Implementation Of Power Line Multi-carrier Communication System Based On FPGA

Power line communication based on power line network is the physical medium of information interaction,which is the way to transmit data.Abundant power line resources offer a good foundation for promoting power line communication technology,according to construction without additional wiring,hardware costs are reduced.Although power line communication has bright prospects in the application,the electricity network is built for transferring electric power,rather than transmitting data.It is concluded that power line channel isn't the ideal transmission channel.Therefore,by adopting outstanding modulation technology,communication system can reduce adverse effects caused by power line channel and improve the reliability of signal transmission.In this thesis,the knowledge of the power line channel in relevant literatures were analyzed and researched.With the premise of comparing the existing power line carrier communication technology,the proposal of multi-carrier FSK communication based on traditional single-carrier FSK is made to deal with complicated channel noise and frequency selective fading etc.Multi-carrier communication system,which is making use of different frequency carriers to carry the same signals,sends data in frequency diversity mode,and system uses SNR estimation method based on M2M4 and power spectrum estimation method,receiving signals are merged in maximal ratio combining mode,the original signals are demodulated by using discrete short-time Fourier transform(DSTFT).According to the complex environment in power line channel,during the design process,core technologies which reduce the influence of frequency selective fading are analyzed and adopted,such as diversity and maximal ratio combining reception etc.And this thesis has elaborated the over-sampling technique,the power spectrum estimation based on DSTFT and SNR estimation algorithm based on M2M4.All these technologies applied in system improve the reliability of communication.In accordance with the design of multi-carrier communication system and the characteristics of the development platform named Nexys3 provided by Xilinx,functional modules contained key technologies are designed,the implementation of power line multi-carrier communication system based on FPGA is related to the system development suite named ISE.The system consists of UART communication module,modulation module,demodulation module and the external circuitry.Finally,the performance of the power line multi-carrier communication system with its core modules are tested,by analyzing the actual results,the fact that the system is capable of transmitting data accurately and efficiently has been verified,and the bit error rate meets actual requirements.