Browse Prior Art Database

Multispeed, Multipurpose Multiplexer

IP.com Disclosure Number: IPCOM000090958D
Original Publication Date: 1969-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Frei, AH: AUTHOR [+2]

Abstract

This system uses a delta-modulation method which differs from conventional delta-modulation in that an information bit is generated whenever the source signal exceeds a predetermined level. This produces a type of asynchronous operation within the modulators. Synchronization occurs only at the multiplexer location to simplify the timing problem.

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Multispeed, Multipurpose Multiplexer

This system uses a delta-modulation method which differs from conventional delta-modulation in that an information bit is generated whenever the source signal exceeds a predetermined level. This produces a type of asynchronous operation within the modulators. Synchronization occurs only at the multiplexer location to simplify the timing problem.

In the drawing which shows one modulator, several sources 1...2/N/-1 are each connected to one modulator. The sources can supply analog or digital signals of different bandwidth. All modulators are combined within a scanner and multiplexer circuit. When the input signal of one source differs significantly from the reconstructed signal as it is determined by a variable deadband slicer, the modulator sends a Request signal to the scanner and multiplexer circuit. When the scanner has a time slot free, it sends an Enable pulse to this modulator which causes the information bit to be sent to the scanner. The scanner in turn sends the sign bit plus the address bits over the channel.

The scanning of the modulators is done in a sequential manner. The scanner is arranged so that a time slot on the channel never goes empty if any one of the sources has information to be transmitted. If two or more sources simultaneously have information to transmit, the information of one source is transmitted at one time instant. The information bits of the other sources are stored for a certain time within the...