Digital television receiver converting vestigial-sideband signals to double-sideband AM signals before demodulation

摘要

A vestigial-sideband (VSB) signal is converted to a double-sideband amplitude-modulation final intermediate-frequency signal that is subsequently detected to generate a baseband demodulation result. The carrier of this final I-F signal has a carrier offset from zero-frequency, which carrier offset exceeds the highest modulating frequency of the VSB signal and is adjusted to a prescribed carrier offset value. The double-sideband amplitude-modulation final I-F signal is generated by combining the VSB signal with its image.