Design And Verification Of 16QAM Modem For Power Line Communication Based On OFDM

Power line communication is a communication method for data transfer and information exchange in the transmission medium of power line. Although power line carrier communication is a technology that appeared in several decades ago, it has been widely used in many fields such as smart grid, smart home and intelligent transportation in recent years. Orthogonal Frequency Division Multiplexing(OFDM) is considered as the main stream technology in the communication environment with frequency selective fading characteristics.In this paper, the characteristics of the low voltage power line channel are introduced, according to the basic principle of OFDM technology, the key technology and engineering implementation methods of OFDM system are analyzed. Then, the physical layer of the IEEE 1901.2 narrow band power line communication is introduced. The overall frame and frame structure of the OFDM system are determined, the system bandwidth is 35.938kHz-90.625kHz, the sampling frequency is 400kHz, the sub-carrier number is 36, and the 16QAM modulation is adopted. Then the main module modeling on OFDM system is designed, including channel coding, modulation mapping, Fourier transform module, OFDM system dynamic simulation system is built. Finally, the FPGA chip for this topic is selected, the key module of OFDM system is designed by using Verilog HDL. The transmitter and receiver of OFDM system are simulated completely in ModelSim SE 10.1c, and then the transmitter and receiver module are synthesized and implemented by using ISE 14.5 platform. After this, the Verilog HDL program is downloaded into FPGA development board. Finally, the test platform of FPGA development board is set up, and the data and the original data transmitted by the transmitter are compared to verify the correctness of the FPGA implementation of the OFDM system.In this paper, the design and verification of IEEE 1901.2 standard physical layer of FPGA prototype system is completed. It is a solid foundation for the next step of the design of integrated circuits, and also it has important significance for the promotion and commercial application of OFDM technology in the low voltage power line communication technology.