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:
Aug. 30, 1988
Filed:
Apr. 20, 1987
Petrus J Van Gerwen, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
In DAV (data above voice)-systems an analog speech signal is transmitted in the low-frequency portion of the spectrum of an encoded data signal. When a data signal encoded by the known WAL2 code is used, the high-pass filters, required for the separation of the two signals produce intersymbol interference extending over a large number of bit intervals, requiring complicated equalisers at the receive end for good detection. When encoding the data signal in accordance with the DAV-code, as illustrated in FIG. 2 this drawback is remedied. In addition, this DAV-code is advantageous in that the amplitude fractions, represented by a and b, can basically be chosen at will, allowing the low-frequency content of the code to be affected. When (a; b)=(11/16; 3/16) the encoded data signal can be generated very accurately and in a simple manner.