Multiplex communications – Communication techniques for information carried in plural... – Combining or distributing information via frequency channels
Patent
1995-08-11
1997-08-12
Safourek, Benedict V.
Multiplex communications
Communication techniques for information carried in plural...
Combining or distributing information via frequency channels
375261, 375364, H04L 2734
Patent
active
056573138
ABSTRACT:
A signal transmitting apparatus using orthogonal frequency division multiplexing includes an inverse fast Fourier transform circuit for converting a digital information signal into a first multi-value QAM modulation signal. A guard interval setting circuit is operative for periodically generating a guard interval signal equal to a time segment of the first multi-value QAM modulation signal, and inserting the guard interval signal into the first multi-value QAM modulation signal to convert the first multi-value QAM modulation signal into a second multi-value QAM modulation signal. A clock signal generating circuit is operative for generating a first clock signal which drives the inverse fast Fourier transform circuit, and generating a second dock signal which drives the guard interval setting circuit. The inverse fast Fourier transform circuit includes a device for generating a pilot signal which corresponds to a given-order carrier, and adding the pilot signal to the first multi-value QAM modulation signal. The pilot signal has a predetermined frequency and an angle modulation component which remains constant over a plurality of symbol periods. The pilot signal corresponding to a given integer times its wavelength or a given odd number times its half wavelength is present in a guard interval occupied by the guard interval signal in the second multi-value QAM modulation signal. The pilot signal is continuously present over the guard interval and another interval.
REFERENCES:
patent: 5228062 (1993-07-01), Bingham
patent: 5345440 (1994-09-01), Gledhill et al.
patent: 5444697 (1995-08-01), Leung et al.
Sugiyama Kenji
Takahashi Nobuaki
Takahashi Susumu
Safourek Benedict V.
Victor Company of Japan Ltd.
LandOfFree
Signal transmitting apparatus and signal receiving apparatus usi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Signal transmitting apparatus and signal receiving apparatus usi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Signal transmitting apparatus and signal receiving apparatus usi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-166253