DIGITAL TV ON CHANNEL REPEATER WITH DIGITAL ADAPTIVE CORRECTION

摘要

A DTV(Digital TV) same channel repeater having a digital distortion compensation function is provided to transmit a high-quality signal having a high S/N(Signal to Noise) value and reduce a signal delay time generated until a signal is retransmitted after the signal is received. A signal processing unit(5) is additionally installed between a DTV RF(Radio Frequency) receiver(4) and a DTV RF transmitter(6). The signal processing unit has an A/D(Analog to Digital) converting unit(53), an I/Q(Inphase/Quadrature) demodulating unit(54), an adaptive compensation unit(58), a digital filter unit(55), an I/Q modulating unit(56), and a D/A(Digital to Analog) converting unit(57). The A/D converting unit converts an IF(Intermediate Frequency) signal inputted from an IF BPF(Band Pass Filter)(44) into a digital signal. The I/Q demodulating unit demodulates a digital IF signal outputted from the A/D converting unit into a baseband signal. The adaptive compensation unit demodulates a transmission signal outputted from the DTV RF transmitter, calculates a filter coefficient of the digital filter unit, and generates an LUT(Look-Up Table). The digital filter unit corrects a channel characteristic from the output signal of the I/Q demodulating unit under the control of the adaptive compensating unit, removes an error, and compensates linear and non-linear distortion components of a transmission-end HPA(High Power Amplifier)(62). The I/Q modulating unit modulates the signal corrected in the digital filter unit. The D/A converting unit converts the digital signal modulated in the I/Q modulating unit into an analog IF signal.