Waveform correction by sampling
OwnerCharles B. Fisher, Sidney T. Fisherinventors
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Abstract
A system which automatically corrects the wave-form of a signal of a given frequency passing over a transmission path, over which a carrier double-sideband amplitude-modulated by a complex tone and extending across the given signal-frequency band is transmitted in the signal-frequency band as a combined wave with the signal. At the receiving apparatus the reconstructed modulated carrier is used as a standard to correct the waveform of the signal from distortion caused by the transmission path, using sampling, reconstruction, comparison and gain-variation methods. The modulated carrier is eliminated from the corrected signal at the output of the receiving apparatus by sampling and reconstruction methods. Sampling and modulation frequencies and phases are derived from the carrier.
Claims2
A continuous automatic waveform correction system, comprising transmitting apparatus which combines a signal with a periodic pilot extending substantially across the frequency band of said signal, and receiving apparatus which requires said combined signal with waveform distortion, and substantially corrects said waveform distortion in variable gain means, adjusted in gain by comparison means which compares said pilot as received and separated by subtraction means from said signal, with a pilot generated in said receiving apparatus from the carrier of said pilot transmitted from said transmitting apparatus, and pilot elimination means which substantially eliminates said pilot from said signal after said waveform distortion correction in said signal after said waveform distortion correction in said variable gain means, and delivers said signal substantially free from said waveform distortion and from said pilot to an external circuit.
Dependencies are inferred from the claim text.