OFDM signal receiver and method for receiving OFDM signal
View Patent ↗A Tu delay section ( 110 ) delays an analog-to-digital converted OFDM signal S 01 by a time corresponding to an effective symbol period Tu. A correlation signal of an output of the Tu delay section ( 110 ) and OFDM signal S 01 is obtained using a correlation calculating section ( 120 ). A delay section ( 130 ) outputs at least one delayed correlation signal obtained by delaying a correlation signal S 02 . Next, an adding section ( 140 ) performs addition of the correlation signal S 02 and the delayed correlation signal, and then an interval integration section ( 150 ) performs transfer integration over a definite interval on a result of the addition. Then, a symbol period smoothing section ( 160 ) smoothes a result of the transfer integration for an interval of the effective symbol period of the OFDM signal S 01 , and then a window position detection section ( 170 ) calculates window position information from an output of the symbol period smoothing section ( 160 ).
1. An OFDM signal receiver comprising:
a first delay section for receiving an analog-to-digital converted OFDM signal as an input and for delaying the OFDM signal by a time corresponding to an effective symbol period Tu of the OFDM signal and outputting the delayed signal;
a correlation calculating section for outputting a correlation signal showing a correlation between the output of the first delay section and the OFDM signal;
a second delay section for outputting at least one delayed correlation signal obtained by delaying the correlation signal;
an adding section for performing addition of the correlation signal and the at least one delayed correlation signal;
an interval integration section for outputting an integration signal showing a result of transfer integration over a definite interval performed on an output of the adding section;
a symbol period smoothing section for smoothing the integration signal for an interval of the effective symbol period of the OFDM signal; and
a window position detection section for calculating window position information from an output of the symbol period smoothing section.
2. The OFDM signal receiver of claim 1 , further comprising:
a first gain adjustment section for adjusting a gain of the correlation signal; and
a second gain adjustment section for adjusting a gain of the at least one delayed correlation signal,
wherein the adding section performs addition of the correlation signal whose gain is adjusted and the at least one delayed correlation signal whose gain is adjusted.
3. The OFDM signal receiver of claim 1 , wherein
the second delay section delays the output of the correlation calculating section by a time corresponding to a guard interval period Tg of the OFDM signal, and
the interval integration section performs transfer integration over a period of three times the guard interval period Tg of the OFDM signal on the output of the adding section.
4. The OFDM signal receiver of claim 1 , wherein the window position detection section calculates the window position information on the basis of a point in which the output of the symbol period smoothing section is maximum.
5. A method for receiving an OFDM signal comprising:
a first delay step of receiving an analog-to-digital converted OFDM signal as an input and of delaying the OFDM signal by a time corresponding to an effective symbol period Tu of the OFDM signal and outputting the delayed signal;
a correlation calculating step of outputting a correlation signal showing a correlation between the output of the first delay step and the OFDM signal;
a second delay step of outputting at least one delayed correlation signal obtained by delaying the correlation signal;
an adding step of performing addition of the correlation signal and the at least one delayed correlation signal;
an interval integration step of outputting an integration signal showing a result of transfer integration over a definite interval performed on an output of the adding step;
a symbol period smoothing step of smoothing the integration signal for an interval of the effective symbol period of the OFDM signal; and
a window position detection step of calculating window position information from an output of the symbol period smoothing step.