DEVICE FOR TREATING SPEECH SIGNALS FOR A RADIO-ELECTRICAL TRANSMIT-RECEIVE EQUIPMENT ADAPTED FOR TRANSMISSION AND RECEPTION OF SPEECH SIGNALS

摘要

1. Speech processing device (1) for a radioelectric transmitter-receiver equipment, adapted for the transmission and the reception of speech, of the type comprising a circuit (11) for the compression of the volume range of the speech signal to maintain almost constant the modulation level of the speech during the transmission of the speech, and an expander (18) for restoring upon reception the speech level prior to its compression, as well as a device (17) for controlling the expander which is sensitive to the value of the attenuation introduced by the compression circuit (11) and transmitted on a radioelectric auxiliary frequency channel of the equipment, characterized in that the compression circuit (11) is an incremental compression circuit acting with anticipation in time and comprising a delay line (14) connected to a first variable attenuator (15) to delay the speech signal and to attenuate it prior to its transmission, as well as a second variable speech signal attenuator (16), and in that the device further comprises a logic filter circuit (13) for the level of the speech upon transmission coupled to the second variable attenuator (16) to control the first and second attenuators of the compression circuit (11) with constant attenuation steps, in a manner to maintain almost constant the level of speech upon transmission and to transmit the corresponding incremental attenuation values on the auxiliary channel, and in that the control device (17) of the expander (18) comprises an interpolation circuit (30, 33, 37, 38, 39) to correct the presumption of errors of the received signals which are representative of the attenuation values introduced by the logic filter circuit (13) upon transmission.