def cal_snr_blind_qpsk(E):
"""
Calculates the SNR of a QPSK signal based on the variance of the constellation
assmuing no symbol errors"""
E4 = -E**4
Eref = E4**(1. / 4)
#P = np.mean(abs(Eref**2))
P = np.mean(cabssquared(Eref))
var = np.var(Eref)
SNR = 10 * np.log10(P / var)
return SNR
def test_cabssquared(self):
s = signals.SignalQAMGrayCoded(64, 2**12)
s2 = helpers.cabssquared(s)
assert type(s) is type(s2)
def test_cabssquared(self, nmodes):
s = signals.SignalQAMGrayCoded(64, 2**12, nmodes=nmodes)
s2 = helpers.cabssquared(s)
assert s.shape == s2.shape