Research And Implementation Of High Precision Broadband Real Time Spectrum Analysis Technology Based On The Decomposition Of The Channel

Wide band real-time spectrum analysis provides important technical guarantee for the normal operation of communication, radar, remote sensing and other systems. How to detect and analyze more fine spectrum under the condition of wide frequency band has been the focus of the research in the field of spectrum analysis all the time. Based on the structure of traditional hardware and software, the spectrum detection platform has been difficult to meet the needs of mankind. Through dividing the receiving frequency band, the digital channelized receiver provides a powerful technique support for obtaining the high accuracy frequency spectrum, of which the ingenious utilize of decimation factor make the efficient filtering structure for real, also reduced the consumption of resources effectively. Therefore, the research of channel decomposition of the spectrum analysis has important theoretical and practical significance for the development of spectrum analysis technology.The dissertation use channel decomposition technique to deal with data and get the spectrum information based on the digital intermediate frequency technology. In the process of implementation, The author analyzes kinds of ideas and techniques, including data sampling theory, digital down conversion processing, channel of the polyphase filtering, spectrum analysis and so on. To be specific:?when introducing the data acquisition circuit board, the dissertation introduces the advantages and disadvantages of low-pass sampling theorem, bandpass sampling theorem;?In digital down conversion processing part, the dissertation introduces the design simulation and FPGA hardware implementation of three modules, which are asynchronous signal processing, digital signal mixing and anti aliasing efficiently extract filter decimation filter group, and with emphasis on the anti aliasing cascade structure of stack, decimation filter module and determine the cascaded integrator comb filter(CIC filter group) and half band filter group(HB filter group) decimation ratio and various decimation ratio match to meet the requirements of the test under the different needs of users;?In channel of polyphase filtering module first on channel polyphase filtering algorithm of mathematical derivation and construct System Generator simulation realization structure, secondly on the dual channel compensation and polyphase filtering for FPGA hardware realization, data channel of decomposition, grouping according to DSP for deal with the Fourier transform to get the desired spectrum information, the DSP in dealing with large quantity of spectrum data at the same time to ensure the real-time requirements of the system and improve the spectrum efficiency analysis;?In the spectral analysis part, the dissertation verifies the intermediate frequency processing system and each sub module, and analyzes the spectrum information.The final results of the analysis are as follow, the module can realize the real-time spectrum analysis bandwidth for 40MHz~20KHz, when the real-time analysis of bandwidth is 20 KHz, the frequency resolution is 1.25 Hz, the actual processing results show that the equilibrium real channel decomposition technique based spectrum analysis system can be a very good analysis of the relationship between bandwidth and frequency resolution, which meets the requirements in a wide frequency band of fine spectral detection.