A method for estimating an SNR-related parameter, such as ES/N0, from one or more symbols. The number of symbols within a predetermined number of symbols that fall within one or more collection areas is counted. The count is then associated with a value of the SNR-related parameter. This association may be performed through one or more lookup tables. In one application, a scaling factor is derived from the count. The scaling factor may be used to scale symbols before they are quantized and inputted into a trellis decoder such as a log-MAP decoder.