US 6,983,027 B2 | ||
OFDM transmit signal receiver | ||
Takashi Seki, Yokohama (Japan); and Takeshi Koyama, Chigasaki (Japan) | ||
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
Filed on Nov. 16, 2001, as Appl. No. 9/987,881. | ||
Claims priority of application No. 2000-351611 (JP), filed on Nov. 17, 2000. | ||
Prior Publication US 2002/0061076 A1, May 23, 2002 | ||
Int. Cl. H03K 9/00 (2006.01) |
U.S. Cl. 375—316 | 20 Claims |
1. An OFDM transmit signal receiver comprising:
a demodulation circuit configured to receive an OFDM transmit signal containing an information carrier, an additive-information
transmission carrier, and a reception-synchronization pilot signal to convert said information carrier, said additive-information
transmission carrier, and said reception-synchronization pilot signal into frequency-axial data, said information carrier
transmitting information data, said additive-information transmission carrier having a lower multi-valued modulation degree
than said information carrier, and said reception-synchronization pilot signal having a lower multi-valued modulation degree
than said information carrier;
a differential detection circuit configured to conduct detection using a detection-subject symbol of a plurality of symbols
indicated at a predetermined interval in the same frequency range and using a symbol ahead said detection-subject symbol by
a predetermined time in at least either one output of said additive information transmission carrier and said reception-synchronization
pilot signal output from said demodulation circuit; and
a first S/N ratio generation circuit configured to generate an S/N ratio based on a detection output provided from said differential
detection circuit, said S/N ratio indicating a reception quality of said OFDM transmit signal.
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