Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Corporation of America

National Institute of Information and Communications Technology, Incorporated Administrative Agency

Wi-Fi One, LLC

Ryuji Kohno

Katsuaki Abe

Akihiko Matsuoka

Masayuki Orihashi

Yutaka Murakami

Kentaro Miyano

Noriaki Saito

Yoshifumi Hosokawa

Takenori Sakamoto

Makoto Hasegawa

Shinichiro Takabayashi

Yasuyuki Naito

Masahiro Mimura

Tomoya Urushihara

Hiroshi Katayama

Katsushi Yokozaki

Takaaki Kishigami

Kenichi Takahashi

Yoshito Shimizu

Job Cleopa Msuya

Kiyotaka Kobayashi

Michiaki Matsuo

Toshiyuki Tsumura

Yasumi Imagawa

Satoshi Tsukamoto

Yoichi Yamaki

Kiyomichi Araki

Kazunori Watanabe

Junji Sato

Tadashi Morita

Morikazu Sagawa

Naoyuki Yamamoto

Yohei Morishita

Masayoshi Yoneyama

Toshifumi Tsutsumi

Shokichi Toyokawa

Tsuneo Hikokubo

Yukio Oishi

Hitoshi Shirakura

Masayuki Orihasi

Motoko Taniguchi

Naoyuki Yamamot

Schinichiro Takabayashi

A communication apparatus includes a reference signal generating section, a transmitting section, a propagation estimating section, a first data acquiring section, and a decoding section. The reference signal generating section generates a first reference signal to enable a communicating party to estimate a propagation environment. The transmitting section transmits the first reference signal. The propagation estimating section estimates a first propagation estimation value of the propagation environment using a second reference signal transmitted from the communicating party. The first data acquiring section generates first data using the first propagation estimation value. The decoding section decodes a transmission signal encoded using a second propagation estimation value that is estimated by the communicating party using the first reference signal, to obtain second data using the first data.

Communication apparatus and communication system

A transmission frame generating device generates a transmission frame. The generating device includes a control information signal generator which generates a modulation method control signal indicating a modulation method used for a data signal and an error correction method control signal indicating an error correction method used for the data signal and a frame former which forms the transmission frame by arranging a training signal, the data signal, the modulation method control signal and the error correction method control signal on a plurality of subcarriers on a frequency axis. The modulation method control signal being repeatedly and discretely arranged on a first multiple of the plurality of subcarriers on the frequency axis and the error correction method control signal being repeatedly and discretely arranged on a second multiple of the plurality of the subcarriers on the frequency axis.

Transmitting apparatus, receiving apparatus, transmission method, and reception method

A transmitting apparatus, includes a signal generator that generates a modulation signal by modulating transmission data using one of a plurality of modulation schemes, a first modulation scheme having a higher m-ary modulation value than other modulation schemes and a pilot signal generator generates a pilot signal. An orthogonal frequency division multiplexing (OFDM) signal generator generates an OFDM signal by selecting the modulation signal and the pilot signal according to the frame timing signal. The OFDM signal is converted to a radio signal, is amplified and is transmitted to an antenna. The pilot signal is inserted in the OFDM signal per a predetermined OFDM symbol and per a predetermined subcarrier and has a lower amplitude than a maximum amplitude of the first modulation scheme in an in-phase-quadrature (IQ) plane.

Radio communication apparatus capable of switching modulation schemes

A transmission frame generating device includes a control information signal generator and a frame former. The control information signal generator generates a modulation method information signal indicating a modulation method of a data signal and an error correction method information signal indicating an error correction method of the data signal. The frame former forms the transmission frame by repeating and discretely arranging the same modulation method information signal on a first multiple of a plurality of subcarriers on a frequency axis and by repeating and discretely arranging the same error correction method information signal on a second multiple of the plurality of the subcarriers on the frequency axis.

In a communication system in which propagation path error tolerance is improved by switching the modulation method or error correction method adaptively according to the state of the propagation path, signals MX, MY, CX, and CY indicating the modulation method and error correction method used by the transmitting side are transmitted arranged at discrete locations within the same frame. By this means, the possibility of discretely arranged signals MX and MY, or CX and CY, both degrading is made low even if the transmit signal experiences fading or propagation path fluctuations. As a result, it is possible for the modulation method information signal and/or error correction method information signal to be restored correctly on the receiving side.

Variation in received signal qualities at positions in a frame is estimated so as to improve a communication quality. In communication from a transmitting station to a receiving station, a received signal quality is estimated per data position in a data frame received by the receiving station, thus to grasp situations of the received signal quality varied depending on a position which is caused by various factors of property deterioration in a process from transmitting communication data from the transmitting station to receiving it by the receiving station via a transmission path. Further, an estimating result is supplied to a data processing unit and used at a latter stage. The estimating result is notified to the transmitting station and arrangement of transmitting data is reconstructed on the transmitting station side. The arrangement of the transmitting data is properly changed in accordance with importance of the communication data. Further, the rearranged transmitting data is properly restored on the receiving station side, thereby obtaining received data and improving a quality of a communication service.

Reception method and reception device estimating reception quality and communication system using the reception device

A sampling filter device wherein the filter characteristic is variable without using a control signal of a complicated waveform is provided. A sampling filter devicehas integration capacitorsand, an integration time adjustment section, and a plurality of switches, and. Input current is integrated in different time duration with one clock and is stored in the integration capacitorsandand charges stored in the integration capacitor from several clocks before to one clock before are added and the result is output. When charge is stored in the integration capacitorsandwith each clock, the integration time duration is changed, whereby it is made possible to weight and add output charge and the filter characteristic changes.

Sampling filter device

Disclosed are a nonlinear distortion compensating receiver and nonlinear distortion compensation method, wherein nonlinear distortion is reduced with a simple circuit configuration. A correction (opposite characteristics) filter () has characteristics opposite that of the frequency characteristics of a direct sampling mixer () and corrects signals sampled by the direct sampling mixer (). In the main path, a LPF () extracts a frequency band component of a desired signal from the corrected signal. In the replica path, a BPF () extracts the frequency band component of a blocker signal from the corrected signal. A cubing circuit () uses the frequency band component of the blocker signal to generate a replica signal for the nonlinear distortion. An adaptive filter () performs filter processing on the replica signal while updating the filter coefficients. A subtractor () subtracts the output signal of the adaptive filter () from the frequency band component of the extracted desired signal and outputs the subtraction result as the desired signal.

Nonlinear distortion compensating receiver and nonlinear distortion compensation method

An orthogonal frequency division multiplexing transmission method includes generating a data symbol. A control information signal is generated. The control information signal relates to a modulation scheme and an error correction scheme of a data symbol in a frame. An orthogonal frequency division multiplexing signal is formed. The orthogonal frequency division multiplexing signal includes the data symbol and the control information signal. The orthogonal frequency division multiplexing signal is formed by arranging the control information signal in a first symbol group that is formed with subcarriers in a time period, and in a second symbol group that is formed with subcarriers, located in the time period, and that has a frequency band distant from the first symbol group.

A multimode wireless communication apparatus that supports plural wireless communication systems and switches wireless communication systems to communicate. The apparatus includes a signal processor capable of switching wireless communication systems by plural manners; and a controller that directs to the signal processor a combination of manners of switching wireless communication systems according to a communication environment. The signal processor switches wireless communication systems according to the combination of manners of switching wireless communication systems directed from the controller.

Multimode wireless communication apparatus and wireless communication method

A wireless terminal involving small redundancy that can be reconfigured to a configuration compatible with a plurality of systems using the hardware resources compatible with one system is provided. A wireless terminalA is compatible with an OFCDM system and has a signal processing section, a synchronous detection section, etc. The signal processing sectionperforms Fourier transform when the wireless terminal is compatible with the OFCDM system; the signal processing sectionperforms Fourier transform and inverse Fourier transform compatible with an OFDM system when the wireless terminal is compatible with the OFDM system and a CDMA system. When the wireless terminal is compatible with the OFCDM system, the synchronous detection sectionuses taps used in the systems when the wireless terminal is compatible with the OFDM system and the CDMA system. When the wireless terminalA is placed out of the area in the OFCDM system, it is switched to a configuration compatible with the OFDM system and the CDMA system.

Wireless terminal and communication system switching method

Provided are a direct sampling circuit and a receiver using a discrete time analog process and having a filter effect of a steep attenuation characteristic in a narrow-pass band without lowering a sampling rate. In a discrete time direct sampling circuit (), the positive phase side and the inverse phase side are both sampled by a local signal for a differential current output of a differential voltage/current conversion unit () and electric charge is accumulated in a charge sampling capacitor. The latest accumulated charge at the positive phase side and charge accumulated at the inverse phase side before a predetermined number of samples are combined with the charge accumulated in a history capacitor () in the past. Thus, it is possible to realize equivalently high-degree FIR filter characteristic.

Discrete time direct sampling circuit and receiver

There are provided a sampling filter that enables a filter characteristic to be adjusted flexibly, and a radio communication apparatus equipped with this sampling filter. A sampling filter apparatus () is equipped with four integration units (-through-) corresponding to the number of filter taps, and some of the integration units (-through-) include an integrator having an MEMS structure. By this means, a charge amount (accumulated charge amount) of a received signal integrated by an integrator can be adjusted by adjusting the capacity of an integrator having an MEMS structure. A received signal amount emitted from an integration unit can also be adjusted by adjustment of the integration amount of a received signal, enabling the filter characteristic of the sampling filter apparatus () to be adjusted flexibly.

Sampling filter and radio communication apparatus

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Kanagawa, Japan

Katsuaki Abe