Abstract: The input signal has a great influence on the performance of the system in digital control system. Processing of input signals is important to get useful signal in has processing of digital signal finite impulse response (fir) filter plays on important role. The aim of this paper is digital FIR filter designed by different window techniques perform better for reducing noise various window method such as Blackman window, Kaiser window, tucky window. We found that filter designing by window method is easy and fast.

Keywords: DSP, Digital Filter, Low Pass Filter, and Blackman Harris Window, Kaiser window and tukey window.