A new adjustable window function to design FIR filter and its application in noise reduction from contaminated ECG signal

A new adjustable window function, based on the combination of Blackman Window and Lanczos Window, has been proposed in this paper. The proposed window function is adjustable because its spectral characteristics and shape can be adjusted according to the desire of the designer by varying the controlling parameter of the function. The spectral characteristics of the proposed window have been analyzed and its performance has been compared with Gaussian, Lanczos and Kaiser Windows. From MATLAB simulation results, it is observed that the proposed window provides better ripple ratio than Gaussian and Lanczos Windows and better side-lobe roll-off ratio than Kaiser and Gaussian Windows. In addition, the proposed window function has been applied to design Finite Impulse Response (FIR) filter to justify the performance of it. The outcomes of the simulation have assured that the filter designed by the proposed window provides some better spectral characteristics and better gain than the other preceding windows. A contaminated ECG signal has also been filtered by using an FIR low pass filter designed by the proposed window.