Using biterr with negative numbers

I am tryig to calculate the bit error of a signal with negative values. bitterr will not accept negative values. Is there a trick?

s = -1 + 2*randi([0 1],100,1); % signal of -1 and 1's

n = wgn(100,1,-10); % white gaussian noise variance of -10 dBW

sn=s.*n % signal and noise - this math may be wrong...

[num, ratio]=biterr(s,sn)

Answer 1

[John D'Errico]

Did I not just answer how to solve essentially the same problem, but in the other direction? Read my answer to your last question. If you have a random sequence that is -1 or 1, can you convert it to the [0,1] sequence that biterr needs to see?

What if you added 1, then divide by 2?

That would map -1 into 0, and 1 back into 1.

[Joe Dombroski]

Since I am dealing with a AC signal and noise, I thought that I would need to stay in that polarity. I guess I could use a signal that alternates from 0 to 2 to maintain the signal amplitude and SNR. Then I have to deal with shifting the gausian noise to all positive.