Presented herein are pilot-less noise estimation techniques that utilize a correlation between attributes of a received signal and the noise to generate signal-to-noise ratio (SNR) estimate for the signal. More specifically, an interval of a digital signal is received a log-likelihood ratio (LLR) value is calculated for a plurality of bits in the interval of the signal. A scalar value that relates to a distribution of the calculated LLR values is computed. The SNR for the interval of the signal is determined based on a predetermined correlation between the scalar value and noise within the received interval of the signal.