Eas Detection System Design Based On Dsp Technology

As a new type of electronic equipment in defending theft, electronic article surveillances are extensively applying in market spots. Because of the merits of simple principle, cheap cost etc., radio frequency style EAS systems are welcomed by most people. Through the several decades' development of digital signal process technology, it has been applied many fields successfully. Achieving the system using the digital signal processor has become a trend in designing such kind of device.The thesis brings forward a kind of design method of software and hardware in EAS based on the digital signal process technology. It improves the performance targets in some aspects such as responding speed, the ratio of mistaken alarm and the ratio of missed alarm. The article include such contents as below:1. The impedance matching, amplifying in band-pass, magnify and frequency demodulation, pulse shaping methods have been used to transform the signals;2. The digital signal processor with flash memory as the microprocessor has been selected, which elevate the responding speed of the system, simplifies the structure of system circuit; reduce the volume of the detector;3. Through the analysis and study plenty of data acquired by lots of experiments, the method to identify the signal of tags or labels, computing self-correlation fuction of continuous several terms under the self-corrrelation theory; is described.4. The feature parameters of the signal of tags or labels are obtained by the statistical method. The research shows that the feature parameters have better effect in resisting on the gusty interfere, improving the sensibility of the system and decreaseing the ratio of mistaken alarm;5. The remote monitoring and maintaining system using the public telephone networks is designed; the software of monitor center is designed and the hardware and software of EAS controller is devised.