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. 26, 1999
Filed:
Oct. 21, 1997
Hiroki Tsuda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The present invention refers to a received signal detector for detecting and demodulating a digital modulated signal wherein a signal detection in a short time can be implemented independently of the signal frame length. The wide-band filter is a filter having a pass frequency band set to the frequency range of received signals to be demodulated. The A/D convertor, first power detector and first averaging circuit measure the average power of a signal having passed through the wide-band filter. The threshold setting circuit sets a threshold from the averaged power. The narrow-band filter filters an output signal of the frequency convertor in a narrower frequency band than the pass frequency band of the wide-band filter. The comparator circuit compares the threshold and the average power of a signal taken out from the second averaging circuit and passing through the narrow-band filter and judges whether the received signal is taken out from the wide-band filter.