US 8,300,621 B2 · System and method for timing acquisition and carrier frequency offset estimation in wireless communication based on OFDM

Abstract

The present invention relates to a method for timing acquisition and carrier frequency offset estimation of an OFDM communication system and an apparatus using the same. For this purpose the present invention provides a method for calculating at least one auto-correlation and calculating an observation value by performing a sliding sum on the at least one auto-correlation, and calculating a peak point of an absolute value of the observation as frame timing. In addition, the present invention provides a method for generating a third OFDM symbol that is generated by delaying a second OFDM symbol, calculating an observation value through the second and third OFDM symbols, and calculating a phase difference from a result of multiplication of the observation value and a conjugate complex value of the observation value such that a carrier frequency offset can be estimated. According to the present invention, the number of OFDM symbols is sufficient for obtaining timing acquisition with high reliability, and the offset estimation algorithm having a lower implementation complexity is provided such that superior performance is expected and carrier frequency offset with high reliability can be achieved.

Claims13

Dependent claims

A timing acquisition apparatus that calculates frame timing by using an orthogonal frequency division multiplexing (OFDM) symbol input to a terminal of an OFDM system, the timing acquisition apparatus comprising:

a delay signal generator, comprising:
a first tab shift register for storing the input OFDM symbol;
a delay generator for delaying the input OFDM symbol from the first tab shift register by a length of a repeating pattern of input the OFDM symbol to generate a second OFDM symbol, wherein the input OFDM symbol and the second OFDM symbol are conjugate complex symmetric;
and
a second tab shift register for storing the second OFDM symbol;
an operation unit for calculating an observation value resulting from auto-correlation of the input OFDM symbol from the first tab shift register and the second OFDM symbol from the second tab shift register;
and
a peak value checking device for calculating the frame timing by checking a peak point of an absolute value of the observation value.

5 more elements

A method for calculating frame timing by using an orthogonal frequency division multiplexing (OFDM) symbol input to a terminal of an OFDM system, the method comprising:

(a) receiving, at the terminal, at least one OFDM symbol from a base station, and storing the at least one OFDM symbol in a first tab shift register;
(b) generating, by a delay signal generating unit, a second OFDM symbol by delaying the at least one received OFDM symbol from the first tab shift register by a length of a repeating pattern of the at least one received OFDM symbol,
wherein the delay signal generating unit stores the at least one received OFDM symbol in the first tab shift register and stores the second OFDM symbol in a second tab shift register, and
wherein the at least one received OFDM symbol and the second OFDM symbol are conjugate complex symmetric;
(c) calculating, by an operation unit, at least one auto-correlation by operating the at least one received OFDM symbol from the first tab shift register and the second OFDM symbol from the second tab shift register;
and
(d) outputting, from an absolute value calculator, a peak point of an absolute value of an observation value resulting from the at least one auto-correlation as the frame timing.

4 more elements

Dependencies are inferred from the claim text.

System and method for timing acquisition and carrier frequency offset estimation in wireless communication based on OFDM

Life of this patent

System and method for timing acquisition and carrier frequency offset estimation in wireless communication based on OFDM

Life of this patent

Abstract

Claims13