half of the progarm showing error

clc clear

% Generation of bit pattern s=round(rand(1,25)); signal=[]; carrier=[]; t=[0:2*pi/119:2*pi] for k=1:25 if s(1,k)==0 sig=-ones(1,120); else sig=ones(1,120); end c=cos(t); carrier=[carrier c]; signal=[signal sig]; end subplot(4,1,1); plot(signal); axis([-100 3100 -1.5 1.5]); title('\bf\it Original Bit Sequence');

bpsk_sig=signal.*carrier; subplot(4,1,2); plot(bpsk_sig) axis([-100 3100 -1.5 1.5]); title('\bf\it BPSK Modulated Signal');

t1=[0:2*pi/9:2*pi]; t2=[0:2*pi/19:2*pi]; t3=[0:2*pi/29:2*pi]; t4=[0:2*pi/39:2*pi]; t5=[0:2*pi/59:2*pi]; t6=[0:2*pi/119:2*pi]; c1=cos(t1); c1=[c1 cc1c1c1c1c1c1c1c1 c1]; c2=cos(t2); c2=[c2 c2c2c2c2 c2]; c3=cos(t3); c3=[c3 c3c3 c3]; c4=cos(t4); c4=[c4 c4 c4]; c5=cos(t5); c5=[c5 c5]; c6=cos(t6);

spread_signal=[]; for n=1:25 c=randint(1,1,[1 6]); switch(c) case(1) spread_signal=[spread_signal c1]; case(2) spread_signal=[spread_signal c2]; case(3) spread_signal=[spread_signal c3]; case(4) spread_signal=[spread_signal c4]; case(5) spread_signal=[spread_signal c5]; case(6) spread_signal=[spread_signal c6]; end end subplot(4,1,3) plot([1:3000],spread_signal); axis([-100 3100 -1.5 1.5]); title('\bf\it Spread Signal with 6 frequencies');

freq_hopped_sig=bpsk_sig.*spread_signal; axis([-100 3100 -1.5 1.5]); title('\bf\it Frequency Hopped Spread Spectrum Signal');

figure,subplot(2,1,1) plot([1:3000],freq_hopped_sig); axis([-100 3100 -1.5 1.5]); subplot(2,1,2); plot([1:3000],abs(fft(freq_hopped_sig)));

[shailaja]

thanku sir...only one output is not showing otherwise its worthy..

[Iman Ansari]

You didn't specify any graph for subplot(4,1,4)

Answer 1

[Iman Ansari]

Hi. you need to correct these lines:

c1=[c1 cc1c1c1c1c1c1c1c1 c1]; 
c2=cos(t2); 
c2=[c2 c2c2c2c2 c2];

I edited it:

clc 
clear
% Generation of bit pattern 
s=round(rand(1,25)); 
signal=[]; 
carrier=[]; 
t=[0:2*pi/119:2*pi] 
for k=1:25 
    if s(1,k)==0 
        sig=-ones(1,120); 
    else
        sig=ones(1,120); 
    end
    c=cos(t);
    carrier=[carrier c]; 
    signal=[signal sig]; 
end
subplot(4,1,1);
plot(signal); 
axis([-100 3100 -1.5 1.5]); 
title('\bf\it Original Bit Sequence');

bpsk_sig=signal.*carrier; 
subplot(4,1,2); 
plot(bpsk_sig) 
axis([-100 3100 -1.5 1.5]); 
title('\bf\it BPSK Modulated Signal');

t1=[0:2*pi/9:2*pi]; 
t2=[0:2*pi/19:2*pi]; 
t3=[0:2*pi/29:2*pi]; 
t4=[0:2*pi/39:2*pi]; 
t5=[0:2*pi/59:2*pi]; 
t6=[0:2*pi/119:2*pi]; 
c1=cos(t1); 
c1=[c1 c1 c1 c1 c1 c1 c1 c1 c1 c1 c1 c1]; 
c2=cos(t2); 
c2=[c2 c2 c2 c2 c2 c2]; 
c3=cos(t3); 
c3=[c3 c3 c3 c3]; 
c4=cos(t4); 
c4=[c4 c4 c4]; 
c5=cos(t5); 
c5=[c5 c5]; 
c6=cos(t6);

spread_signal=[]; 
for n=1:25 
    c=randint(1,1,[1 6]); 
    switch(c) 
        case(1) 
            spread_signal=[spread_signal c1]; 
        case(2) 
            spread_signal=[spread_signal c2]; 
        case(3) 
            spread_signal=[spread_signal c3]; 
        case(4) 
            spread_signal=[spread_signal c4]; 
        case(5) 
            spread_signal=[spread_signal c5]; 
        case(6) 
            spread_signal=[spread_signal c6]; 
    end
end
subplot(4,1,3) 
plot([1:3000],spread_signal); 
axis([-100 3100 -1.5 1.5]); 
title('\bf\it Spread Signal with 6 frequencies');

freq_hopped_sig=bpsk_sig.*spread_signal; 
axis([-100 3100 -1.5 1.5]); 
title('\bf\it Frequency Hopped Spread Spectrum Signal');

figure;
subplot(2,1,1) 
plot([1:3000],freq_hopped_sig); 
axis([-100 3100 -1.5 1.5]); 
subplot(2,1,2); 
plot([1:3000],abs(fft(freq_hopped_sig)));