%Question 1 - BPSK
x = 0:9;
message='SnirTomer';
S0=ones(1,10);
S1=-S0;

subplot(2,2,1);
stem(x, S0);
binary_message=dec2bin(message);
binary_message=[binary_message(1,:) binary_message(2,:) binary_message(3,:) binary_message(4,:) binary_message(5,:) binary_message(6,:) binary_message(7,:) binary_message(8,:) binary_message(9,:)];
N = length(S0);
before_noise = zeros(1,10);
for i=1:N

   if binary_message(i)-48 == 0
       before_noise(i) = S0(i);
   else
       before_noise(i) = S1(i);
   end
end

subplot(2,2,2);
stem(x, before_noise);

sd=15484; %15484 just for example
s=rng(sd);

for i=1:N
    temp = mod(randn(1,1),1);
    rf_signal(i) = before_noise(i) + temp;

end

subplot(2,2,3);
stem(x, rf_signal);


positive = zeros(1, 10);
negative = zeros(1, 10);

for i=1:N

    temp = rf_signal(i);
    if temp > 0
        positive(i) = temp;
    else
        negative(i) = temp;
    end
end


subplot(2,2,4);
stem(x, positive, 'green')
hold on
stem(x, negative, 'red')