Patent ID: 8290143

Claim:
A method for estimating a delay of a signal between a reference point and a reception point, the method comprising the steps of: defining at least one quantity of said signal; and for each quantity, performing the steps of: evaluating the quantity at the reference point and at the reception point at a plurality of time instants, thereby yielding reference-point values and reception-point values, respectively; quantizing the reference-point values by comparing each of said reference-point values with a first time-invariant threshold and quantizing the reception-point values by comparing each of said reception-point values with a second time-invariant threshold, thereby yielding quantized reference-point values and quantized reception-point values, respectively; storing the most recent quantized reference-point values and the most recent reception-point values; assigning a penalty to each of all possible pairs of quantized values, each pair consisting of a quantized reference-point value followed by a quantized reception-point value, said penalty being based on an expected probability of simultaneous occurrence of the values of said pair when the delay is correctly estimated; for each candidate delay from a set of candidate delays, each expressed as a multiple of the time-distance between consecutive time instants, computing an average penalty by averaging the penalties of a plurality of pairs of stored quantized values, each pair including a stored quantized reference-point value evaluated at a first time instant followed by a stored quantized reception-point value evaluated at a second time instant, wherein the first and the second time instants are time-shifted by the candidate delay; and electing an estimated delay from the set of candidate delays based on the computed average penalties, wherein a first constant penalty is assigned, for a particular quantity, to the simultaneous occurrence of a high quantized reference-point value and a low quantized reception-point value, and a second penalty is assigned to all other occurrences, wherein the first penalty is greater than the second penalty.