Browse Prior Art Database

Data Transmission System

IP.com Disclosure Number: IPCOM000097279D
Original Publication Date: 1962-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 85K

Publishing Venue

IBM

Related People

Hopner, E: AUTHOR [+2]

Abstract

(Image Omitted) The system transmits data between transmitter and receiver through a telephone line at a rate of 2400 bauds per second. Binary information is conveyed by the transmitted signal in terms of 180 degrees phase reversals relative to the carrier employed at the transmitter.

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Data Transmission System

(Image Omitted)

The system transmits data between transmitter and receiver through a telephone line at a rate of 2400 bauds per second. Binary information is conveyed by the transmitted signal in terms of 180 degrees phase reversals relative to the carrier employed at the transmitter.

The transmitter has modulator 15 which provides a double sideband signal. This has a carrier component proportional to the D.C. component contained in the data signal. A squared data signal is supplied to data input terminal 10. Such connects to terminals 15a and 15b of modulator 15 through low pass filters 12 and 14. These function to remove all harmonic components above the fundamental from the squared data signal. The output of the modulator is connected to the telephone line through amplifier 21, low pass filter 22, amplifier 23 and impedance matching transformer 24. Filter 22 eliminates any cross modulation products from the transmitted signal.

The receiver comprises frequency doubler 53, amplifier 54, tuned circuits 55 and 56, squaring stage 57 and frequency divider 58.

These regenerate a carrier signal at the receiver from a double sideband, proportional carrier signal as received. The receiver also includes high pass filter 60 for eliminating the lower sideband component and any carrier component present in the received signal. Demodulator 62 synchronously demodulates the upper sideband signal from filter 60 with a regenerated carrier signal to recov...