Bit error rate estimator which uses soft decisions from an equaliser and path metric data

摘要

An initial estimate of the number of errors contained within a frame, n_err, is produced using first empirical values [ g or a and b ] and the magnitude of soft decisions output from the equaliser (see equations 2 and 3 for example). This initial value is then compared with a dynamic threshold which is determined using, inter alia, path metric information from a Viterbi decoder. Depending on the result of the threshold comparison the initial estimate is accepted as the final estimate of signal quality, or is refined using second empirical values Ci. BER is then deduced from n_err.