Digital filtering occupies an extremely important position in the digital signal processing. Digital filtering is a basic algorithm in the application of the voice and image processing, pattern recognition, spectral analysis and etc. It is beneficial to use digital filter and not use analogue filter in many signal processing applications. FIR digital filter is easy to achieve different amplitude and phase frequency characteristic index, and overcomes the voltage drift, temperature drift and noise problems related to the analogue filter. And using the DSP chip to achieve digital filter has good stability, high accuracy and good flexibility characteristics. Therefore, this subject choice DSP to achieve digital filter.
This paper mainly studies the digital filter's basic theory and the implement methods. Then it studies how to use MATLAB software to design the digital filter that satisfies all the requirements, and gets the corresponding filter parameters, and provides the necessary data for the implement on DSP. This subject choices the platform of the TMS320VC5402 DSP /ARM Embedded comprehensive experimental system for the development. Finally it programs the FIR filter with window function using the filter coefficients simulated with Matlab in the CCS environment, and gets the filtering results, and the results are analyzed and summarized.
Experimental results show that the fitering effect using the Blackman window is better as to the test signal of the 0.01 Hz sine wave adding the 0.25Hz sine wave, and it can basically achieve the filtering requirements.
Key words：FIR digital filter; DSP; MATLAB; CCS; window function
