how to check the random bits that were found?

Good night people.

I made the code below to add a watermark to an RF signal.

I'm having trouble testing whether b_w is equal to Bit_wat1.

The real part is right (with the same b-inf = Bits_ale = s), but the Imag part (Bit_wat1 and b_w) that I can't get right.

Could someone give me a guess ????

clc

% BPSK - usa mudança de fase anti-podal para codificar um unico bit
M = 2;                 

% número de bits (símbolos)
N = 16;   

% Não sei o que é????
nS = 1;

% Bits de duração
Tb=1;

% frequência da portadora
fc = 1e6; 

% Tempo
t = 0:(Tb/(nS)):N*Tb-(Tb/(nS));

% comprimento - em função do tempo e dos numeros de bits
nt = round((N*t));


% Gera bits aleatórios para o sinal 
Bits_ale = rand(1,length(nt))>0.5; 

% Modulação BPSK - Transforma 0 -> -1; 1 -> 1
s = 2 * Bits_ale-1 ;                       

% Gera bits de marca d'água aleatórios
Bit_wat = rand(1,length(nt))>0.5; 
Bit_wat1 = 2 * Bit_wat - 1;

% Transmissor
Tx = s;

% Gera marca d'água a XX grau do ideal
wat = 28*(pi/180)*(Bit_wat1);



y=zeros(N,1);


for k=1:N 
    
        if (Bit_wat1 ==1)
         y = Tx .*exp(1i.*(2*pi*fc*t+wat)) ;  
    
        else
          y = Tx .*exp(1i.*(2*pi*fc*t-wat)) ; 
                      
        end
end



 b_inf=zeros(1,N);
 
 b_w=zeros(1,N);
 
 
  
for w= 1:N
   
       
       if real(y(w)) >= 0
        
            b_inf(w) = 1;
        
        
       else
        	b_inf(w) = 0;
        
        end
    
end




for x= 1:N
   
       
       if imag(y(x)) >= 0
        
            b_w(x) = 1;
        
       else
            b_w(x) = -1;
        
        end
    
end

re=real(y);
i=imag(y);

[Sindar]

This loop doesn't involve the loop variable k - you're doing the same thing N times:

for k=1:N
    if (Bit_wat1 ==1)
        y = Tx .*exp(1i.*(2*pi*fc*t+wat)) ;  
    else
        y = Tx .*exp(1i.*(2*pi*fc*t-wat)) ;
    end
end

Also, these loops

b_inf=zeros(1,N);
b_w=zeros(1,N);
for w= 1:N
    if real(y(w)) >= 0
        b_inf(w) = 1;
    else
       	b_inf(w) = 0;
    end
end
for x= 1:N
    if imag(y(x)) >= 0
        b_w(x) = 1;
    else
        b_w(x) = -1;
    end
end

can be replaced with:

b_inf = double( real(y) >= 0 );
b_w = -1 + 2*( imag(y) >= 0 );

[adriane duarte]

thanks for the help.

I'll do the code check.