Pulse Modulation Signal Parameter Measurement And Analysis

One of the most important features of Modern Military Technology is weapon systems more and more extensive use of radio-electronic technology and the radar is one of the most important application areas. Radar reconnaissance system receives the signals transmitted by the radar, measures the direction, frequency and other modulation parameters of the radar, determines the function, working status and level of threat of the radar according to the prior information and prior knowledge mastered already and provides the jammer and other related equipments with the results of various signals. In the radar environment there are a lot of pulse modulated Radio Frequency and microwave signals, the carrier wave frequency mearment of these signals is of great significance in the electronic warfare. For the conventional pulse modulated signals of the radar, this dissertation introduces the method of pulse carrier frequency measurement, uses direct IF sampling method to acquire IF signal and stores to DDR SDRAM, the main contents include:1.CPCI Bus Interface Standard: CPCI Bus is a high performance industrial bus acceptable for 3U and 6U board design based on the PCI Bus specification. CPCI not only allow many PC-based technologies and products such as CPU, hard disk and so on to continue to use but also becarse of the significant improvement of interface, making the server and industrial computers using CPCI technologies have high reliability and high density advantages;2.Carrier Frequency Measurement of modulated signals:Using the method of digital frequency measurement to implement the quickly measurement of the carrier frequency, designing amplification and shaping circuits, implementing equality precision frequency measurement algorithm based on phase-shift clock inside FPGA;3.IF signal acquisition:Using a high sampling rate, high precision and low power consumption ADC to complete the sample of the IF signal and storing the data to a high speed mass storage DDR SDRAM and using DMA technology to transfer the data on to PC; 4.Control logic of FPGA:Related to the equality precision frequency measurement control logic, DDR Controller, CPCI interface control logic and so on.