Question

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%*******Parameter Settings********

%*********************************

Fs=8192; %Sampling frequency (MATLAB's default)

Ts=1/Fs; %Sampling time or sampling period

Vx=1; %Chirp signal time duration in seconds

A=1; %Amplitude of chirp signal

a=2*pi*3000; %Angular chirp rate (natural chirp rate is 3000)

b=1000; %Initial natural frequency in Hertz

%

Nx=Vx*Fs; %Number of samples of the generated chirp signal

Nxseg=round(Nx/16); %Length of a segment(1/16) of the chirp signal

txaxis=0:Ts:Nx*Ts-Ts; %Time-sampled axis (vector of time values)

Psx=1; %Pointer (>0) to the beginning of the segment sample

txseg=(Psx-1)*Ts:Ts:(Psx+Nxseg-2)*Ts; %Time-sampled axis for signal segment

fxinc=Fs/Nx; %Spectral resolution of x(t)

fxaxis=-(Fs/2):fxinc:(Fs/2)-fxinc; %Frequency axis

fsxinc=Fs/Nxseg; %Segment spectral resolution

fsxaxis=-(Fs/2):fsxinc:(Fs/2)-fsxinc; %Seg. freq. axis

%

%********Signals Generation*******

%*********************************

x=A*cos((0.5*a)*(txaxis.*txaxis)+2*pi*b*txaxis);

xseg=x(Psx:Psx+Nxseg-1); %Segment (1/16) of chirp signal

%

%*******Filtering Operations*******

%*********************************

Nh=251; %Bandpass filter order

Nhm1=Nh-1; %Filter parameter for fir1

Wn=[2*2000/Fs 2*(3500/Fs)]; %Nomalized cutoff frequency vector

hB=fir1(Nhm1,Wn); %Impulse response funtion

y=conv(x,hB); %Filtering the chirp signal

%

Ny=length(y); %Order or length of filtered signal

Nyseg=round(Ny/16); %Length of filtered signal segment(1/16)

Psy=1; %Pointer (>0) to the first filtered signal segment sample

yseg=y(Psy:Psy+Nyseg-1); %Segment (1/16) of filtered signal

tyaxis=0:Ts:Ny*Ts-Ts; %Time axis of filtered signal

tyseg=(Psy-1)*Ts:Ts:(Psy+Nyseg-2)*Ts;%Time-sampled axis for segment

fyinc=Fs/Ny; %Spectral resolution of y(t)

fyaxis=-(Fs/2):fyinc:(Fs/2)-fyinc; %Frequency axis

fsyinc=Fs/Nyseg; %Segment spectral resolution

fsyaxis=-(Fs/2):fsyinc:(Fs/2)-fsyinc; %Seg. freq. axis

%

%********Spectra Generation*******

%*********************************

X=fft(x); %Spectrum of x

sX=fftshift(X); %Change to the principal region

asX=abs(sX); %Magnitude of spectrum of x(t)

Xseg=fft(xseg); %Spectrum of xseg

sXseg=fftshift(Xseg); %Change to the principal region

asXseg=abs(sXseg); %Magnitude of spectrum of xseg(t)

%

Y=fft(y); %Spectrum of y

sY=fftshift(Y); %Change to the principal region

asY=abs(sY); %Magnitude of spectrum of y(t)

Yseg=fft(yseg); %Spectrum of yseg

sYseg=fftshift(Yseg); %Change to the principal region

asYseg=abs(sYseg); %Magnitude of spectrum of yseg(t)

%**********Signals Plots**********

%*********************************

plot(txaxis,x) %Chirp time-sampled input signal

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Chirp Input Signal x(t)')

grid

%

figure

plot(txseg,xseg) %Chirp time-sampled signal segment

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Chirp Input Signal Segment xseg(t)')

grid

%

figure

plot(tyaxis,y) %Chirp time-sampled filtered output signal

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Filtered Chirp Output Signal y(t)')

grid

%

figure

plot(tyseg,yseg) %Chirp time-sampled signal segment

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Filtered Chirp Output Signal Segment yseg(t)')

grid

%

figure

plot(fxaxis,asX)

xlabel('Frequency in Hertz')

ylabel('Magnitude')

title('Spectrum of Time-Sampled Chirp Input Signal x(t)')

grid

%

figure

plot(fsxaxis,asXseg)

xlabel('Frequency in Hertz')

ylabel('Magnitude in dB')

title('Spectrum of Time-Sampled Chirp Input Signal Segment xseg(t)')

grid

%

figure

plot(fyaxis,asY)

xlabel('Frequency in Hertz')

ylabel('Magnitude')

title('Spectrum of Time-Sampled Filtered Chirp Output Signal y(t)')

grid

%

figure

plot(fsyaxis,asYseg)

xlabel('Frequency in Hertz')

ylabel('Magnitude in dB')

title('Spectrum of Filtered Chirp Output Signal Segment yseg(t)')

grid

%

%**********Signals Sounds*********

%*********************************

disp('Sound of Generated Input Chirp Signal')

sound(x,Fs)

pause(05)

disp('Sound of Filtered Output Chirp Signal')

sound(y,Fs)

%

1. From the code above change the filter from a band-pass filter to a band-stop. You should also change the name of the impulse response function of the filter from hB to hS.

I JUST NEED THE MATLAB CODE that shows the change of filter.

Answer 1

ANSWER:

• For bandstop filter, we use fir1 function with ftype="stop".
• I have provided the properly commented code in both text and image format so you can easily copy the code as well as check for correct indentation.
• Have a nice and healthy day!!

CODE TEXT

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close all

%

%*******Parameter Settings********

%*********************************

Fs=8192; %Sampling frequency (MATLAB's default)

Ts=1/Fs; %Sampling time or sampling period

Vx=1; %Chirp signal time duration in second

A=1; %Amplitude of chirp signal

a=2*pi*3000; %Angular chirp rate (natural chirp rate is 3000)

b=1000; %Initial natural frequency in Hertz

%

Nx=Vx*Fs; %Number of samples of the generated chirp signal

Nxseg=round(Nx/16); %Length of a segment(1/16) of the chirp signal

txaxis=0:Ts:Nx*Ts-Ts; %Time-sampled axis (vector of time values)

Psx=1; %Pointer (>0) to the beginning of the segment sample

txseg=(Psx-1)*Ts:Ts:(Psx+Nxseg-2)*Ts; %Time-sampled axis for signal segment

fxinc=Fs/Nx; %Spectral resolution of x(t)

fxaxis=-(Fs/2):fxinc:(Fs/2)-fxinc; %Frequency axis

fsxinc=Fs/Nxseg; %Segment spectral resolution

fsxaxis=-(Fs/2):fsxinc:(Fs/2)-fsxinc; %Seg. freq. axis

%

%********Signals Generation*******

%*********************************

x=A*cos((0.5*a)*(txaxis.*txaxis)+2*pi*b*txaxis);

xseg=x(Psx:Psx+Nxseg-1); %Segment (1/16) of chirp signal

%

%*******Filtering Operations*******

%*********************************

Nh=251; %Bandpass filter order

Nhm1=Nh-1; %Filter parameter for fir1

Wn=[2*2000/Fs 2*(3500/Fs)]; %Nomalized cutoff frequency vector

% using ftype -> 'stop' in fir1 function to generate Band-Stop Filter

hS=fir1(Nhm1,Wn,'stop'); %Impulse response funtion

y=conv(x,hS); %Filtering the chirp signal

%

Ny=length(y); %Order or length of filtered signal

Nyseg=round(Ny/16); %Length of filtered signal segment(1/16)

Psy=1; %Pointer (>0) to the first filtered signal segment sample

yseg=y(Psy:Psy+Nyseg-1); %Segment (1/16) of filtered signal

tyaxis=0:Ts:Ny*Ts-Ts; %Time axis of filtered signal

tyseg=(Psy-1)*Ts:Ts:(Psy+Nyseg-2)*Ts;%Time-sampled axis for segment

fyinc=Fs/Ny; %Spectral resolution of y(t)

fyaxis=-(Fs/2):fyinc:(Fs/2)-fyinc; %Frequency axis

fsyinc=Fs/Nyseg; %Segment spectral resolution

fsyaxis=-(Fs/2):fsyinc:(Fs/2)-fsyinc; %Seg. freq. axis

%

%********Spectra Generation*******

%*********************************

X=fft(x); %Spectrum of x

sX=fftshift(X); %Change to the principal region

asX=abs(sX); %Magnitude of spectrum of x(t)

Xseg=fft(xseg); %Spectrum of xseg

sXseg=fftshift(Xseg); %Change to the principal region

asXseg=abs(sXseg); %Magnitude of spectrum of xseg(t)

%

Y=fft(y); %Spectrum of y

sY=fftshift(Y); %Change to the principal region

asY=abs(sY); %Magnitude of spectrum of y(t)

Yseg=fft(yseg); %Spectrum of yseg

sYseg=fftshift(Yseg); %Change to the principal region

asYseg=abs(sYseg); %Magnitude of spectrum of yseg(t)

%**********Signals Plots**********

%*********************************

plot(txaxis,x) %Chirp time-sampled input signal

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Chirp Input Signal x(t)')

grid

%

figure

plot(txseg,xseg) %Chirp time-sampled signal segment

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Chirp Input Signal Segment xseg(t)')

grid

%

figure

plot(tyaxis,y) %Chirp time-sampled filtered output signal

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Filtered Chirp Output Signal y(t)')

grid

%

figure

plot(tyseg,yseg) %Chirp time-sampled signal segment

xlabel('Time in Seconds')

ylabel('Amplitude')

title('Time-Sampled Filtered Chirp Output Signal Segment yseg(t)')

grid

%

figure

plot(fxaxis,asX)

xlabel('Frequency in Hertz')

ylabel('Magnitude')

title('Spectrum of Time-Sampled Chirp Input Signal x(t)')

grid

%

figure

plot(fsxaxis,asXseg)

xlabel('Frequency in Hertz')

ylabel('Magnitude in dB')

title('Spectrum of Time-Sampled Chirp Input Signal Segment xseg(t)')

grid

%

figure

plot(fyaxis,asY)

xlabel('Frequency in Hertz')

ylabel('Magnitude')

title('Spectrum of Time-Sampled Filtered Chirp Output Signal y(t)')

grid

%

figure

plot(fsyaxis,asYseg)

xlabel('Frequency in Hertz')

ylabel('Magnitude in dB')

title('Spectrum of Filtered Chirp Output Signal Segment yseg(t)')

grid

%

%**********Signals Sounds*********

%*********************************

disp('Sound of Generated Input Chirp Signal')

sound(x,Fs)

pause(05)

disp('Sound of Filtered Output Chirp Signal')

sound(y,Fs)

%

CODE IMAGE (OF CHANGED PORTION)