The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 23, 1992
Filed:
Aug. 10, 1990
Hitosi Matui, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a digital data transmission device for transmitting a composite transmission signal comprising a main data signal represented by parallel n bits and a subdata signal, a multilevel encoding unit encodes upper and lower levels of m bits in the main data signal into first and second encoded signals. A first signal converter converts the first and the second encoded signals and an uncoded signal of (n-m) bits in the main data signal to a first converted signal. An inverter inverts the first encoded signal to an inverted signal. A second signal converter converts the inverted signal, the second encoded signal, and the uncoded signal to a second converted signal. A selection unit selects a selected signal from the first and the second converted signals in response to the subdata signal and produces the selected signal as the composite transmission signal. A digital data reception device receives as a reception signal the composite transmission signal produced by the digital data transmission device and comprises a processing unit for processing the reception signal to produce a processed signal and a reproducing unit. Supplied with the processed signal, the reproducing unit reproduces the main data signal and the subdata signal as a reproduced main data signal and a reproduced subdata signal.