Research And Design Of Digital Channelized Receiving System Based On Comb Filtering

As the development of modern radar technology, the battlefield electromagnetic environment isbecoming more and more complicated. Various kinds of radar, communication and other interferingsignals pile up in high density The development of high performance electronic reconnaissancereceiving system is becoming an important task. Digital channelized receiving system is an electronicwarfare （EW） receiving system with great development protential, which provides large dynamicrange, high sensitivity, wideband frequency coverage,etc.This thesis investigates two kinds of digital channelized methods, and mainly studies the FPGAdesign scheme of digital channelized receiver based on comb filtering.The techniques of two kinds of efficient digital channelized technology are studied. which aredigital channelized receiver based on polyphase filtering and comb filtering, respectively,from whichThe mathematical models of these two kinds of channelized receiver are derived.To the channelizedstructure based on comb filtering, its receiving system overall design scheme is given.The signal processing and encoding part after comb filtering channelized are studied anddesigned with the consideration of specific platform and performance index. The design method ofsignal detecting module after channelized is given, the common problems and their solutions whichaffect the system signal detecting accuracy are studied. The signal parameter estimation method andthe identification scheme for common radar signal modulation methods are studied.The whole digital channelized receiver based on comb filtering on the XC6VLX240T FPGA chipis realized. Each module’s FPGA implementation methods are introduced, The whole system istested,and its performance indicators are achieved. The advantages and disadvantages of combfiltering system relative to polyphase filtering system are analyzed.The design can deal with4signals arriving in the same time, identify typical modulationmode,including Normal Signal, Linear Frequency Modulation signal, Phase Shift Keying signal,estimate common signal parameters, including Instantaneous Frequency, Initial Phase, Time ofArrival, Pulse Width, Pulse Amplitude, etc. The system can detect signal when SNR is-7dB, itsdynamic range is40dB, bandwidth covers2GHz. The system is simple, fast and precise. It satisfiesthe instantaneity requirement of parameter estimation.