Abstract: According to one embodiment, a failure detection apparatus includes a communicator, a selector, an execution unit, and a determiner. The communicator communicates with a wireless terminal mounted on a moving object via at least one of first bridge devices located at predetermined positions. The selector selects second bridge devices from the first bridge devices. The execution unit executes test connections to the wireless terminal using the second bridge devices. The determiner determines that the wireless terminal is inoperative if the test connection via any of the second bridge devices has failed.

Abstract: A radio transmitting apparatus includes a storage unit configured to store a plurality of weight sequence sets, which are each assigned to a plurality of transmission blocks sectioned by time axes and frequency axes, by associating the plurality of weight sequence sets with the plurality of transmission blocks, a first selecting unit configured to select one transmission block from the plurality of transmission blocks, a second selecting unit configured to select one weight sequence from one weight sequence set assigned to the one transmission block signal, a converting unit configured to convert a data signal by using the one weight sequence to generate a converted signal, and a transmitting unit configured to transmit the converted signal by using the one transmission block.

Abstract: According to one embodiment, a transmitting apparatus includes a transmitting unit and a selecting unit. The transmitting unit transmits first control information using one of first communication resources. The first communication resources are included in a first transmission band and have respective independent numbers. The transmitting unit transmits second control information using one of second communication resources. The second communication resources are included in a second transmission band and have respective independent numbers. The selecting unit restricts the second communication resources to restricted second communication resources in accordance with a number assigned to one of the first communication resources used to transmit the first control information, and to select one second communication resource from the restricted second communication resources. The transmitting unit transmits the second control information using the selected second communication resource.

Abstract: A radio communication method includes generating a first transmit RF signal and a second transmit RF signal from a data signal to be transmitted. Each of the first and second transmit RF signals have a power spectrum in symmetric shape in the frequency domain. The first transmit RF signal and the second transmit RF signal are transmitted at a different time. The first transmit RF signal and the second transmit RF signal are received to generate a first received RF signal and a second received RF signal. The data signal from the first received RF signal and the second received RF signal are reproduced.

Abstract: A transmitter includes first generator to generate pilot source signal by modulating pilot sequence, second generator to generate data source signal with time length longer than that of pilot source signal by modulating data sequence, first cyclic shifter to perform cyclic shift of first shift amount to pilot source signal to generate first pilot signal, second cyclic shifter to performs cyclic shift of second shift amount to data source signal to generate first data signal, third cyclic shifter to perform cyclic shift of third shift amount to pilot source signal to generate second pilot signal, fourth cyclic shifter to perform cyclic shift of fourth shift amount to data source signal to generate second data signal, first transmit antenna to transmit first pilot signal and first data signal, and second transmit antenna to transmit second pilot signal and second data signal.

Abstract: In a method for communication, first and second signals for timing synchronization are generated. Frequencies of the first and second signals are converted to other frequencies to obtain a first and second RF signals, which have a specific frequency gap therebetween. The first and second RF signals are combined to obtain a transmission signal, and the transmission signal is transmitted. When the transmission signal is received as a received signal, the frequency of the received signal is shifted by the specific frequency gap to obtain a converted signal. A complex conjugation of the converted signal calculated to obtain a complex conjugation signal. The received signal and the complex conjugation signal are multiplied to obtain a multiplication signal to calculate cross-correlation between a product of the first and second signals and the multiplication signal. A peak of the cross-correlation is detected to set a base time for timing synchronization.

Abstract: There is provided a radio power transmitting apparatus including: a power transmitting coil, a band signal generating unit, a reflected signal measuring unit, an oscillator and a communication control unit. The coil is supplied with a signal and transmits the signal to a power receiving coil on a radio power receiving apparatus through magnetic coupling. The generating unit generates a band signal having an allowable transmission band and supplies the band signal to the power transmitting coil. The reflected signal measuring unit measures a reflected signal of the band signal from the power transmitting coil. The oscillator generates a carrier signal having a controllable oscillating frequency. The control unit determines a transmission frequency based on a frequency characteristic of the reflected signal and performs control so that a transmission signal generated by modulating the carrier signal of the transmission frequency is supplied to the power transmitting coil.

Abstract: Disclosed is a communication system, having: a transmitter including: a first frequency converter converting a frequency of a provided signal to a first frequency band to generate a first signal and converting the frequency of the provided signal to a second frequency band to generate a second signal, the second frequency band having a given frequency difference against the first frequency band; and a combiner combining the first signal and the second signal to output a transmission signal, and a receiver including: a second frequency converter converting the transmission signal to a frequency-shifting signal shifted by the given frequency difference; a first multiplier multiplying the transmission signal and the frequency-shifting signal together to output a multiplied signal; a filter extracting a baseband signal from the multiplied signal; and a detector detecting significant information from the baseband signal.

Abstract: A transmitter includes first generator to generate pilot source signal by modulating pilot sequence, second generator to generate data source signal with time length longer than that of pilot source signal by modulating data sequence, first cyclic shifter to perform cyclic shift of first shift amount to pilot source signal to generate first pilot signal, second cyclic shifter to performs cyclic shift of second shift amount to data source signal to generate first data signal, third cyclic shifter to perform cyclic shift of third shift amount to pilot source signal to generate second pilot signal, fourth cyclic shifter to perform cyclic shift of fourth shift amount to data source signal to generate second data signal, first transmit antenna to transmit first pilot signal and first data signal, and second transmit antenna to transmit second pilot signal and second data signal.

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 transmitting apparatus includes a transmitting unit and a selecting unit. The transmitting unit transmits first control information using one of first communication resources. The first communication resources are included in a first transmission band and have respective independent numbers. The transmitting unit transmits second control information using one of second communication resources. The second communication resources are included in a second transmission band and have respective independent numbers. The selecting unit restricts the second communication resources to restricted second communication resources in accordance with a number assigned to one of the first communication resources used to transmit the first control information, and to select one second communication resource from the restricted second communication resources. The transmitting unit transmits the second control information using the selected second communication resource.

Abstract: A transmitter includes first generator to generate pilot source signal by modulating pilot sequence, second generator to generate data source signal with time length longer than that of pilot source signal by modulating data sequence, first cyclic shifter to perform cyclic shift of first shift amount to pilot source signal to generate first pilot signal, second cyclic shifter to performs cyclic shift of second shift amount to data source signal to generate first data signal, third cyclic shifter to perform cyclic shift of third shift amount to pilot source signal to generate second pilot signal, fourth cyclic shifter to perform cyclic shift of fourth shift amount to data source signal to generate second data signal, first transmit antenna to transmit first pilot signal and first data signal, and second transmit antenna to transmit second pilot signal and second data signal.

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.

Abstract: Broadcast data is divided into a plurality of broadcast channels. Any of the plurality of broadcast channels is placed on a predetermined subcarrier in each of a plurality of main bands such that the placed broadcast channels differ from each other in a same frame and are consecutive in a predetermined order in a frame direction. The subcarriers are converted into a transmit RF signal and the transmit RF signal is transmitted.

Abstract: According to one embodiment, a radio relay apparatus includes a reception unit, a cancellation unit, a weight calculation unit, and a weight multiplication unit. The reception unit generates M first baseband signals based on M first RF signals supplied by M reception antennas. The cancellation unit subtracts M replicated signals replicating loop interference signals in the M reception antennas, from the respective M first baseband signals, to obtain M second baseband signals. The weight calculation unit calculates M×M weights corresponding to M×M loop interference channels. The weight multiplication unit multiplies the M second baseband signals by the M weights corresponding to the respective M reception antennas and then combines resultant signals together to obtain M replicated signals to be supplied to the cancellation unit.

Abstract: A cognitive radio system includes: a state detecting device that scans a frequency band allocated to another radio system than the cognitive radio system to detect a first use-state of the frequency band; a first server including a first gathering unit that receives first information relating to the first use-state and a second gathering unit; a second server that stores a second use-state of the frequency band allocated to the other radio system, the second server configured to provide second information relating to the second use-state to the second gathering unit; and a notifying unit that notifies a terminal device in the cognitive radio system of information of an available channel based on the first information and the second information.

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.

Abstract: There is provided with a radio communication system in which a base station using a multicarrier transmission scheme as a transmission scheme and a terminal apparatus are wirelessly connected, wherein the base station includes: a data generator configured to generate first pilot signals for the terminal apparatus to measure channel quality, second pilot signals for the terminal apparatus to estimate a channel and data signals to be transmitted to the terminal apparatus; a transmission power controller configured to control transmission power of the second pilot signals and the data signals by adjusting amplitude of the second pilot signals and the data signals respectively; and a transmitter configured to generate subcarrier data by mapping the first pilot signals, the second pilot signals power-controlled by the transmission power controller and the data signals power-controlled by the transmission power controller to a plurality of subcarriers and transmit the subcarrier data generated.

Abstract: In a method for communication, first and second signals for timing synchronization are generated. Frequencies of the first and second signals are converted to other frequencies to obtain a first and second RF signals, which have a specific frequency gap therebetween. The first and second RF signals are combined to obtain a transmission signal, and the transmission signal is transmitted. When the transmission signal is received as a received signal, the frequency of the received signal is shifted by the specific frequency gap to obtain a converted signal. A complex conjugation of the converted signal calculated to obtain a complex conjugation signal. The received signal and the complex conjugation signal are multiplied to obtain a multiplication signal to calculate cross-correlation between a product of the first and second signals and the multiplication signal. A peak of the cross-correlation is detected to set a base time for timing synchronization.