The Design And Implementation Of High-speed Transmission System Based On QAM

Modulation and demodulation techniques are core techniques of data transmission systems, as well as bottleneck restricting the high-speed data transmission system. The 16 QAM research of high-speed transmission has a very broad application prospects not only to improve the data transfer capability, but also for our country in the military field in the data transmission system and communications forwarding system. The high stability and reliability of high-speed transmission is particularly important in the real-time transmission of uncompressed HD images, onboard data backhaul and radio direction finding and monitoring and other fields. Therefore, as my paper topic, the research and development of high-speed transmission technology research 16 QAM, has far-reaching significance.The first part of paper is the theory of 16 QAM transmission depth comparative study. Reference for the research in the same field abroad, we put forward the overall program. Impact of major technical indicators and channel transmission characteristics of 16 QAM modulator of the whole system for simulation and verification, to carry out research for the next phase of 16 QAM project provides a good theoretical basis. This part further puts forward the improvement project of 16 QAM demodulation, and design model and simulation model is established.Secondly, a lot of research on the key technologies of the receiving system IF and baseband signal processing module is carried out, the main content of the processing is the digital downconversion, the present design is more efficient fractional times extracted gear filter architectures, efficient structure wherein is CIC filter and half-band filter design, the design of which variable rate reached 42 as many stalls, which can meet the needs of the users more flexibility.Finally, for high-speed transmission systems, this paper presents a scheme based on the high-speed transmission protocol PCIE through demand analysis, combined with the Xilinx FPGA implementation of high-speed bus, design a detailed hardware solutions and PCIE protocol configuration PIO, DMA, interrupt control functions logic design debugging and validation to achieve high-speed data transmission.According to the needs of the project, based on the completion of a high-speed digital QAM transmission system downconversion, 16 QAM modulation and demodulation based PCIE-based high-speed transmission protocol module based design and conduct of the inverter module and high-speed digital transmission module hardware implementations carried out under and test results of the individual functional units can normally reliably meet the preset targets and engineering application requirements, in a lot of practice and test performance and stability.