公开(公告)号：GB1271753A

公开(公告)日：1972-04-26

申请号：GB4092669

申请日：1969-08-15

Applicant: IBM

Inventor： CROISIER ALAIN ,  NUSSBAUMER HENRI JEAN

IPC: H04M11/06 ,  H04L25/48 ,  H04L25/497 ,  H04M11/00

Abstract: 1,271,753. Digital transmission systems. INTERNATIONAL BUSINESS MACHINES CORP. 15 Aug., 1969 [4 Sept., 1968], No. 40926/69. Addition to 1,154,648. Heading H4P. In a digital transmission system each digital pulse, of duration T, is represented by a pulse sequence comprising a main pulse with two " echo " pulses following and preceding it. Successive sequences overlap, and the system is so designed that the resulting sequence is a signal (Sin (#t/2D).Cos 2#ft)/t, where T=pD (p is integral), and f=(2n-1)/4D. At the receiver this signal is demodulated with a frequency f+1/4D, the demodulated signal being sampled at a rate 1/T. The main pulses may be multi-level signals. In an example in which n = 2 and p = 1, binary data is passed to a 3-bit shift register stepped at bit rate. The parallel output of the register is selectively passed via gates, enabled by three bit-rate time-staggered clock trains, to a circuit which weights its inputs and presents a signal which, after low-pass filtering, has the waveform defined above.

公开(公告)号：DE1901937A1

公开(公告)日：1969-09-11

申请号：DE1901937

申请日：1969-01-16

Applicant: IBM

Inventor： CROISIER ALAIN

IPC: H04B17/40

公开(公告)号：FR1527135A

公开(公告)日：1968-05-31

申请号：FR06008463

申请日：1967-04-18

Applicant: IBM FRANCE

Inventor： CROISIER ALAIN ,  FALCOZ ALAIN

IPC: G06F13/368 ,  G06F13/42 ,  H04J3/24 ,  H04L12/40