Device for the realization of the hands free function in a telephone set associated with the functions of gain switching and echo cancelling

摘要

device for the realization of the function u00adlibres hands in a telephone set with the functions of gain switching and echo cancellation.;the device is characterized in that it comprises a gain switch and a method of echo cancellation, the switch (20) includes in the routes of transmission and reception means (10, 11) for measurement of amplitude of the signals present on the tracks, a circuit (12) for the determination of the state of the telephone set, sending, receiving, rest).a body (13) controlled by the calculation circuit (12), the variable attenuators (14, 15) controlled by the body (13), the body design calculation based on evaluating amplitudes for transmission and reception of the signals, the performance of echo cancellation is obtained by the adjusting device and as a function of the attenuators (14, 15) in each channel.in such a way that the overall reduction in the loop is always the minimum value for the stability of the system.;application by telephone.