Digital Signal Processing In Received Signal Of 900MHz Long-range Reader

The paper carried a lot of practice and gives a systematic treatment method of digital processing in dealing with received signal of 900MHz long-rang reader. First of all, by a description of 900MHzUHF reader system block diagram, this article Introduced the principle of work of the system and Illustrates the complexity and the core of the system where the digital signal processing will play an essential role. And then, by use SIMULINK Simulation tool makes simulation and comparison of several commonly used methods of engineering.choose a method of zero clear of combination of IQ which has the advantage. Article focuses on various key aspects of digital signal processing and carried out a detailed analysis. Contains the following, use ping-pong cache save ADC sampling data, Fixed-point arithmetic, Automatic Gain Control, Fast carrier recovery, DPLL, Compact method investigation tan table, Fast Implementation of NCO, Pipeline optimization under stringent timing and gives a lot of debugging process diagrams, waveforms.The paper also describes specific procedures for DSP algorithm implementation process by showing the flow chart and state diagram and gives the core procedures for reference. Test shows that reading distance becomes longer, the coherence of reader further enhanced, reader sensitivity Increased and able to resist the impact of certain automotive film. The algorithm can extract more info from the card signal, the card moving direction, speed and other information.