Design And Implementation Of Wideband Digital Channelized Receiver

As the important part of electronic warfare, the receiving and processing of the radar signals has been a hot point for research. With the appearance of LPI radar and frequency agility radar, signal environment of radar countermeasure appears the new characteristic which include a great number of radiation sources, large distribution density, serious signal overlapping and variable signal parameters, etc. This requires that the modern electronic warfare receiver must have the following features, wideband signals treatment, high sensitivity, large dynamic range, multi-signal parallel processing and much information real-time processing capacity. The digital channelized receiver can not only meet the above requirements better, but also achieve the full probability of intercept to the signals in the monitored band.The digital channelized receiver was studied deeply in the paper and recognition of intra-pulse modulation types was given on the basis of the above theory. A mathematical model of receiver used in the modern electromagnetic environment was derivated and validated by simulation, then the implementation method was given based on FPGA.This paper includes the following contents:Firstly, the sampling theory in the channelized receiver was introduced in detail, then the derivation of high-speed and efficient structure of the uniform digital channelized receiver based on polyphase filter and FFT was given in the paper. Due to frequency measurement of channelized subsequent processing, several methods of frequency measurement were discussed and the simulation error was given.Secondly, the paper analyzes the intra-pulse characteristics of modulated signal in detail. The simulation results of these methods was given based on analyzing signal recognition of intra-pulse modulation types.Furthermore, the paper introduces hardware design of the digital channelized receiver based on polyphase filter and gives the framework of system, FPGA's implements the every function module of system. What's more, the paper has analyzed and compared recognition of intra-pulse modulation types based on implementation of DSP and FPGA after the channelized processing. Finally, the article tests the system functions and the test data was given at the hardware platform built.