Spread Spectrum Analog Signal Source Design And Implementation Base On FPGA

Signal generator is an important part in a control system. It is significant to design a digital signal generator with high-precision, reliability and adjustable parameters, which can promote the development in some fields, such as aviation, spaceflight, national defense and industry automation. The paper mainly focuses on the design and realization of direct frequency and false random yard, and proposes the model design of the hardware based on the analysis and study of the questions, such as the theory of spread spectrum communication, the structure of signal source, design of the carrier wave is modulated and the filter.Field Programmable Gate Array (FPGA), because of its flexible designing and high speed, has been used more widely in digital ASIC. The paper introduces the development and the application of the technique of FPGA, including the basic VHDL language grammar, develop process and so on. The signal source with low phase noise, high resolution, high-accuracy and high stability is proposed, which adopts the direct digital synthesizer (DDS), based on the analysis of different frequency synthesizers. The choice of false distance measurement random yard is studied, the shifted array is decided to be the expanded frequency code array of the system and shifted array, which is fit for the system, is chosen, based on the analysis of the distance measurement random yard. And the paper analyzes each FPGA hardware circuit.Binary system phase-shift keying phase trial-and-error method is chosen and the hardware is realized as to the key technique of the modulate carrier wave. Finally output waves of the design are shown in the paper. The results of laboratory experiments show that the generator has the advantages of simple structure, light weight and small volume, which can satisfy the demands of debugging servo system, and has a promising application prospect.