Browse Prior Art Database

Automatic Control of Receiver Bit Rate and Timing in Modems by the Transmitter

IP.com Disclosure Number: IPCOM000095626D
Original Publication Date: 1964-Mar-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Liberman, RA: AUTHOR [+2]

Abstract

The above modem (modulation-demodulation) system permits remote control of the binary data resampling rate of a receiver. It is sometimes required to transmit binary data at different rates for different lengths of time. When a change in rate is made, it is necessary to change the receiver resampling rate. This modem system permits a transmitter to remotely control the resampling rate at the receiver. Such control is by tagging the front of the binary message with an M-sequence which selects the data resampling rate at the receiver.

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Automatic Control of Receiver Bit Rate and Timing in Modems by the Transmitter

The above modem (modulation-demodulation) system permits remote control of the binary data resampling rate of a receiver. It is sometimes required to transmit binary data at different rates for different lengths of time. When a change in rate is made, it is necessary to change the receiver resampling rate. This modem system permits a transmitter to remotely control the resampling rate at the receiver. Such control is by tagging the front of the binary message with an M-sequence which selects the data resampling rate at the receiver.

In the transmitter, the Control Center, whether operated by hand or by program control, simultaneously stops the bit timing supplied to the data source, inhibits gate G1 to block information emitted from the data source, and conditions gate G2 to pass a binary sequence from the Sequence Generator. The latter, which is operated at 300 bits p second when emitting data, generates an M- sequence of specified length and configuration. The number of times the sequence is generated and passed to the Modulator for transmission indicates the new rate at which the data is to be transmitted. For example, a series c six M-sequences can represent a data rate of 1200 bits per second fc the message following the sequence.

At the receiver, each M-sequence of the series is detected by the Sequence Detector which emits a pulse for each sequence. The resulting series of pulse...