Binary code signals transmission system

• Main Author: MASAKA OGI
• Format: Patent
• Language: English
• Published: 16.04.1969
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

1,148,805. Digital transmission systems; multiplex pulse code signalling. FUJITSU Ltd. 6 Sept., 1966, No. 39875/66. Headings H4L and H4P. In a digital transmission system phasemodulated signals are transmitted, a frequency discriminator recovering the data at the receiver. In one embodiment return to zero (RZ) data in bipolar or unipolar form is converted to a differentially coded signal which feeds the modulator. By detecting the instantaneous frequency changes in the transmitted signal the discriminator develops a bipolar RZ signal. In a second embodiment the input bipolar RZ data is split between two channels, one carrying a signal representing the positive pulses in differential code and the other a signal representing the negative input pulses in differential code. These two signals phase modulate frequencies 90 degrees apart in phase, the resulting signals being combined to give a four-phase signal for transmission. The receiver discriminator develops a unipolar RZ signal. The input data may be time division multiplex pulse code modulation speech signals. Several systems according to the first embodiment may be combined in a frequency multiplex arrangement.