-way telephone capability includes a digitized talk channel and a digitized listen channel each having a gain-controlled amplifier selectively controlled by a switch controlled generator driven by the output of a subtraction circuit. Multipliers are connected to the inputs of the subtraction circuit and in turn receive respective inputs from their associated channels and from the other channels for offsetting cross coupled signals due to the telephone interface.

대표청구항 ▼

A television receiver having two-way telephone communication capability comprising: a talk channel and a listen channel coupled to a telephone line, said telephone line introducing substantial cross coupling between said channels; an A/D converter in each said channel for digitizing signals in said

A television receiver having two-way telephone communication capability comprising: a talk channel and a listen channel coupled to a telephone line, said telephone line introducing substantial cross coupling between said channels; an A/D converter in each said channel for digitizing signals in said channels; a gain controlled amplifier in each said channel; and channel control means for selectively controlling the gains of said channel as a function of the difference in signal levels in said channels and for offsetting cross coupled signals in said channels, said channel control means including; differential means comparing the signal levels in the channels and developing an output as a function of the comparison; a switch control generator for adjusting the gains of the channels in accordance with the output of the differential means; and a variable gain amplifier, associated with each channel and having an output coupled to a respective input of the differential means and two inputs, one input being responsive to the signal level in the talk channel and another input being responsive to the signal level in the listen channel.