Patent ID: 7558327

Claim:
A pattern position measuring device that measures a position of a predetermined pattern in a signal to be measured, comprising: a pattern extraction element that extracts the predetermined pattern as an effective pattern from the signal to be measured based on an approximate position of the predetermined pattern; a spectrum product determining element that determines a product of a frequency spectrum of the effective pattern and data based on a frequency spectrum of the predetermined pattern; a phase shift amount measuring element that measures a phase shift amount of the product determined by said spectrum product determining element; a precision pattern position measuring element that measures a difference between the position of the predetermined pattern and the approximate position of the predetermined pattern based on the phase shift amount; a complex conjugate conversion element that converts the frequency spectrum of the predetermined pattern to a conjugate complex; a first fast Fourier transform element that applies fast Fourier transform to the effective pattern so as to output the frequency spectrum of the effective pattern; and a second fast Fourier transform element that applies fast Fourier transform to the predetermined pattern so as to output the frequency spectrum of the predetermined pattern, wherein: said spectrum product determining element determines a complex product of the frequency spectrum of the effective pattern extracted by said pattern extraction element and a conversion result of said complex conjugate conversion element; the signal to be measured has a guard interval positioned prior to the predetermined pattern; and said pattern extraction element starts the extraction of the predetermined pattern from the signal to be measured within the guard interval.