Panasonic Corporation

Sun Patent Trust

Panasonic Intellectual Property Management Co., Ltd.

Isuzu Glass Company, Ltd.

Panasonic Intellectual Property Corporation of America

Isuzu Glass Ltd.

Yoshinobu Matsumura

Tomohiro Kimura

Mikihiro Ouchi

Ippei Kanno

Teruaki Hasegawa

Shigeru Soga

Hisateru Kobatake

Kouya Watanabe

Hideki Nakahara

Tomohiko Taniguchi

Yoshio Urabe

Kenichi Mori

Naoya Tokunaga

Kohei Kadono

Toshihiko Einishi

Tatsuya Suetsugu

Naoko Kaga

Kunihiko Tani

Maki Tanigawa

Takeshi Morihara

Kiyoshi Shinohara

Mariko Murakami

An OFDM transmitter and an OFDM receiver respectively transmit and receive N (N≥2, N is an integer) control symbols. For each control symbol, a guard interval time-domain signal is, for example, identical to a signal obtained by frequency-shifting at least a portion of a useful symbol time-domain signal by an amount different from any other symbol, or to a signal obtained by frequency-shifting one or both of a portion and a span of a useful symbol interval time-domain signal different from any other symbol by a predetermined amount.

OFDM transmitter device having a symbol generator for generating non-zero control symbols, and OFDM transmission method including generating non-zero control symbols

An OFDM transmitter and an OFDM receiver respectively transmit and receive N (N&#x2265;2, N is an integer) control symbols. For each control symbol, a guard interval time-domain signal is, for example, identical to a signal obtained by frequency-shifting at least a portion of a useful symbol time-domain signal by an amount different from any other symbol, or to a signal obtained by frequency-shifting one or both of a portion and a span of a useful symbol interval time-domain signal different from any other symbol by a predetermined amount.

Provided is an OFDM reception apparatus that can reduce, even in an environment where the influence of noises is strong, this influence of the noises, thereby improving the precision of detecting a carrier frequency error. In this apparatus, a filtering unit () receives received signals each including a short preamble (STF) in which a plurality of pilot subcarriers are intermittently arranged in the frequency domain and repeatedly arranged in the time domain, and the filtering unit () attenuates the frequency components between respective two adjacent ones of the plurality of pilot subcarriers in the frequency domain. A correction unit () corrects a carrier frequency error of the received signal on the basis of the signals of the plurality of pilot subcarriers having passed through the filtering unit ().

Reception apparatus and frequency error correction method

A preamble generating unit generates first and second synchronization preambles having different numbers of subcarriers. A transmission signal generating unit generates an OFDM transmission signal through time-division multiplexing by using the generated first and second synchronization preambles. A transmission RF unit converts the generated OFDM transmission signal into a radio-frequency OFDM signal and transmits the radio-frequency OFDM signal. The preamble generating unit adds a predetermined dummy period between the first synchronization preamble and the second synchronization preamble.

Transmitter, receiver, transmission method, and reception method

An OFDM receiver apparatus () receives a signal that includes an STF having a plurality of pilot subcarriers and a plurality of null subcarriers that are alternately arranged at predetermined frequency intervals in a transmission band and that includes a data part that is time-multiplexed with the STF. A null carrier extraction unit () extracts a plurality of null subcarrier frequency signals from the received signal. A power calculation unit () detects, based on the levels of the extracted signals, the interference levels of the plurality of subcarriers in the transmission band. A soft decision unit () uses the reliability of the plurality of subcarriers, which is calculated based on the detected interference levels, to perform a soft decision of a demodulated signal of the received data part. An error correction unit () performs, based on the result of the soft decision, an error correction, thereby reconstructing the data.

Receiver apparatus and frequency selectivity interference correction method

An interfering wave is detected using, in a received signal including a preamble and a control signal field, a plurality of symbols including a symbol configuring the preamble and a symbol configuring the control signal field. The received signal has one of a plurality of transmission formats that use at least either a first frequency band or a second frequency band. In a signal quality detector, a symbol differential calculator calculates, in each of the first frequency band and the second frequency band, differences between a certain number of symbols adjacent to one another at predetermined positions in a time domain among the plurality of symbols. A square operator performs square operations on results of the calculation of differences. An interference determiner determines, using results of the square operations, whether each of the first frequency band and the second frequency band includes an interfering wave.

Radio communication apparatus and radio communication method

A tuner receives a received signal using one of a plurality of transmission formats that use at least one of either a first frequency or a second frequency band. A determination unit determines the transmission format being used in the received signal from among the plurality of transmission formats. In the determination unit, a pattern matching unit stores in advance a plurality of patterns respectively expressing a received waveform of a preamble in each of the plurality of transmission formats, conducts a pattern matching process between the received signal and the each of the plurality of patterns, and obtains a correlation value. A transmission mode determination unit determines the transmission format being used in the received signal on the basis of the correlation value.

Wireless communication device and wireless communication method

An OFDM reception device including: a first orthogonal transformation unit that orthogonally transforms a signal for a useful symbol duration included in an OFDM signal and outputs a resulting orthogonally transformed signal; a second orthogonal transformation unit that orthogonally transforms a signal for a guard interval duration included in the OFDM signal and outputs a resulting orthogonally transformed signal; a detection unit that detects a wide band carrier frequency error amount according to the signal output from the first orthogonal transformation unit and the signal output from the second orthogonal transformation unit; and a correction unit that corrects a wide band carrier frequency shift of the OFDM symbol according to the wide band carrier frequency error amount detected by the detection unit.

OFDM reception device, OFDM reception circuit, OFDM reception method, and OFDM reception program

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Osaka, Japan

Yoshinobu Matsumura