The Designs Of A Power Line SSC Data Communication System

The administer of big model and important electrical equipment in network is the new field of network technique . How to realize effectually the communication between electrical equipment and network is a focus of this field . Traditional power line carrier communication has some shortcomings on communication quality, which let it doesn't adapt to the dement of the power developing. Although many new communications means, such as microwave, optical fiber, etc, perform satisfactorily, the investment is tremendous and the construction period is long. If we can apply the spread spectrum technique on power line, improve the quality of the power line carrier communication, make the better use of the existing power line resource, then we can resolve the channel-lacking problem and bring direct and considerable social economic benefit. This scientific research project bases on this starting point, develops the spread spectrum digital transmission system which can accomplish the digital transmission on power line.The design select the direct sequence spread spectrum technology, which resolve the problem of the signal transmission in such adverse communication circumstances as power line; select the spectrum domain adaptive filtering technology, which has characteristics of high speed and powerful rejection for noise and interference.The paper firstly analyses the fundamental principles of the direct sequence spread spectrum technique, the arithmetic in the frequency-domain by using the technology of the spectrum correlation adaptive filter. Secondly, the hardware designand the software development are thoroughly discussed. The hardware design includes PL2101 power line node, realization of narrow-band interferences in direct sequence spread spectrum signal using frequency-domain algorithm. The software development comprises the compile of the microcontroller's assembly program and the compile of the communication program between the computer and the microcontroller. At last, the debugging and the performance analysis are conducted. The results show this digital transmission system performs superiority, pays cheaply. It can be used on the occasion of data transmission rate moderate , communication reliability demand high, such as power network automation distribution network automation and remote automatic metering system and so on.