Explaining BPSK Demodulation ?

Hi everyone,

I've a simple question (or it should be one).

I have a sequence, let's say it is u = [1 1 0]. I've modulate it using BPSK as u_BPSK = [-1 -1 1]. I've sent it through AWGN channel using the command I found on the internet.

y = u_BPSK + sqrt(N0/2)*(randn(size(u_BPSK))+i*randn(size(u_BPSK)));

where N0 is the noise power spectral density:

N0 = 1/(10^(SNRdB/10));

I just want to understand how this type of demodulation.

Thanks in advance.