Research On Power Line Communication System Based On OFDM

Power Line Communication(PLC) takes power line as transmission media to complete a data transmission and information exchange.With the development of the technologies of modulation, transmission and signal processing, power line communication has been further developed. And the era of single-carrier modulation has terminated because of the emergence of multi-carrier modulation, and the transmission rate is improved greatly.This article through the analysis of technical characteristics of power lines communication technology and orthogonal frequency division multiplexing (OFDM) technology, summarizes their combining application reasons, which can be used as the basis for research. On this basis, the article summaries the characteristics of power line channel and its influences on transmission signal, sets up a voltage power line channel model for use. This paper studies the basic principle of the OFDM technology, and confirms the implementation of power line communication based on OFDM technology. Through the comparison and analysis, key technical solutions and realization methods are designed and finished in OFDM technology application process. The paper expounds the superiority of FFT algorithm in OFDM technology that is used in this system can be calling processor library function directly.On the basis of the related theoretical knowledge and the determine of OFDM key technologies'scheme, the core of hardware system design is STM32F103ZET6, the advantage of the chip is that low price. The cost is reduced, and at the same time the requirements of technical parameters are satisfied. The designs of A/D data sampling circuit, the power conversion circuit, memory interface circuit, JTAG interface circuit and other circuits are completed in Protel99 software. The implementation scheme of sending data, receiving data and synchronous are designed, which is based on this hardware platform in Power line carrier-current communication. The compiling and debugging of C program are finished in the IAR development environment. On the basis of hardware platform and software program test, the paper constructs a complete set of PLC system that carries out data transmission, and uses the observation window that designs by LabVIEW in PC, with a serial port observing transmission of data before and after all the time, thus process of using OFDM technology to perform in data transmission in power line is came true.