Browse Prior Art Database

Single Channel Pulse Code Modulation Copier

IP.com Disclosure Number: IPCOM000084831D
Original Publication Date: 1976-Jan-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Marijon, JL: AUTHOR

Abstract

In the coder shown on the drawing, only one reference signal covering the whole coding dynamic is used to transform into a Pulse Code Modulation (PCM) signal the values of N consecutive samples of an analog input signal.

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Single Channel Pulse Code Modulation Copier

In the coder shown on the drawing, only one reference signal covering the whole coding dynamic is used to transform into a Pulse Code Modulation (PCM) signal the values of N consecutive samples of an analog input signal.

The analog signal I to be converted is fed to sampling circuit 1. wherein samples of the signal are taken at a frequency F under control of logic circuit 2 providing a sampling control signal on its output line 3.

When N samples are available in circuit 1, circuit 2 provides on its output line 4 a buffering control signal which causes the N samples to be transferred into analog buffer 5 having N stages 5-1 to 5-N.

As the N samples are buffered, a converting control signal provided by circuit 2 on its output line 6 sets quantizing level generator 7 and counter 8 counting at frequency F. Circuit 7 generates a signal R representing the coding law and covers the whole coding dynamic in a time equal to N/F.

The coded value of a sample is given by counting pulses of frequency F during the time required for signal R to reach the level of the sample to be coded.

Comparators 9-1 to 9-N generate a write control pulse when signal R reaches the levels of input samples in stages 5-1 to 5-N to which they are connected. Write control pulses cause the counting value of counter 8 to be written in registers 10-1 to 10-N.

Assuming signal I represented on the drawing is to be coded, the first coded sample is sample S7, the...