Patent ID: 8166354

Claim:
Apparatus for estimating a bit error rate at a receiver that receives a sequence of digital data from a digital transmission and generates a sequence of decision values, each decision value representing a confidence level associated with a decided symbol value, the confidence level representative that the decided symbol value is correctly decided, said apparatus comprising: a threshold selector configured to select a selected threshold; a detector adapted to receive a decision value and said selected threshold, said detector configured to detect whether the decision value is less than the selected threshold, indicative of a low confidence level of correctness of the decided symbol value; and an accumulator adapted to receive indication of detections made by said detector, said accumulator configured to maintain a count of detections indicative of decision values that are less than the selected threshold during the sequence of digital data from the digital transmission and to increment said maintained count each time in which the decision detected by said detector is indicative of the low confidence level and to provide said maintained count for formation of a bit error rate estimation of the sequence of the digital data from an adjustable total number that is proportional to the processed bits from the digital transmission.