DIGITAL FREQUENCY-TRANSLATED, PLURAL-CHANNEL VESTIGIAL SIDEBAND TELEVISION COMMUNICATION SYSTEM

摘要

ABSTRACT OF THE DISCLOSUREA television communication system distributes pluralVSB digitally encoded TV channels via an optical transmissionlink to one or more distribution terminals. At the head-end thefrequency band of each of the VSB signals is shifted down tobaseband and transmitted in digital format. At each stationalong the network, the digitized baseband VSB television signalis converted into analog format and then reshifted through anup-converter to its original IF band so as to be compatible withthe television receiver circuitry of the subscribers served bythe distribution station. Advantageously, the present inventionmay employ optical communication techniques for coupling thedigitally encoded frequency-shifted VSB television signalsbetween stations. To maintain signal strength and quality,repeater units may be located in the optical communication link.Each repeater converts an incoming optical signal to anelectrical signal for amplification and then reconverts theimproved electrical signal back into optical form for furthertransmission along the link.