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:
Mar. 09, 1999
Filed:
May. 27, 1997
Shigeki Maeda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The demodulator of this invention is directed toward improving S/N ratio of the demodulator resulting from increase in the peak value of a received signal due to fading. The demodulator is composed of a roll-off filter (not shown), variable amplifier 16, multiplier 10, compressor 11, variable dynamic range analog/digital converter 12, transversal filter 13, expander 14, tap coefficient control circuit 15, and signal level detector 17. Signal level detector 17 detects the magnitude of waveform distortion from the output of tap coefficient control circuit 15 and controls the gain of variable amplifier 16 and the dynamic range of analog/digital converter 12, thereby reducing nonlinear distortion in multiplier 10 that is caused by increases in the peak value due to waveform distortion.