GB610464A - Electric pulse communication systems - Google Patents

Abstract

610,464. Multiplex pulse signalling. STANDARD TELEPHONES & CABLES, Ltd. April 6, 1946, No. 10664. Convention date, Aug. 25, 1944. [Class 40 (v)] In a pulse multichannel communication system, spaced segments from the signals of a number of channels are interleaved together and used to time modulate the transmitted pulses. In one embodiment, a base pulse producer 4 feeds pulses at the repetition frequency of each individual channel through a pulse shaper 8 to a delay line 10 to deblock each channel amplifier 12 in turn, thus producing spaced pulses of amplitude corresponding to the instantaneous signal value of each channel. Unmodulated pulses at the repetition frequency of the system as a whole are fed to phase modulator 19 by a pulse multiplier 6 controlled by pulse producer 4. The output pulses from 19, modulated in accordance with amplitudes of the signal sectments from amplifiers 12, are fed to a clipper mixer 21 together with synchronizing pulses from shaper 8 or a separate pulse shaper 8a. The output of mixer 21 modulates a transmitter 23. The time modulator, Fig. 3 (not shown), may be of the type in which the unmodulated pulses and the signal segments are fed to a delay network including a cored coil, the inductance of which varies with the amplitude of the signal pulses, to delay the channel pulses by varying amounts. The synchronizing pulses are distinguished from the signal channel pulses by width. In a modification, Fig. 4 (not shown), pulses at the repetition frequency of the system as a whole are fed through a pulse divider to provide synchronizing pulses and deblocking pulses for the channel amplifiers. The pulses also control a wave producer, the triangular wave output of which is fed to a gate clipper together with the signal segments to provide width modulated pulses, which are differentiated and clipped. The resulting phase modulated pulses are mixed with the synchronizing pulses, and clipped to provide pulses for modulating the transmitter.