Design And Implementation Of OFDM Data Transport System Based On ZYNQ

Orthogonal Frequency Division Multiplexing which is the primary modulation and multiple access technology,greatly increases the communication rate and been widely used by its efficient utilization in frequency band,excellent anti-multipath capability and flexible multiple access in the environment of increasingly crowded frequency band usage.The ZYNQ series development board introduced by Xilinx adopts a new architecture,which is suitable for implementing a complete communication protocol.The hardware acceleration of the physical layer communication algorithm is performed by FPGA,and the protocol layer data scheduling is implemented on the ARM core.The function that can be done by two development boards is integrated into one board,which greatly saves the space occupied by the hardware.In this paper,the research focuses on the implementation of OFDM system,the research and implementation of OFDM communication algorithm and the data interaction with the upper layer.In the study of OFDM technology and implementation,this paper first gives a theoretical introduction of OFDM and analysis in anti-multipath capability.Then researching and simulated the performance of multiple timing synchronization algorithms,carrier synchronization algorithms and channel estimation and equalization algorithms in the receiving end.Finally,this section selects the most suitable algorithms according to the communication environment of the application and hardware resource size of ZYNQ.When implementing the OFDM system,this paper first designs a reasonable OFDM frame structure by combining the application environment and parameter indicators.The pilot signal is added at the transmitting end to realize the modulation of OFDM,and the framing transmission of the OFDM symbol is completed in combination with the training sequence.At the receiving end,the OFDM timing synchronization,carrier frequency synchronization,channel estimation and equalization,residual phase tracking and QAM demodulation are respectively implemented.Finally,combined with the AD9361 highperformance RF chip,the baseband data is modulated into the RF band to make this OFDM system more complete in RF transmitter and receiver.When combined with the ZYNQ development board,the system performs software programming on the ARM side,which realizes the function of uploading demodulated data to the host computer through Gigabit Ethernet at high speed.It mainly realizes the high-speed data moving between FPGA and ARM core through DMA channel,and then transmits the data to the host computer stably and reliably in the ARM core with Gigabi t Ethernet in TCP/IP protocol.