| US 7,483,503 B2 | ||
| Wireless communication using a plurality of antennas | ||
| Yoshimasa Egashira, Kawasaki (Japan); Daisuke Takeda, Kawasaki (Japan); Tsuguhide Aoki, Kawasaki (Japan); and Yasuhiko Tanabe, Kawasaki (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Jun. 08, 2005, as Appl. No. 11/147,321. | ||
| Claims priority of application No. 2004-171669 (JP), filed on Jun. 09, 2004. | ||
| Prior Publication US 2005/0276349 A1, Dec. 15, 2005 | ||
| Int. Cl. H04B 7/02 (2006.01); H04B 7/08 (2006.01); H04L 1/02 (2006.01); H04L 27/00 (2006.01) | ||
| U.S. Cl. 375—347 [375/299; 375/267; 455/132] | 10 Claims |
| 7. A wireless communication apparatus comprising:
receiving unit configured to receive a known symbol sequence and subsequent data symbols transmitted by a plurality of antennas,
the known symbol sequence including a plurality of known symbols ordered in time, each of the known symbols having plural
subcarriers on which plural known values are carried on, the known symbols including (a) at least one inverted known symbol
in which a phase of one of two known values carried on two subcarriers adjacent in frequency domain is inverted and a phase
of the other of the two known values is not inverted, and (b) at least one non-inverted known symbol in which neither of phases
of the two known values carried on the two subcarriers adjacent in frequency domain is inverted, time positions of the inverted
known symbol and the non-inverted known symbol in the known symbol sequence being determined in accordance with the number
of the known symbols in the known symbol sequence;
a first calculating unit configured to calculate a channel estimation value corresponding to each of the subcarriers, from
each known symbol received;
a second calculating unit configured to calculate, for each known symbol, a correlation value between two channel estimation
values corresponding to the two subcarriers adjacent in frequency domain, to obtain a positive correlation value in the case
of the non-inverted known symbol and to obtain a negative correlation value in the case of the inverted known symbol;
an estimating unit configured to estimate the number of antennas, by counting the number of the known symbols received up
to the last known symbol in the known symbol sequence, the last known symbol having one of the positive and the negative correlation
values, and the known symbols other than the last known symbol in the known symbol sequence having the other of the positive
and the negative correlation values; and
a processing unit configured to process the data symbols received by using the each channel estimation value and the number
of antennas estimated.
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