Research Of Auto Meter Reading Based On Low Voltage Powerline Carrier Spread Spectrum Communication

The technology of low voltage powerline carrier spread spectrum communication and the auto meter reading system based on it are introduced in this paper. As communication medium, the low voltage powerline has great potential in application. The chief researches of this paper are showed as follows:1) Noise characteristics, attenuation characteristics and impedance characteristics on the low voltage powerline are analyzed in this article. With the good ability of interference rejection of spread spectrum communication, auto meter reading system based on the technology may raise the precision and reliability of auto meter reading system while bad channel characteristics are the major obstacle of low voltage powerline carrier communication. In this paper ,a kind of approximate model which can reflect the basic feature of low voltage powerline channel is given.2) Error control coding is an effective method which can improve communication system. After the comparison among the various forms of error control and bit error rate of spread spectrum communication, cascade coding which can reduce the bit error rate of low voltage powerline carrier communication is selected. Through the simulation of Monte Carlo model, the performance of the low voltage powerline carrier spread spectrum communication system is displayed in this paper.3) When it comes to the big noise on the low voltage powerline, least mean square (LMS) adaptive filtering algorithm is a method which can improve the performance of spread spectrum communication system. On the basis of the improved LMS algorithms, a new adaptive variable step size LMS algorithm is proposed, and the performances of these algorithms are compared by simulations here.4) The structure and principle of the auto meter reading system designed based on our single-phase multi-rate watt-hour meter are introduced in this paper.