zulkaif.m

cognitive radio simulation

while(1)
    
    clc
    close all
    clear all
    
    t = 0:0.00001:0.001;
    Fc1 = 1000;
    Fc2 = 2000;
    Fc3 = 3000;
    Fc4 = 4000;
    Fc5 = 5000;
    Fs = 12000;
    y1 = 0; y2 = 0; y3 = 0; y4 = 0; y5 = 0; Y = 0; y = 0;
    x1 = cos(2*pi*1000*t);
    x2 = cos(2*pi*2000*t);
    x3 = cos(2*pi*3000*t);
    x4 = cos(2*pi*4000*t);
    x5 = cos(2*pi*5000*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(x2,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;
    
    if( y == 0)
        disp('All bands are available');
        break;
    else
        Pxx = periodogram(y);
        Hpsd = dspdata.psd(Pxx,'Fs',Fs);
        plot(Hpsd);
        
        chek1 = Pxx(25).*10000;
        chek2 = Pxx(49).*10000;
        chek3 = Pxx(62).*10000;
        chek4 = Pxx(89).*10000;
        chek5 = Pxx(105).*10000;
        
        if(chek1 < 8000)
            disp('User 1 is not present.');
        end

        if(chek2 < 8000)
            disp('User 2 is not present.');
        end
    
        if(chek3 < 8000)
            disp('User 3 is not present.');
        end
    
        if(chek4 < 8000)
            disp('User 4 is not present.');
        end

        if(chek5 < 8000)
            disp('User 5 is not present.');
        end
    
    end
    
    % Adding noise effect into the signal

    noise_in = input('Do you want to add noise effect? [Y/N]:   ','s');
    
    if(noise_in == 'Y' | noise_in == 'y')
        figure
        Y = awgn(y,0.01);
        Pxx1 = periodogram(Y);
        Hpsd = dspdata.psd(Pxx1,'Fs',Fs);
        plot(Hpsd);
    
        chek1 = Pxx1(25).*10000;
        chek2 = Pxx1(49).*10000;
        chek3 = Pxx1(62).*10000;
        chek4 = Pxx1(89).*10000;
        chek5 = Pxx1(105).*10000;

        if(chek1 < 8000)
            disp('User 1 is not present.');
        end

        if(chek2 < 8000)
            disp('User 2 is not present.');
        end

        if(chek3 < 8000)
            disp('User 3 is not present.');
        end

        if(chek4 < 8000)
            disp('User 4 is not present.');
        end

        if(chek5 < 8000)
            disp('User 5 is not present.');
        end

    else
        disp('Rerun the program again....');
        break;
    end
    
    %Adding Attenuation to the bands

    temp = input('Do you want to attenuate the signals? [Y/N]:    ','s');

    if(temp == 'Y' | temp == 'y')
        aF = input('Enter the percentage to attenuate the signal:   ');
        figure
        tem = aF/100;
        tm = 1-tem;
        Yf = y.*tm;
        Pxx2 = periodogram(Yf);
        Hpsd = dspdata.psd(Pxx2,'Fs',Fs);
        plot(Yf);
    
        chek1 = Pxx2(25).*10000;
        chek2 = Pxx2(49).*10000;
        chek3 = Pxx2(62).*10000;
        chek4 = Pxx2(89).*10000;
        chek5 = Pxx2(105).*10000;

        if(chek1 < 8000)
            disp('User 1 is not present.');
        end

        if(chek2 < 8000)
            disp('User 2 is not present.');
        end

        if(chek3 < 8000)
            disp('User 3 is not present.');
        end

        if(chek4 < 8000)
            disp('User 4 is not present.');
        end

        if(chek5 < 8000)
            disp('User 5 is not present.');
        end

    else
        disp('Rerun the program again....');
    end
    
    %if rerun the program
    
    temp = input('Do you want to re-run the program? [Y/N]:    ','s');
    
     if(temp == 'Y' | temp == 'y')
         disp('\n\nEnter the users again.\n\n');
     else
         break;
     end
end