Nippon Telegraph and Telephone Corporation

Nippon Telegraph and Telephone Public Corporation

Hideo Kishimoto

Makoto Yoshitoshi

Masaaki Terai

Kazumi Kato

Keizo Sugita

Isao Kawashima

A digital code decoding apparatus including a reference waveform storage section which prestores, as reference waveforms, at least m received waveforms corresponding to m possible values of m-value digital codes distorted during transmission, a waveform comparing section which compares at least m reference waveforms read out of the reference waveform storage section and the received waveform, respectively, and a decoded information output section which discriminates one of the reference waveforms which most resembles the received waveform, on the basis of the compared outputs from the waveform comparing section, and outputs, as decoded information, a digital code corresponding to the discriminated reference waveform.

Digital code decoding apparatus

There are provided a current detecting resistance element connected in series with a loop for supplying current to a telephone set, a switching circuit including a three terminal semiconductor switching element connected to be ON.OFF controlled by the voltage drop across the resistance element, and an impedance element controlled by the ON.OFF operation of the switching element to be connected across the loop for adding AC loss.

Automatic signal level adjusting circuits for use in telephone sets

Growing community of inventors

Yokohama, Japan

Hideo Kishimoto