Dynamic Spectrum Access (DSA) in Wireless Cognitive Radio Networks (WCRN)

Cognitive Radio Matlab Source Code

clc close all t = 0:0.00001:0.001;
Fc1 = 1000;
Fc2 = 2000;
Fc3 = 3000;
Fc4 = 4000;
Fc5 = 5000;
Fs = 12000;

y1 = 1; y2 = 0; y3 = 0; y4 = 0; y5 = 0; Y = 0; y = 0;

x1 = cos(2*pi*1000*t);

in_p = input('\nDo you want to enter first primary user Y/N: ','s');

if(in_p == 'Y' | in_p == 'y')

y1 = ammod(x1,Fc1,Fs);

end

in_p = input('Do you want to enter second primary user Y/N: ','s');

if(in_p == 'Y' | in_p == 'y')

y2 = ammod(x1,Fc2,Fs);

end

in_p = input('Do you want to enter third primary user Y/N: ','s');

if(in_p == 'Y' | in_p == 'y')

y3 = ammod(x1,Fc3,Fs);

end

in_p = input('Do you want to enter fourth primary user Y/N: ','s');

if(in_p == 'Y' | in_p == 'y')

y4 = ammod(x1,Fc4,Fs);

end

in_p = input('Do you want to enter fifth primary user Y/N: ','s');

if(in_p == 'Y' | in_p == 'y')

y5 = ammod(x1,Fc5,Fs);

end

y = y1 + y2 + y3 + y4 + y5;

while(1)

Pxx = periodogram(y);

Hpsd = dspdata.psd(Pxx,'Fs',Fs);

plot(Hpsd);

in_p = input('\nDo you want to enter a secondary user Y/N: ','s');

if(in_p == 'Y' | in_p == 'y')

tp=0;

chek1 = Pxx(25)*10000;

chek2 = Pxx(46)*10000;

chek3 = Pxx(62)*10000;

chek4 = Pxx(89)*10000;

chek5 = Pxx(105)*10000;

if(chek1 < 8000)

disp('Assigned to User 1 as it was not present.');

y1 = ammod(x1,Fc1,Fs);

elseif (chek2 < 8000)

disp('Assigned to User 2 as it was not present.');

y2 = ammod(x1,Fc2,Fs);

elseif(chek3 < 8000)

disp('Assigned to User 3 as it was not present.');

y3 = ammod(x1,Fc3,Fs);

elseif(chek4 < 8000)

disp('Assigned to User 4 as it was not present.');

y4 = ammod(x1,Fc4,Fs);

elseif(chek5 < 8000)

disp('Assigned to User 5 as it was not present.');

y5 = ammod(x1,Fc5,Fs);

else

disp('all user slots in use. try again later,');

tp=1;

end

figure

y = y1 + y2 + y3 + y4 + y5 ;

Pxx = periodogram(y);

Hpsd =