Rho (ρ)

ρ is a measurement that evaluates modulation quality. It is calculated by finding the correlation between the recovered waveform and an ideal waveform that has been reconstructed from the demodulated bits. That is, the received demodulated waveform is compared to an ideal waveform obtained by remodulating the output bit stream of the digital demodulation VI. The ρ measurement is related to EVM because EVM measures the vector difference between the measured and ideal signals, while ρ measures the correlation between the two signals. The value of ρ can range from 0.0 to 1.0. The following table illustrates the ranges for ρ and degree of correlation between measured and ideal signals.