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:
May. 09, 1989
Filed:
Jul. 10, 1987
Yoshizo Shibano, Osaka, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A modem system is disclosed which has improved reliability of detection of transmitted PSK data using a simple signal delay detection scheme. A transmission signal is produced in which repetitive digital time slots each contain phase encoded 'mark' or 'space' data. Each time slot includes a reference phase portion at at least one of a front and rear portion of the tome slot. The phase of the transmitted signal changes in the remaining portion of each time slot in accordance with applied digital data. For a 'mark' data signal the phase changes from a reference phase in a first direction to predetermined phase in a first half of the remaining portion of the time slot, and then back to the reference phase before the end of the time slot. For a 'space' data signal the phase changes from the reference value in a second direction opposite the first to another predetermined value in a first half of the remaining portion of the time slot, and then back to the reference phase before the end of the time slot. A simple delay detection demodulation system is used to recreate the original digital signal.