Computer graphics processing and selective visual display system – Display driving control circuitry – Controlling the condition of display elements
Patent
1994-09-28
1996-07-09
Chin, Stephen
Computer graphics processing and selective visual display system
Display driving control circuitry
Controlling the condition of display elements
345264, 345324, 360 29, 329304, 332103, 358323, H04L 512
Patent
active
055352456
ABSTRACT:
A modulation circuit for a digital signal recorder includes first and second high-pass filters for removing the direct current component in the output of the coded I and Q channels and for converting a 4-levels signal into a 7-levels signal. Additionally, a carrier signal generator for generating a carrier signal, a modulator for performing quadrature amplitude and phase modulations on the outputs of first and second high-pass filters using the carrier signal, a pilot signal generator for generating a pilot signal and combining the pilot signal with the output of modulator and for outputting the result for transmission or recording are also provided. A complimentary demodulation circuit includes a carrier restoring circuit for restoring the carrier signal using the pilot signal from the reproduced or received modulated digital signal which has been transferred or recorded, a demodulator for performing quadrature amplitude and phase demodulation on the modulated digital signal using the restored carrier signal to thereby output I and Q channel signals, first and second detectors for detecting the 7-levels digital signal from the output of the demodulator, third and fourth detectors for converting the 7-levels digital signal of the first and second detectors into 4-levels digital signal, and a fifth detector for decoding the outputs of third and fourth detectors to receive the source signal. It will be appreciated that this circuit enhances the accuracy in restoring the carrier and improves the power efficiency.
REFERENCES:
patent: 4123710 (1978-10-01), Stuart et al.
patent: 4355397 (1982-10-01), Stuart
patent: 4945549 (1990-07-01), Simon et al.
patent: 4979052 (1990-12-01), Matsuta et al.
patent: 5062007 (1991-10-01), Nakatsu et al.
patent: 5095392 (1992-03-01), Shimazaki et al.
patent: 5402242 (1995-03-01), Nakatsu et al.
Chin Stephen
Ghebretinsae T.
Samsung Electronics Co,. Ltd.
LandOfFree
Modulation/demodulation circuit for a digital signal recorder/re does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Modulation/demodulation circuit for a digital signal recorder/re, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Modulation/demodulation circuit for a digital signal recorder/re will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1874356