Browse Prior Art Database

Voice Data System

IP.com Disclosure Number: IPCOM000095641D
Original Publication Date: 1964-Apr-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Puente, JG: AUTHOR

Abstract

This system transmits voice and data simultaneously over the same band width transmission channel. Transmitter 10 comprises modulator 12 and summing network 14. Summer 14 combines the modulated data signal with the voice in a linear fashion and provides it to transmission channel 16.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 83% of the total text.

Page 1 of 2

Voice Data System

This system transmits voice and data simultaneously over the same band width transmission channel. Transmitter 10 comprises modulator 12 and summing network 14. Summer 14 combines the modulated data signal with the voice in a linear fashion and provides it to transmission channel 16.

Receiver 20 has an AGC circuit 22 which feeds into band pass filter 24 and delay circuit 26. Filter 24 passes only the spectrum occupied by the data signals and applies it to carrier recovery circuit 28. This reproduces the carrier used to modulate the data at the transmitter. The carrier is also used to demodulate the received data signals in demodulator 30. Its output is fed to low pass filter 32 and squaring circuit 34. This generates the recovered data signal.

To recover the voice signal, the squarer 34 output is applied to modulator 36. A data signal uncontaminated by voice signals is fed through band pass filter 38 to subtract circuit 40. Here a separation occurs between the pure data signal generated at the transmitter and the delayed version of the composite voice-data signal received over transmission channel 16.

The operation of the system depends upon the recognition that when voice and data signals occupy the entire, e.g., 3KCPS spectrum, of the transmission channel, there is nevertheless a portion which is occupied predominantly by voice, and a portion predominantly occupied by data. For the data recovery circuits, the attendant voice signals can be tre...