Abstract: According to one embodiment, a timing determining device used in a mobile terminal, includes processing circuitry. The processing circuitry performs a detecting process of whether the mobile terminal is positioned at a reference point being a point at which a predetermined condition is satisfied for the mobile terminal. The processing circuitry employs feasibility data representing relationship between an adequacy of a communication environment and elapsed time from a start time point at which the mobile terminal is positioned at the reference point, estimates elapsed time until the adequacy satisfies a communication condition since the mobile terminal is positioned at the reference point and determines a timing of evaluating the communication environment according to an estimated elapsed time. The processing circuitry determines whether to permit the mobile terminal to perform communication on basis of measurement of the communication environment at the timing determined.

Abstract: A receiving apparatus includes a channel estimating unit that performs channel estimation by using a reception signal and obtains a channel estimation value, a demodulation processing unit that performs demodulation processing by using the channel estimation value and the reception signal, a weight calculating unit that calculates weight for decoding for each of channels by using the channel estimation value, and a decoding unit that performs decoding processing by using the weight and a result of the demodulation processing.

Abstract: Differential decoding processing applied to multilevel modulation is accomplished with the circuit scale kept small by including; an MSB coordinate rotating part for performing coordinate rotation based on information of the first two most significant bits of a signal received via a synchronous detection part; an MSB symbol likelihood generating part for generating likelihood with respect to the first two most significant bits after differential decoding, with the use of two sets of bit strings at different points in time for which coordinate rotation has been performed; an LSB symbol likelihood generating part for generating likelihood with respect to less significant bits; and a soft decision error correction decoding part for generating a decoded signal with the use of the likelihood of the first two most significant bits and the likelihood of the less significant bits.

Abstract: According to an embodiment, a communication device includes a receiving unit, an obtaining unit, and a transfer unit. The receiving unit receives acquisition information, which is sent from a general-purpose processor to a network and which represents information for obtaining data present on the network. Based on the received acquisition information, the obtaining unit obtains the data on behalf o the general-purpose processor. When processing unit data representing the data to be used in units of processing by the general-purpose processor is obtained, the transfer unit transfers the obtained processing unit data to the general-purpose processor.

Abstract: An optical modulator includes: a modulator including an optical waveguide provided in a semiconductor substrate having an electro-optical effect and an electrode to apply an electric field depending on a bias voltage and a modulation signal to the optical waveguide; a driver circuit to generate a modulation signal in accordance with an input signal; a superimposer to superimpose a reference signal on the bias voltage, the reference signal having lower frequency than the modulation signal; and a controller to control a bias voltage in a direction orthogonal to a modulation direction of the modulator based on the frequency component of the reference signal extracted from a modulated optical signal generated by the modulator.

Abstract: A communication system using hierarchical modulation and capable of flexibly adjusting line quality includes a transmission apparatus that hierarchically modulates and transmits signal sequences, a reception apparatus that hierarchically demodulates a received signal, and a hierarchization-parameter setting unit that sets hierarchization parameters. The transmission apparatus includes a hierarchical modulation unit that superimposes signals from layers while maintaining gray codes. The reception apparatus includes a hierarchical demodulation unit that demodulates and separates hierarchically modulated signals and detects signals from layers. The hierarchization-parameter setting unit sets a hierarchization ratio which is a signal power ratio used for superimposing a higher layer and a lower layer, a mapping pattern capable of selecting two patterns, and a mapping pattern mixing ratio indicating a ratio with which two mapping patterns are mixed.

Abstract: Differential decoding processing applied to multilevel modulation is accomplished with the circuit scale kept small by including; an MSB coordinate rotating part for performing coordinate rotation based on information of the first two most significant bits of a signal received via a synchronous detection part; an MSB symbol likelihood generating part for generating likelihood with respect to the first two most significant bits after differential decoding, with the use of two sets of bit strings at different points in time for which coordinate rotation has been performed; an LSB symbol likelihood generating part for generating likelihood with respect to less significant bits; and a soft decision error correction decoding part for generating a decoded signal with the use of the likelihood of the first two most significant bits and the likelihood of the less significant bits.

Abstract: According to one embodiment, a communication apparatus includes a communication unit that performs radio communication with a corresponding apparatus. The communication apparatus includes a measuring unit that measures a communication state of the radio communication performed by the communicating unit. The communication apparatus includes a determining unit that determines appropriateness of data communication with the corresponding apparatus performed by the communicating unit, based on a plurality of parameters with respect to the communication state obtained by measurement made by the measuring unit.

Abstract: A receiving apparatus includes a channel estimating unit that performs channel estimation by using a reception signal and obtains a channel estimation value, a demodulation processing unit that performs demodulation processing by using the channel estimation value and the reception signal, a weight calculating unit that calculates weight for decoding for each of channels by using the channel estimation value, and a decoding unit that performs decoding processing by using the weight and a result of the demodulation processing.

Abstract: There is provided a processing apparatus, including: first and second processors; a first storage which data read or data write is done by one or more fixed-size blocks, data in each block having a sequential address; and a controller to control operation of at least one of the first and the second processors. One of the processors writes, to the first storage, first to N-th data pieces so that an ending address of an X-th data piece and a starting address of an X+1-th data piece are sequential. The controller sets the other processor in a low power consumption mode during at least a part of a period in which the one processor performs writing to the storage, and after that, the controller sets the other processor in a normal or active operating mode in which the other processor is capable of reading the data pieces from the first storage.

Abstract: An optical modulator includes: a modulator including an optical waveguide provided in a semiconductor substrate having an electro-optical effect and an electrode to apply an electric field depending on a bias voltage and a modulation signal to the optical waveguide; a driver circuit to generate a modulation signal in accordance with an input signal; a superimposer to superimpose a reference signal on the bias voltage, the reference signal having lower frequency than the modulation signal; and a controller to control a bias voltage in a direction orthogonal to a modulation direction of the modulator based on the frequency component of the reference signal extracted from a modulated optical signal generated by the modulator.

Abstract: An optical modulator includes: a modulator including an optical waveguide provided in a semiconductor substrate having an electro-optical effect and an electrode to apply an electric field depending on a bias voltage and a modulation signal to the optical waveguide; a driver circuit to generate a modulation signal in accordance with an input signal; a superimposer to superimpose a reference signal on the bias voltage, the reference signal having lower frequency than the modulation signal; and a controller to control a bias voltage in a direction orthogonal to a modulation direction of the modulator based on the frequency component of the reference signal extracted from a modulated optical signal generated by the modulator.

Abstract: A soft decision value generation circuit capable of reducing amount of calculation and hardware scale for generating a soft decision value. The soft decision value generation circuit includes: a phase rotation unit rotating phases of received symbols after coherent detection; addition units calculating, by using the phase-rotated received symbols, absolute values of soft decision values for soft decision value candidates restricted in advance; minimum value selection units selecting minimum values out of the absolute values of the soft decision values; sign reflection units reflecting, based on the phases of the received symbols after the phase rotation, sign information to the minimum values; and soft decision value correction units multiplying outputs of the sign reflection units by a coefficient depending on a noise variance value and an amplitude value of a modulation symbol.

Abstract: An optical receiver includes: an optical receiving device configured to generate an analog received signal that represents a received modulated optical signal; an A/D converter configured to generate a digital received signal from the analog received signal; an E/O circuit configured to generate an optical digital signal from the digital received signal; an O/E circuit configured to generate an electric digital signal from the optical digital signal; and a digital signal processor configured to recover a data signal from the electric digital signal.

Abstract: An optical modulator includes: a modulator including an optical waveguide provided in a semiconductor substrate having an electro-optical effect and an electrode to apply an electric field depending on a bias voltage and a modulation signal to the optical waveguide; a driver circuit to generate a modulation signal in accordance with an input signal; a superimposer to superimpose a reference signal on the bias voltage, the reference signal having lower frequency than the modulation signal; and a controller to control a bias voltage in a direction orthogonal to a modulation direction of the modulator based on the frequency component of the reference signal extracted from a modulated optical signal generated by the modulator.

Abstract: A wireless communication system includes a transmission device including plural transmission antennas and a receiving device including plural reception antennas. The transmission device includes a branching unit that branches a signal into plural transmission signals respectively passing plural signal lines each corresponding to each of the transmission antennas and delay units provided on at least one of the signal lines to apply a delay to the transmission signal. When a transmission signal branched by the branching unit is applied with a delay by the delay units, the transmission device sets the transmission signal on which the delay is applied as the transmission signal, and transmits the transmission signals to the receiving device via the transmission antennas.

Abstract: An optical transmitter includes: a selection circuit; a signal processing circuit; an optical modulator; and a control circuit. The selection circuit selects signal components on the sides of the maximum and minimum values in a multivalued electrical signal for modulation of a transmitting signal. The signal processing circuit generates a multivalued electrical signal into which the transmitting signal is converted by a combination of a superimposed signal that a low-frequency wave is superimposed on the signal components and a signal having a plurality of intermediate amplitude values on which the low-frequency wave is not superimposed. The optical modulator modulates a carrier light on the basis of the multivalued electrical signal. The control circuit controls the reference amplitude value or amplitude of the multivalued electrical signal on the basis of the low-frequency components contained in a modulated optical signal.

Abstract: According to an embodiment, a communication device includes a first processor and a second processor. The first processor is switchable to a sleep state having low power consumption. The second processor performs operations related to information acquisition via a network. The second processor includes a networking unit, an information obtaining unit, and a start-up control unit. Based on first information which indicates a connection destination of the network as specified in the first processor, the networking unit performs communication with the connection destination and notify a permission of switching the first processor to the sleep state. The information obtaining unit obtains second information which is associated to the first information. The start-up control unit switches the first processor back to an operating state from the sleep state when the information obtaining unit finishes obtaining the second information associated to the first information specified by the first processor.

Abstract: In general, according to one embodiment, an information processing apparatus includes an issuer and a communicator. The issuer issues an offload instruction corresponding to a first process executed in company with a first identifier capable of uniquely specifying a resource of a first arithmetic operation device. The communicator transmits the offload instruction to a second arithmetic operation device and receives a result of execution of the offload instruction from the second arithmetic operation device. In the second arithmetic operation device, the first identifier contained in the offload instruction is converted into a second identifier capable of uniquely specifying a resource of the second arithmetic operation device, and processing specified by the offload instruction is executed.

Abstract: According to some embodiments, there is provided a communication device including: a processing unit and a notifying unit. The processing unit receives an acquisition request of first information from a requester and determines based on a predetermined condition whether or not the first information needs to be acquired from an acquisition destination of the first information. The notifying unit notifies a first response to the requester when the processing unit determines that the first information needs to be acquired, the first response containing an instruction of transitioning to a low power consumption status.