STUDY ON NOISE CHARACTERISTICS OF LOW VOLTAGE POWER NETWORKS IN FREQUENCY REGION FROM 500kHz TO 10MHz AND ESTIMATION OF CHANNEL CAPACITY

It is interested in the solution of “the last mile” by use of low voltage power network and it is well known that for any communication system the study on the noise characteristics of the channels is necessary and very important. The results of noise characteristics measured in three typical low voltage power networks within the bandwidth from 500kHz to 10 MHz are given. The measured results include the background noise of power transmission lines, the noise from power equipments and the noise measured during 24 hours continuously. The characteristics of background noise and pulse noise which affects the communication system most is emphatically studied and such a conclusion is obtained that the noise level within the bandwidth from 500kHz to 10Mhz is much lower than that within the bandwidth from 10kHz to 450kHz. Finally, a rough estimation of channel capacity is presented.