NARROW BAND TRANSMISSION SYSTEM OF DIGITAL SIGNAL

摘要

PURPOSE:To decrease the effect of delay in applying band limit to a transmission band through the use of a filter circuit by sampling and quantizing a signal to be transmitted and outputting the result as a step wave via a DA converter. CONSTITUTION:When a control program signal is inputted to an input terminal 8, a data fetch circuit 9 outputs an NRZ signal to a waveform discriminating circuit 13 in a prescribed timing. The waveform discriminating circuit 13 applies biphase mark modulation to the NRZ signal so as to discriminate the waveform. Address designation is conducted by a ROM14 according to the value of the waveform discriminating signal, a digital data is read and fed to the DA converter 16. The DA converter 16 outputs a step wave to a low-order low pass filter 17.