AUTOMATIC ALARM SYSTEM OF DIGITAL BROADCASTING SYSTEM AND METHOD FOR THE SAME

摘要

PURPOSE: An automatic alarm system of a digital broadcasting system and a method for the same are provided to generate automatically an alarm signal by sensing non-linear distortion of a broadcasting signal. CONSTITUTION: In a transmitting part(200), a modulator(201) modulates received broadcasting data to an intermediate frequency of 44MHz. An up-converter(202) converts the intermediate frequency of 44MHz to a radio frequency. An intermediate amplifier(203) amplifies the radio frequency. A coupler(205) extracts a part of the amplified radio frequency. The modulator(201) has a look-up table to compensate non-linear distortion of the amplifier(204). In the receiving part(210), a down-converter(212) converts the radio frequency extracted by the coupler(205) to the intermediate frequency. A demodulator(211) demodulates the intermediate frequency and generates a value of amplitude according to the frequency of the converted signal. An alarm signal generator(214) generates an alarm signal by determining the extracted radio frequency. A non-linear compensation software(213) performing a non-linear compensating process for the extracted radio frequency and generates a value of lookup table.