PCM Data Reliability Monitoring Through Estimation of Signal-to-Noise Ratio

Reliability monitoring of digital pulse-code modulation (PCM) data in coherent transmission systems can be based upon online estimation of signal-to-noise ratio (SNR) at the receiver. Maximum likelihood SNR estimation is analyzed to determine the structure of the estimator and its ability to monitor error rates with a given degree of confidence. In particular, relationships between estimation confidence intervals, observation time, word error rates, and PCM word structure are developed.