The Originating Characteristics of Periodic Impulse Noises in the Data Communication System by Distribution Line Carrier Method

배전선반송 데이타통신에서의 주기적 임펄스노이즈의 발생특성

The existence of peroodic impulse noises in distribution line carrier (DLC) communication system is known to be the most serious obstacle for improving DLC communication quality in reliability and capacity. From the spectral points, impulse noises can be divided into baseband type and modulation type the noise width of whichs are much different each other. With each nose type, this study presents the basic characteristics in relation to what they originate from and how their spectrum properties are revealed. The baseband type impulse noise is normally caused from thyristor circuit running with low switching speed and the modulation type noise from the circuit of switching power supply. The base wave of modulation noise is shown to be the pulsuatic charging current to primary condenser in switching power circuit. The study result indicates also that placing the DLC carrier frequency away the band predominated by modulated noise especially from RCC type switching power circuit is very important in DLC design.