Lab DSP Essay Example | Topics and Well Written Essays - 1000 words

Lab DSP - Essay Example Table 1 indicates that expected values are the same with program’s values. Rectangular window function was utilized to design low-pass filters in MATLAB with window length M=2, 45, 65 and ω=0.2 as cut-off frequency. The graphs for impulse response, pole-zero, and magnitude function (linear as well as dB) were drawn. In the first experiment, three LPFs of varying lengths, length M = 25, 45, 65 as well as a 0.2π cut-off frequency were designed. Many observations were made during filter design process. The rectangular function’s main lobe width is 4π/M. The main lobe’s width narrows as M increases, affecting transition width and increasing its gradient. Increasing M reduces a large transition width, which is an unwanted effect. The area below the side lobes remain unchanged with signals retaining the ripples. High side lobe as well as stopband attenuation of -13 db and -21 dB respectively makes the rectangular function undesirable to use. Using a different window function with lower side lobes as well as stop band attenuations is the only way to overcome. Poles-zeros plot significantly affect response frequency when ascertaining the poles/zeros position in the unit circle, thus remain very crucial for the experiment. Unit circle zeros make response to move towards zero, which are components of stopband range. Zeros that are components of passband range produce ripples during passband frequency, thus impact the signal, which consequently affects filter accuracy. Zeros ranging 0-π are crucial because those that are outside do not have impact on the filter response. The poles at zero only have impact on the height of the passband. All window functions, including rectangular, hamming and Blackman, were used in MATLAB to design low-pass filters where length, M was 25 and cut-off frequency was ω=0.2. The graphs for impulse response,