Design And Implementation Of Digital IF Wideband Receiver

With the development of ultra-high-speed,very large-scale integrated circuits and digital signal processing theory,software radio is becoming more and more important in the field of wireless communications.Receivers,as an important part of radio systems,are the inevitable trend of using software radio technology.However,the structure of an ideal software radio receiver requires extremely high pre-filter and A/D devices and is difficult to implement.Therefore,digital IF bandwidth architecture is an important way to achieve software radio.According to the thought of software radio,this paper presents a design scheme of digital IF wideband receiver.IF signal after a simple analog signal processing,the AD samples directly.the data collected after digital down conversion and digital demodulation uploaded to the host computer,digital intermediate frequency broadband receiver function.System uses a standard modular design,including high-speed sampling board,the system motherboard,the system floor of the three modules.High-speed sampling board designed based on the FPGA IF analog signal conditioning module,high-speed AD sampling module,PLL module,to achieve the ADC signal conversion,digital orthogonal down conversion and filtering extraction,and get low-rate baseband signal data.System motherboard design based on dual-core digital signal processor,the smallest system circuit and memory expansion circuit,core₁ completed baseband demodulation and sampling of baseband signal data decision function;core₀ running uC/OSIII to achieve System control,data storage and interaction with host computer.System floor through high-speed board-to-board connector to achieve data interaction of high-speed sampling board and system motherboard,and designed analog signal interface,network interface and high-capacity storage module according to the system needs,enriched the system functionality.The paper mainly introduced the principle and key technology of IF receiver,described the hardware and software design details of each module in detail,verified the function of the module and debugged the system as a whole,fulfilled the function requirement of digital IF wideband receiver.