Tuning system and method in broadcast signal receiver

A tuning method comprising:

• transmitting an inverted 8 VSB digital broadcast signal in an idle space of an NTSC (National Television System Committee) spectrum between upper and lower normal NTSC broadcast signals of a high frequency band;
• transferring the upper NTSC broadcast signal to the lower side of said NTSC spectrum;
• transferring the lower NTSC broadcast signal to the upper side of said ntsc spectrum;
• inverting the transferred upper and lower NTSC broadcast signals
• changing the inverted state of the 8 VSB digital broadcast signal into a normal state;
• and
• attenuating the inverted upper and lower NTSC broadcast signals to a predetermined band;
• amplifying the normal 8 VSB digital broadcast signal into said predetermined band;
• and
• lowering the frequency of the amplified 8 VSB digital broadcast signal to a predetermined frequency band.

A tuning system receiving NTSC (National Television System Committee) broadcast signals of a high frequency band NTSC spectrum including an inverted 8 level vestigial side band (8 VSB) digital broadcast signal in the idle space between normal upper and lower NTSC broadcast signals characterized in that an 8 VSB pilot tone is separated from a center frequency of a luminance signal in said upper NTSC broadcast signal by 1.56 MHz, said tuning system comprising:

• a first mixer for mixing a first predetermined oscillation frequency with said inverted 8 level vestigial side band (8 VSB) digital broadcast signal to changing a state of the 8 VSB digital broadcast signal into a normal NTSC spectrum state, transfer the upper NTSC broadcast signal to a lower side of said NTSC spectrum, transfer and the lower NTSC broadcast signal to an upper side of said NTSC spectrum and invert the transferred upper and lower NTSC broadcast signals;
• 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 said 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.