Abstract: A method and apparatus for digitizing a repetitive signal having a long pattern length is provided. The method comprises the steps of determining a clock period to be used when sampling the repetitive signal and determining a frame period of the repetitive signal. Thereafter, a sampling period is selected that is a relatively prime integer when compared with the clock period and frame period. The sampling period also comprises an integer number of time resolution periods, so that when sampling is performed in accordance with the sampling period, all time resolution periods are sampled at a same relative time position thereof.