Abstract: According to one embodiment, a wireless receiving apparatus includes a detector, a demodulator, a determination unit and a setting unit. The detector detects a wireless frame which has a received power level higher than a carrier detection threshold when the wireless frame is received. The determination unit determines a connection status in accordance with whether or not the demodulation is successful. The setting unit sets the carrier detection threshold at a first threshold if the connection status is an initial status where demodulation of a connection request frame is not successful, and which sets the carrier detection threshold at a second threshold if the connection status is other than the initial status, the second threshold being a variable value and larger than the first threshold.

Abstract: According to one embodiment, a transmitting device includes a transmitter configured to transmit a frame; a first carrier sensor configured to perform carrier sense in a wider bandwidth than a signal bandwidth to be used for a transmission of the frame by the transmitter; and an idle detector configured to determine whether the first carrier sensor succeeds in detecting an idle for a period that is equal to or more than a period for the transmitter to transmit the frame. The transmitter is configured to, when the idle detector succeeds in the idle detection, start the transmission of the frame after a lapse of a first period after the success of the idle detection.

Abstract: According to one embodiment, a wireless communication apparatus using a first wireless communication scheme includes a transmitter and controller. The controller which controls IFSs so as to set, one of the first IFS and the second IFS as an IFS used during the first period. the controller sets the second IFS to at least a second period when a channel is idle during a period corresponding to a fourth IFS after one of the IFS is switched from the first IFS to the second IFS and when the channel becomes busy after the period corresponding to the fourth IFS is elapsed, the fourth IFS being an IFS before the transmission of a beacon signal, the second period being one of a plurality of first periods and being a period which includes timing for an estimated cycle of the beacon signal.

Abstract: According to one embodiment, a wireless communication apparatus has a transmitter, a receiver, and a transmission timing instructor. The transmitter transmits a signal by using a first wireless communication scheme. The receiver receives a signal transmitted by using the first wireless communication scheme. The receiver detects a signal of which a frequency band includes at least a part of a frequency band used in the first wireless communication scheme, which is other than a signal transmitted by using the first wireless communication scheme. The transmission timing instructor instructs the transmitter to transmit a signal by using the first wireless communication scheme if the receiver does not receive a signal over a predetermined time from a detection of a signal other than a signal transmitted by using the first wireless communication scheme.

Abstract: According to one embodiment, a wireless communication apparatus includes a transceiver, an estimator and a controller. The transceiver transmits and receives a frame in a frequency band which is used by a first system executing communication in a first communication range determined by a first transmission power and a first antenna gain. The estimator determines whether an amount of interference in the frequency band from a second system is no less than a threshold, the second system executing communication in a second communication range which is larger than the first communication range and which is determined by a second transmission power and a second antenna gain. The controller increases a transmission power when the amount of interference is no less than the threshold.

Abstract: According to an embodiment, a communication apparatus controls controllable nodes. The apparatus includes an acquisition unit and a generation unit. The acquisition unit acquires at least one of a first evaluation value indicating an occurrence frequency of a control request to a target controllable node and a second evaluation value indicating an occurrence frequency of communication error at the target controllable node. The generation unit generates identification information to be assigned to control the target controllable node in a manner such that a bit length of the identification information becomes shorter as at least one of the first evaluation value and the second evaluation value increases.

Abstract: The transmitter includes a first bit generator, a modulator, a second bit generator and a bit converter. The first bit generator generates bits to be transmitted based on the first wireless scheme. The modulator for the first wireless scheme performs at least amplitude modulation of a multiple level on the bits generated by the first bit generator. The second bit generator generates a bit to be transmitted based on the second wireless scheme. The bit converter converts the bit generated by the second bit generator and inputs converted bits to the modulator wherein the bit converter converts the bit generated by the second bit generator so that a signal showing High in the second wireless scheme is modulated to amplitude of a high level in the multiple level in the modulator.

Abstract: According to one embodiment, a transmitting apparatus includes a generation unit, a division unit, an imparting unit and a transmitting unit. The generation unit generates first control information in accordance with a first information format. The division unit divides the first control information into control information pieces in accordance with information format divisions into which the first information format is divided and which include respective pointer regions, each of the information format divisions having a same data length as a second information format. The imparting unit imparts, to the pointer region of each of the information format divisions, a pointer indicating a wireless communication resource used to transmit one of the control information pieces corresponding to one of the information format divisions other than the each control information format division. The transmitting unit transmits the control information pieces.

Abstract: According to one embodiment, a quadrature error compensating circuit for acquiring an in-phase component signal and a quadrature component signal, includes a first filter, a first multiplier, a first subtractor, a second filter, a correlation calculating circuit. The first multiplier multiplies the in-phase component signal by a control value. The correlation calculating circuit calculates a cross-correlation value between an output of the first filter and an output of the second filter, and uses the cross-correlation value as the control value.

Abstract: A wireless communication device has a first wireless communication unit capable of performing wireless communication within a first communication distance, a second wireless communication unit capable of performing wireless communication within a second communication distance greater than the first communication distance, and a controller configured to assign at least a part of the wireless communication performed by the second wireless communication unit to the first wireless communication unit instead of the second wireless communication unit, based on a communication history of the second wireless communication unit stored after the wireless communication using the first wireless communication unit becomes available.

Abstract: According to one embodiment, a mobile wireless terminal, which makes a wireless communication with a base station accommodated in a network, includes a receiver, a communication module, and a controller. The receiver is configured to receive and frequency-convert a wireless signal transmitted from the base station, and to detect a beacon signal transmitted from the base station based on a reception signal obtained by the frequency conversion. The communication module is configured to receive a wireless signal transmitted from the base station, to acquire identification information of the base station by decoding a reception signal obtained from the wireless signal, and to communicate with the base station. The controller is configured to activate the communication module in accordance with a reception result of the beacon signal by the receiver, and to control the communication module to acquire identification information from the base station.

Abstract: According to one embodiment, a receiving apparatus includes a variable gain amplifier, comparator, and signal processor. The comparator compares a signal level of the second signal with a first threshold to generate a third signal, a signal level of the third signal being set to a high signal if the signal level of the second signal is greater than the first threshold. The signal processor determines presence of a signal if a rate of high signals in third signals for a period is greater than a second threshold. The second threshold is set to a first value when the control of the gain is performed and set to a second value when the demodulation processing is performed. The first value is greater than the second value.

Abstract: According to one embodiment, a communication device, which performs communication using a first communication method and a second communication method, converts information to be transmitted into information for forming a pulse that is formed depending on the presence and absence of transmission of a radio wave, according to the first communication method. The communication device decides a suppression time, during which communication with a communication device other than a communication partner is suppressed, on the basis of a result of the conversion. The communication device generates an output signal including the transmission suppression signal, in which the suppression time is set for each first element in the pulse, according to the second communication method, the first element transmitting a radio wave. The communication device transmits a radio wave according to the output signal to the communication partner at timing to transmit a radio wave in the pulse.

Abstract: According to one embodiment, a radio apparatus configured to communicate with a second radio apparatus after receiving plural first signals transmitted from the second radio apparatus in a constant cycle, the radio apparatus includes: a communication circuit configured to communicate with the second radio apparatus; a wave detection circuit configured to generate a wave detection signal by envelope-detecting the plural first signals; a bandpass filter having an IIR filter, configured to generate a detection signal form the wave detection signal, the detection signal having amplitude is increased at a frequency corresponding to the constant cycle; and a control unit configured to cause supply of power to the communication circuit if the amplitude is larger than a first threshold value.

Abstract: According to one embodiment, a quadrature error compensating circuit for acquiring an in-phase component signal and a quadrature component signal, includes a first filter, a first multiplier, a first subtractor, a second filter, a correlation calculating circuit. The first multiplier multiplies the in-phase component signal by a control value. The correlation calculating circuit calculates a cross-correlation value between an output of the first filter and an output of the second filter, and uses the cross-correlation value as the control value.

Abstract: A radio apparatus capable of correcting a direct current offset with high accuracy in a short time is provided. A radio apparatus according to an embodiment includes a first amplifier amplifying a signal inputted to an input terminal with amplification gain determined by a variable resistor to generate a first amplified signal, and a second amplifier amplifying the first amplified signal to generate a second amplified signal. Further, the radio apparatus includes a first correcting unit correcting a direct current offset of the first amplifier, and a second correcting unit correcting a direct current offset of the second amplifier.

Abstract: According to one embodiment, a transmitting device includes a transmitter configured to transmit a frame; a first carrier sensor configured to perform carrier sense in a wider bandwidth than a signal bandwidth to be used for a transmission of the frame by the transmitter; and an idle detector configured to determine whether the first carrier sensor succeeds in detecting an idle for a period that is equal to or more than a period for the transmitter to transmit the frame. The transmitter is configured to, when the idle detector succeeds in the idle detection, start the transmission of the frame after a lapse of a first period after the success of the idle detection.

Abstract: An electronic system includes: an AC-DC converter to convert an AC voltage into a DC voltage and to supply the DC voltage to a secondary battery; a first detector to detect a remaining amount of the secondary battery; a transmitter to transmit a signal corresponding to the remaining amount of the secondary battery; a receiver to receive the signal transmitted by the transmitter; and a controller to control the AC-DC converter using the signal received by the receiver.

Abstract: A transmitter includes a power measurement unit, a carrier sense unit, and a transmission unit. A first frequency band is allocated to a TDMA system. The power measurement unit measures a receiving power over a part of a first frequency band and a second frequency band. The carrier sense unit continues to check for a certain duration whether the receiving power is smaller than a threshold. The transmission unit generates a transmission signal including a dummy signal and a data signal when the receiving power has been smaller than the threshold for the certain duration. Moreover, the transmission unit transmits the transmission signal using the second frequency band.

Abstract: According to an embodiment, a communication apparatus controls controllable nodes. The apparatus includes an acquisition unit and a generation unit. The acquisition unit acquires at least one of a first evaluation value indicating an occurrence frequency of a control request to a target controllable node and a second evaluation value indicating an occurrence frequency of communication error at the target controllable node. The generation unit generates identification information to be assigned to control the target controllable node in a manner such that a bit length of the identification information becomes shorter as at least one of the first evaluation value and the second evaluation value increases.