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:
Apr. 08, 1980
Filed:
May. 24, 1978
Takashi Hiyama, Tokyo, JP;
Nippon Electric Co., Ltd., Tokyo, JP;
Abstract
A pilot signal transmission system is disclosed in which two terminal stations transmit signals including link monitoring pilot signals to each other directly or through a repeater station. The terminal stations include a pilot signal switching section responsive to a detection signal from a transmitting pilot detecting section for operating in such a manner that if the detection signal is normal it transmits the output of the pilot transmitting section to the transmitting section, while if the detection signal is abnormal it transmits the output of the filtering section to the transmitting section. In the case of a repeater station, up and down pilot switching sections are responsive to detection signals from the receiving pilot detecting sections for operating in such a manner that the pilot signals filtered by the pilot filtering sections may be either transmitted to the transmitting sections or interrupted, the receiving pilot signal being repeatered jointed with the demodulated signal from the receiving section if the detection signal is normal, while the receiving pilot signal for the opposite direction link being repeatered jointly with the demodulated signal from the receiving section if the detection signal is abnormal.