Abstract: Digital filters are widely used in many Digital Signal Processing applications. Therefore, Digital Filtering is one of the basic needs of Digital Signal Processing. This paper introduces the definition and basic principles of FIR digital filters, and the design based on MATLAB. After the description of the process of design., the MATLAB program is Used to implement FIR filter using modified coefficient of Hamming window function and also calculate the equivalent noise bandwidth. Digital filters are pervasive in the present era of communication systems. As a result good digital filter performance is important and hence to design a digital finite impulse response (FIR) filter satisfying all the required condition is a demanding one. This report deals with the design of FIR digital filter using hamming window technique. This window is optimized to minimize the maximum (nearest) side lobe, giving it a height of about one-fifth that of the Hamming window. Hence this type of filter plays very important role in spectral analysis of different types of signal. In spectral analysis applications, a small main lobe width of the window function in frequency domain is required for increasing the ability to distinguish two closely spaced frequency components.

Keywords: FIR Filter, DSP, FFT, Rectangular Window, Taylor Window, Hamming Window, MATLAB.