LAB6:-Design of Chebyshev Filter

The aim of this experiment was to design a Chebyshev filter using Scilab software.Passband attenuation and frequency (Ap,Fp)  and Stopband attenuation and frequency (As,Fs) were given as input parameters to the filter design.The sampling frequency was set greater than 5 times max(Fs,Fp) .The magnitude response of the filter was plotted with frequency in Hz and Magnitude in dB.Ripples were observed in the pass band and the number of extremes in the ripples corresponded to the order of the filter.

Lab5:-Design of Butterworth Filter

The aim of this experiment was to design a Butterworth filter using Scilab software.As,Ap,Fs,Fp and sampling frequency were given as input parameters to the filter design and BLT method was used for filter design.The sampling frequency given as input was kept higher than 5 times the max(Fs,Fp). Magnitude response of the filter was plotted wherein frequency was kept in Hz and Magnitude in dB.It was observed that Magnitude response​ was monotonic (without ripple).

LAB4:-Filtering of data sequence

The aim of this experiment was to perform OAM(Overlap Add Method) and OSM(Overlap Save Method) in FIR-filter(Finite Impulse Response) to filter a sequential data input. Independent functions to perform OAM  and OSM separately were executed in C language which took length of the signal(in my case:13)as one of its arguments. It was observed that both techniques of filtering yielded the same output. Also we essentially observed that the function decomposed the input signal into blocks and computed them separately. This meant that both OAM and OSM are block processing techniques.

LAB3:-Fast Fourier Transform

The aim of this experiment was to perform Fast Fourier transform of a DT signal. A function in C was executed to perform Radix-2 Cooley and Tuckey's DITFFT algorithm which took the length of the signal as one of its arguments(length taken must be in exponential powers of 2).A counter was also implemented to calculate total number of real and complex multiplications and additions. The results obtained were verified mathematically using formulae for the same. Bit reversal was observed and the fact that FFT is a computationally faster algorithm than DFT was understood.  

LAB2:-Discrete Fourier Transform

The aim of this experiment was to perform Discrete Fourier Transform(DFT) of a DT signal. We executed a function in C to perform DFT of an N point signal by providing length of the input signal as one of its arguments. Multiplications and additions of complex terms were done separately by considering only their coefficients. The results obtained were plotted in the form of a magnitude spectrum(Magnitude vs frequency).It was observed that DFT results are periodic,inverse-DFT converges and DFT of an expanded signal results on compression of magnitude spectrum.     

LAB1:-Convolution and Correlation

The aim of the experiment was to perform linear convolution, circular convolution and linear convolution using circular convolution. We executed a C code for LC,CC and LC by CC on Terminal in Linux OS by using simple commands such as ('gcc','./a.out' etc.).The results obtained by running this code were verified by mathematical formulation. Key observations that were made were that Circular Convolution gives aliased output and Autocorrelation of input signal did not change even when it was delayed.