Error rate measurement apparatus and error rate measurement method

An error rate measurement apparatus that measures an error rate of an input signal from a device under test, the error rate measurement apparatus comprising:

• a processing unit that calculates a measurement time satisfying a target confidence level based on the target confidence level, a data rate of the input signal, a target error rate of the input signal, and an assumed number of errors E during the measurement time of the input signal,
• wherein the processing unit includes
• an average value calculation unit that calculates a sum x of a value obtained by dividing a variable min_x by 2 and a value obtained by dividing a variable max_x by 2,
• a provisional confidence level calculation unit of calculating a provisional confidence level CLx based on the sum x according to the expression:
• CLx
• =
• e
• -
• x
• ×
• ∑
• k
• =
• 0
• E
• x
• k
• k
• !
• ,
• an upper and lower limit value update unit that substitutes the sum x for the variable min_x in a case where the provisional confidence level CLx is equal to or lower than the target confidence level, and substitutes the sum x for the variable max_x in a case where the provisional confidence level CLx is higher than the target confidence level,
• a convergence determination unit that determines whether or not changes in a value of the sum x calculated by the average value calculation unit are converged in a predetermined range, and
• a measurement time calculation unit that calculates, in a case where the convergence determination unit determines the convergence, a value obtained by dividing the converged sum x by a product of the data rate and the target error rate, as the measurement time, and
• the processing unit repeats processing of the average value calculation unit, the provisional confidence level calculation unit, and the upper and lower limit value update unit by using a latest variable min x and a latest variable max_x in a case where the convergence determination unit does not determine the convergence.