US 2006/0039485 A1 · Pattern position measuring device, method, and program, and record medium on which the program is recorded

Abstract

The position of a specific pattern such as known symbol in a signal such as an OFDM signal is estimated with high accuracy. An effective symbol extraction section (12) extracts a known symbol (preamble) as an effective symbol from a signal to be measured according to an approximate position of the known symbol. A mixer (20) determines the product of the frequency spectrum of the extracted effective symbol by the result of the conversion performed by a complex conjugate conversion section (16) from the frequency spectrum of the known symbol into the conjugate complex. A phase shift amount measuring section (26) measures the phase shift amount Δθ of the product determined by the mixer (20). A precision pattern position measuring section (28) measures the difference between the position of the known symbol and its approximate position on the basis of the phase shift amount. Since the phase shift amount Δθ itself precisely indicates the position of the known symbol of the signal to be measured, the position of the known symbol can be precisely measured.

Claims14

Dependent claims

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;
and
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.

2 more elements

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 the 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 predetermine pattern;
and
said pattern extraction element starts the extraction of the predetermined pattern from the signal to be measured within the guard interval.

10 more elements

Dependencies are inferred from the claim text.

Pattern position measuring device, method, and program, and record medium on which the program is recorded

Life of this patent

Pattern position measuring device, method, and program, and record medium on which the program is recorded

Life of this patent

Abstract

Claims14