Patent ID: 6724441
Filing Date: 2004-04-20
Classification: H03D,H04L,H04N

Abstract:
A tuning system comprising:a first mixer for mixing a first predetermined oscillation frequency with an inverted 8 level vestigial side band (8 VSB) digital broadcast signal in the idle space between normal upper and lower NTSC (National Television System Committee) broadcast signals of a high frequency band received from a transmitter, transferring the upper NTSC broadcast signal to a lower side of an NTSC spectrum and the lower NTSC broadcast signal to an upper side of said NTSC spectrum, inverting the transferred NTSC broadcast signals, and changing a state of the 8 VSB digital broadcast signal into a normal NTSC spectrum state; a filter for attenuating the inverted upper and lower NTSC broadcast signals output from the first mixer to a predetermined band and amplifying the normal 8 VSB digital broadcast signal into the predetermined band; and a second mixer for mixing a second predetermined oscillation frequency with the attenuated NTSC broadcast signals and the amplified 8 VSB digital broadcast signal output from the filter and lowering the frequency of the mixed signal to a predetermined frequency band.