Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Shigeru Soga

Ippei Kanno

Yoshinobu Matsumura

Teruaki Hasegawa

Hisateru Kobatake

Kouya Watanabe

Shunsuke Sakai

Yoshio Urabe

Kenichi Mori

Haruka Takano

A radar apparatus includes: a transmitting antenna; a receiving antenna; transmitting circuitry; receiving circuitry; a storage; and control circuitry which selects one of a plurality of spread codes. A radar signal includes a plurality of periodic frames. Each of the frames includes first and second segments. The first segment includes a first spread signal which is obtained by multiplication of a predetermined reference signal by at least a part of the selected spread code. The second segment includes a second spread signal which is obtained by multiplication of the identification code by at least the part of the selected spread code. The control circuitry calculates a first correlation value between a received radar signal and the first spread signal, calculates a second correlation value between the received radar signal and the second spread signal, and selects another one of the plurality of spread codes on a basis of temporal positions and magnitudes of peaks of the first and second correlation values in each frame.

Radar apparatus including transmitting antenna and receiving antenna

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

There is provided a diversity receiving apparatus, comprising: a first branch () for decoding a frequency multiplexing signal in which a carrier group has been multiplexed, thereby outputting a first data carrier and a first pilot carrier; a second branch () for decoding a frequency multiplexing signal in which a carrier group has been multiplexed, thereby outputting a second data carrier and a second pilot carrier; a timing adjusting unit () for synchronizing processing timing for a carrier group decoded by the first branch () and a carrier group decoded by the second branch (); a combining/selecting unit () for combining/selecting the first data carrier and/or the second data carrier; and a control unit () for controlling stopping and starting operation of at least one of the first branch () and the second branch () according to at least one of a receiving status of the first branch () and a receiving status of second branch ().

Diversity receiving apparatus and diversity receiving method

There is provided a diversity receiving apparatus () that comprises: a receiving unit () for receiving a frequency-division multiplexing signal on which a carrier group is multiplexed; a first demodulating unit () for outputting a first data carrier and a first transmission control carrier; a second demodulating unit () for outputting a second data carrier and a second transmission control carrier; a timing adjusting unit () for synchronizing processing timing of the first demodulating unit () and the second demodulating unit (); a first combining/selecting unit () for combining or selecting a first transmission control carrier and a second transmission control carrier; a second combining/selecting unit () for combining or selecting a first data carrier and a second data carrier; a decoding unit () for decoding a transmission control signal using the transmission control carrier selected by the first combining/selecting unit (); and a detecting unit () for detecting frame synchronization.

An amplitude error compensating device comprises an amplitude correcting section for performing amplitude correction with respect to an in-phase component and a quadrature component of a complex signal obtained by quadrature demodulation, based on amplitude error information, and outputting a resultant amplitude-corrected complex signal, and an amplitude error detecting section for obtaining the amplitude error information, depending on amplitudes of an in-phase component and a quadrature component of the amplitude-corrected complex signal. The amplitude error detecting section comprises a power difference calculating section for obtaining as a power error a difference in power between the in-phase component and the quadrature component of the amplitude-corrected complex signal, a rotation detecting section for detecting a rotation of a signal point of the amplitude-corrected complex signal, an error information control section for outputting the power error when a rotation of the signal point has been detected, and 0 when a rotation of the signal point has not been detected, and a smoothing section for smoothing an output of the error information control section, and outputting the result as the amplitude error information.

Amplitude error compensating device and quadrature skew error compensating device

In a timing component extractor for a digital modulated signal, a frequency converting sectionreceives a complex baseband signal having a symbol rate fs and formed from an I signal and a Q signal, and converts frequency components &#xb1;fs/2, which are present in the complex baseband signal as the data changes, to frequency components &#xb1;fs/4. The I signal and Q signal of the complex baseband signal are then nonlinearly processed. In other words, multiplierssquare the I signal and the Q signal, respectively, and an adderadds the respective results of the multipliers. A BPFextracts the frequency components &#xb1;fs/2 from the output of the adder, and outputs the extracted frequency components &#xb1;fs/2 as a timing signal. Accordingly, processing can be conducted at a sampling frequency which is twice the symbol rate fs. Moreover, timing extraction can be stably conducted without being affected by a carrier frequency offset.

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Hyogo, Japan

Shigeru Soga