Abstract: Provided is a stepping motor abnormality detecting device capable of detecting an abnormality of a stepping motor. Stepping motor abnormality detecting device (100) includes power supply (1), stepping motor (4), stepping motor driver (3), determiner (5), and controller (6). Controller (6) causes stepping motor driver (3) to operate stepping motor (4), current level detector (2) to acquire a current level while stepping motor (4) is driven, and determiner (5) to detect the abnormality of stepping motor (4) by comparing the current level acquired with a predetermined threshold.

Abstract: 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.

Abstract: 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 section 11 outputs a PM test signal and an AM test signal. The AM test signal is inputted to a multiplier 16 via a delay adjustment section 12 and a regulator 14. The PM test signal is inputted to the multiplier 16 via the delay adjustment section 12. A power measurement section 17 measures an average power of a multiplication signal which is outputted from the multiplier 16 and outputs a measured value to a control section 18. The control section 18 determines 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 12.

Abstract: 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.

Abstract: 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 section 11 outputs a PM test signal and an AM test signal. The AM test signal is inputted to a multiplier 16 via a delay adjustment section 12 and a regulator 14. The PM test signal is inputted to the multiplier 16 via the delay adjustment section 12. A power measurement section 17 measures an average power of a multiplication signal which is outputted from the multiplier 16 and outputs a measured value to a control section 18. The control section 18 determines 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 12.

Abstract: Provided is a transmission circuit which can adjust a difference between signal delay amounts in the amplitude path and the phase path with a low power consumption. An amplitude modulation section 15 amplitude-modulates a phase modulation signal outputted from a phase modulation section 14 with a voltage control signal provided by a regulator 13 to generate a transmission signal for an output of an antenna. Similarly, a feedback signal generation section 16 amplitude-modulates the phase modulation signal with the voltage control signal to generate a feedback signal FB. The signal FB is fed back to a delay adjustment section 12 and 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 16 is attained by a power amplifier having the same configuration as the amplitude modulation section 15 and a smaller circuit scale.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 {?, ?, ??, ??}, {?, ??, ??, ?}, {??, ?, ?, ??}, and {??, ??, ?, ?} where ? 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.

Abstract: An object is to generate a pilot signal for estimating transmission characteristic of a transmission channel which is suitable for the 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, and the transmission characteristic of the transmission channel is estimated and compensated by using the phase reference pilot signal and the amplitude reference pilot signal at the reception end. Thus, it is possible to simplify frame generation process performed at the transmission end, and reduce transmission power for the phase reference pilot signal.

Abstract: An object is to reduce inter-carrier interference caused by frequency fluctuations, amplitude fluctuations, phase fluctuations, or the like without reducing a transmission efficiency. On a receiving end, a canceling filter section (223) is provided, alleviating the inter-carrier interference caused by the frequency fluctuations, the amplitude fluctuations, the phase fluctuations, or the like through filtering processing. On a transmitting end, a precoding section (211) is provided, facilitating determination of demodulation data in a vector demodulation section (224) on the receiving end through precoding processing. Or on the receiving end, a trellis decoding section (225) is provided, decoding the demodulation data through trellis decoding processing.

Abstract: 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.

Abstract: 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.

Abstract: 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 {?, ?, ??, ??}, {?, ??, ??, ?}, {??, ?, ?, ??}, and {??, ??, ?, ?} where ? 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.

Abstract: In a mobile communication system in which the same frequency channel f1 is used to perform communication of the same data between a moving mobile station 2 and a plurality of base stations 1a to 1d while sequentially establishing synchronization therebetween, subcarriers assigned to the base stations 1a to 1d are set so as to satisfy the following conditions. 1. The same frequency channel f1 is used for all the base stations. 2. Subcarriers do not overlap between adjacent base stations. 3. Adjacent subcarriers are not used in each subcarrier set. 4. All subcarriers within the frequency channel f1 (subcarriers having closest intervals which can hold an orthogonal relationship) are used.

Abstract: A first frequency synchronization unit (103) corresponds to the frequency synchronization apparatus of the present invention. A higher apparatus that is, for example, a wireless receiver supplies a reception signal to the first frequency synchronization unit (103) via an A/D converter (101) and an orthogonal detector (102). A synchronization symbol that includes a predetermined waveform at least twice is incorporated into the reception signal. A correlation estimator (104) generates a reference signal expressing the same waveform as the synchronization symbol, and successively finds correlation vectors between the reception signal and the reference signal. A first signal error detector (106) finds a frequency error based on an average phase difference of predetermined correlation vectors, and finds an absolute phase error based on transition of absolute phase of predetermined correlation vectors.