US 7,394,859 B2
OFDM signal receiving apparatus and an OFDM signal receiving method
Jun Mitsugi, Yokohama (Japan)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan)
Filed on Aug. 17, 2004, as Appl. No. 10/919,396.
Claims priority of application No. 2003-297816 (JP), filed on Aug. 21, 2003; and application No. 2004-232685 (JP), filed on Aug. 09, 2004.
Prior Publication US 2005/0105461 A1, May 19, 2005
Int. Cl. H04K 1/10 (2006.01)
U.S. Cl. 375—260 15 Claims
OG exemplary drawing
 
1. An apparatus for receiving an OFDM (Orthogonal Frequency Division Multiplexing) signal multiplexing a reference symbol having known amplitude and phase characteristic to at least one of a plurality of sub-carriers orthogonal to each other, comprising:
a converter which converts the OFDM signal into a plurality of sub-carriers;
an extraction circuit to extract the reference symbol from at least one of a plurality of sub-carriers;
an estimation circuit to estimate a transmission channel distortion for each of the sub-carriers based on the known amplitude and phase characteristic of the reference symbol to obtain a plurality of channel estimation results;
an estimation processing circuit which adds the channel estimation results every several sub-carriers of the sub-carriers to obtain a plurality of added values, the several sub-carriers including a first sub-carrier corresponding to the at least one of the several sub-carriers, a second sub-carrier adjacent to a high-band side of the first sub-carrier and a third sub-carrier adjacent to a low-band side of the first sub-carrier;
a calculating unit configured to obtain amplitude and phase correction values on the first sub-carrier by averaging the added results, while the first sub-carrier is shifted sequentially;
a correction circuit to correct amplitude and phase of each of the plurality of sub-carriers based on the amplitude and phase correction values; and
wherein the estimation processing circuit multiplies the result of the first sub-carrier, the result of the second sub-carrier, and the result of the third sub-carrier by respective weight coefficients, and adds the multiplied values.