Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Yukihiro Omoto

Tomohiro Kimura

Kenichi Mori

Yoshio Urabe

Takashi Watanabe

Kaoru Ishida

Naganori Shirakata

Shigeru Morimoto

Hiroshi Komori

Yasuo Harada

Takayuki Matsumoto

Ryo Kitamura

Shota Teramoto

Yoshio Horiike

Takanori Kamimura

Koichi Toyota

Jumpei Niwa

Akiyoshi Kawauchi

Kenzo Tomitani

Provided is a stepping motor abnormality detecting device capable of detecting an abnormality of a stepping motor. Stepping motor abnormality detecting device () includes power supply (), stepping motor (), stepping motor driver (), determiner (), and controller (). Controller () causes stepping motor driver () to operate stepping motor (), current level detector () to acquire a current level while stepping motor () is driven, and determiner () to detect the abnormality of stepping motor () by comparing the current level acquired with a predetermined threshold.

Stepping motor abnormality detecting device

Provided is a transmitter apparatus including: a signal conversion section for, in polar modulation, converting input data into an amplitude-component signal and a phase-component signal, and in quadrature modulation, converting input data into an in-phase component signal and a quadrature component signal; a carrier wave generation section for outputting a carrier wave; a mixer section for, in quadrature modulation, generating a quadrature modulation signal; a regulator for, in polar modulation, outputting a supply voltage control signal; and a power amplifier for, in polar modulation, amplifying the supply voltage control signal and superimposing the resultant signal onto the carrier wave, thereby generating a transmission signal, wherein in polar modulation, the carrier wave generation section outputs the carrier wave modulated with respect to phase component, and in quadrature modulation, the carrier wave generation section outputs the carrier wave that is yet to be modulated.

Transmitter apparatus

A transmission circuit adjust a difference between signal delay amounts in an amplitude path and a phase path with a low power consumption. An amplitude modulation section amplitude-modulates a phase modulation signal outputted from a phase modulation section with a voltage control signal provided by a regulator to generate a transmission signal for an output of an antenna. Similarly, a feedback signal generation section amplitude-modulates the phase modulation signal with a voltage control signal to generate a feedback signal. The signal is fed back to a delay adjustments sections used for calculating and adjusting the difference between the signal delay amounts in the amplitude path and the phase path. The feedback signal generation section is attained by a power amplifier having the same configuration as the amplitude modulation section and a smaller circuit scale.

Transmission circuit and communication apparatus using polar modulation method

Provided is a transmitter which is small in size and operates with high efficiency and compensates a delay error with high accuracy. A signal generation sectionoutputs a PM test signal and an AM test signal. The AM test signal is inputted to a multipliervia a delay adjustment sectionand a regulator. The PM test signal is inputted to the multipliervia the delay adjustment section. A power measurement sectionmeasures an average power of a multiplication signal which is outputted from the multiplierand outputs a measured value to a control section. The control sectiondetermines an amplitude delay time and a phase delay time on the basis of the inputted measured value and sets the determined delay times in the delay adjustment section

Transmitter and communication apparatus

Inter-carrier interference caused by frequency fluctuations, amplitude fluctuations, phase fluctuations, or the like is reduced without reducing a transmission efficiency. A receiving end has a canceling filter section that alleviates the inter-carrier interference caused by the frequency fluctuations, the amplitude fluctuations, the phase fluctuations, or the like through filtering processing. A transmitting end has a precoding section that facilitates determination of demodulation data in a vector demodulation section on the receiving end through precoding processing. Or, the receiving end has a trellis decoding section that decodes the demodulation data through trellis decoding processing.

Transmission apparatus and a reception apparatus in a multicarrier transmission system and a transmission method and a reception method using the multicarrier transmission system

In order is to generate a pilot signal for estimating a transmission characteristic of a transmission channel suitable for OFDM/OQAM multicarrier modulation, a phase reference pilot symbol of which a modulation amplitude is suppressed to zero, and an amplitude reference pilot signal obtained through modulation performed by using an amplitude known to a reception end are transmitted from a transmission end. Further, the transmission characteristic of the transmission channel is estimated and compensated using the phase reference pilot signal and the amplitude reference pilot signal at the reception end. Accordingly, it is possible to simplify a frame generation process performed at the transmission end, and reduce transmission power for the phase reference pilot signal.

Multicarrier modulation scheme as well as transmission apparatus and reception apparatus using the scheme

In a transmitter, at least one pilot carrier which is modulated with a signal sequence including a reference pilot signal sequence represented by any of amplitude modulation vectors {&#x3b1;, &#x3b1;, &#x2212;&#x3b1;, &#x2212;&#x3b1;}, {&#x3b1;, &#x2212;&#x3b1;, &#x2212;&#x3b1;, &#x3b1;}, {&#x2212;&#x3b1;, &#x3b1;, &#x3b1;, &#x2212;&#x3b1;}, and {&#x2212;&#x3b1;, &#x2212;&#x3b1;, &#x3b1;, &#x3b1;} where &#x3b1; represents a real number other than 0, is generated, and an OFDM/OQAM multicarrier modulation signal is transmitted. In a receiver, the OFDM/OQAM multicarrier modulation signal is demodulated, and transmission channel characteristics are estimated and corrected based on two successive demodulation vectors in a time direction which are obtained by demodulating the pilot carrier.

Multicarrier transmission method, multicarrier modulation signal transmission apparatus, multicarrier modulation signal reception apparatus, multicarrier modulation signal transmission method, and pilot signal generation method

A reception device according to the present invention receives a transmission frame including a synchronization symbol string, having a synchronization symbol repeated multiple times, inserted before a data symbol string. The synchronization symbol is obtained by synthesizing a plurality of sub band symbols which are mutually orthogonal and having different carrier frequencies. The carrier frequencies of the sub band symbols are located at an equal predetermined frequency interval. The synchronization symbol includes a repeated synchronization pattern. The reception device detects a rough carrier frequency error from a phase difference of a synchronization pattern correlation value to correct the frequency, and then detects a residual frequency error from an inter-symbol phase difference of each sub band to correct the frequency. The reception device detects a sampling clock frequency error from an inter-sub band phase difference to correct the frequency. Thus, the demodulation error of the data symbol is reduced.

Growing community of inventors

Osaka, Japan

Yukihiro Omoto