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:
Oct. 23, 1990
Filed:
May. 26, 1989
Shunichiro Tejima, Tokyo, JP;
NEC Corporation, , JP;
Abstract
In a satellite communication system for carrying out communication between a central station and local stations, each local station includes a receiving apparatus (41) which comprises a converting unit (43) for converting a received radio signal of a received carrier frequency into a converted signal by using a reception carrier signal of a reception carrier frequency and a demodulating unit (44) for demodulating the converted signal into a demodulated signal. Connected to the demodulating unit, a deciding unit (45) decides whether the demodulated signal is normal or abnormal. The deciding unit produces an abnormal signal when the demodulated signal is abnormal. After reception of the abnormal signal, a timer circuit (47) measures a lapsed time to produce a time up signal when the lapsed time is equal to an integral multiple of a predetermined time interval. Responsive to the time up signal, a supplying section (49) alternately supplies first and second carrier signals indicative of first and second memorized frequency signal preliminarily memorized in a memorizing section (48), respectively, one at a time as the reception carrier signal to the converting unit.