Presented herein are non-disruptive noise estimation techniques that utilize a correlation between attributes of a received signal and the noise to generate estimated noise values for symbols of the signal. More specifically, a digital signal comprising symbols transmitted over a telecommunications network is received. For each of a plurality of the symbols, an estimated noise value associated with the respective symbol is generated through a correlation of a log-likelihood ratio (LLR) value to predetermined noise values. The estimated noise values for the plurality of symbols are used to generate noise information representing time and frequency characteristics of noise in the telecommunications network.