Abstract: According to one embodiment, a wireless communication device includes controlling circuitry configured to adjust a directivity of each of a plurality antennas based on a received power of a first frame for each of the plurality of antennas; and a transmitter configured to transmit a second frame for responding to the first frame after the directivity is adjusted.

Abstract: According to one embodiment, a wireless communication device includes: controlling circuitry configured to set at least one of: a first transmission prohibition period for a first network to which the wireless communication device belongs; or a second transmission prohibition period for a second network, and to determine, when a first frame addressed to another device is received in a case that the first transmission prohibition period is not set and the second transmission prohibition period is set, a state of a wireless medium based on comparing a reception level of the first frame with a threshold defined corresponding to one of the first network and the second network, to which a sender of the first frame belongs.

Abstract: According to one embodiment, a wireless communication device includes a first receiver; a second transmitter; a controller; and a pre-equalizer. The controller switches a reception frequency of the first receiver from a first frequency to a second frequency and a transmission frequency of the first transmitter from the second frequency to the first frequency, at a first timing. The pre-equalizer pre-equalizes a second signal, based on channel state information of a first signal received in the first receiver before the first timing. The first transmitter transmits the pre-equalized second signal, after the first timing.

Abstract: According to one embodiment, a wireless communication device includes: controlling circuitry configured to set at least one of: a first transmission prohibition period for a first network to which the wireless communication device belongs; or a second transmission prohibition period for a second network, and to determine, when a first frame addressed to another device is received in a case that the first transmission prohibition period is not set and the second transmission prohibition period is set, a state of a wireless medium based on comparing a reception level of the first frame with a threshold defined corresponding to one of the first network and the second network, to which a sender of the first frame belongs.

Abstract: A radio communication method stores a plurality MAC frames for each of a plurality of destinations. The method decides the longest transmission time of transmission times needed to transmit the plurality of MAC frames to each of the plurality of destinations within a fixed period. The method generates a plurality of physical frames for the plurality of destinations to transmit them at the same time by connecting the plurality of MAC frames and adding additional information to each connected MAC frame so as to be a frame length equivalent to a transmission time equal to the longest transmission time.

Abstract: A wireless communication device according to an aspect of the present invention includes a transmitter, a receiver, and a signal processor. The transmitter transmits a first signal. The receiver receives a second signal which includes information indicating a transmission channel characteristic at the time of transmission of the first signal. The signal processor acquires the transmission channel characteristic at the time of transmission of the first signal from the second signal, estimates a reception channel characteristic at the time of reception of the second signal from the second signal, and estimates a transmission channel characteristic at a time later than a time associated with the acquired transmission channel characteristic on the basis of the acquired transmission channel characteristic and the estimated reception channel characteristic. The transmitter transmits a third signal on the basis of the estimated transmission channel characteristic.

Abstract: A wireless communication device according to an aspect of the present invention includes a transmitter, a receiver, and a signal processor. The transmitter transmits a first OFDM signal. The receiver receives a second OFDM signal. The signal processor detects a first timing that is a symbol timing for the first OFDM signal, detects a second timing that is a symbol timing for the second OFDM signal, determines a setup value for a symbol length of a new first OFDM signal on the basis of the first timing and the second timing, and generates the new first OFDM signal, the symbol length of which is adjusted to the setup value.

Abstract: According to one embodiment, an antenna arrangement determination device includes a candidate value generator, a calculator and an antenna arrangement determiner. The candidate value generator generates candidate values of a distance between a plurality of antennas, at an interval according to an installation height of an arbitrary one of the antennas, the distance between the antennas being adjustable. The calculator calculates communication quality in a case of setting the distance between the antennas at the candidate values. The antenna arrangement determiner determines a setting value of the distance between the antennas from the candidate values based on the communication quality.

Abstract: According to one embodiment, a wireless communication device includes: a first transmitter configured to transmit a first frame to instruct transmission prohibition to a first wireless communication device, and to transmit a signal to a second wireless communication device during a period in which the transmission is prohibited; and a first receiver configured to receive power reception amount information corresponding to the signal after the signal is transmitted.

Abstract: According to one embodiment, a wireless communication apparatus is provided with first and second determination units. The first unit determines based on a first carrier sense threshold whether busy state or not and specifies a first time when busy state is determined with the first threshold, and determines based on a second carrier sense threshold smaller than the first threshold whether busy state or not and specifies a second time when busy state is determined. The second unit determines, if at least busy state is determined based on the second threshold and the second time precedes a reference time equal to or earlier than the first time, to perform processing for avoiding interference.

Abstract: According to one embodiment, a wireless communication device includes a receiver, a controller and a transmitter. The receiver receives a terminal identifier of a first terminal being a target for downlink frequency multiplexing transmission from another wireless communication device, and receives information identifying, of a plurality of frequency components, a first frequency component allocated to the first terminal. The controller selects, of a plurality second terminals belonging to the wireless communication device, a second terminal having a terminal identifier same as that of the first terminal and allocates the first frequency component to the selected second terminal.

Abstract: According to an embodiment, a communication device is provided in a movable body and is wirelessly communicable with a transceiver unit and another movable body. A receiver of the device receives transceiver unit information including traffic-light information that the transceiver unit has transmitted to a predetermined channel. An processing circuitry extracts the traffic-light information corresponding to a running direction of the movable body from the transceiver unit information. A transmitter transmits movable body information of the movable body to the predetermined channel. A processing circuitry controls a transmission timing of the movable body information such that a transmission control period becomes a preset first time. A processing circuitry changes the transmission control period to a second time longer than the first time, when the traffic-light information with respect to the running direction indicates a stopping command, and a speed of the movable body is a preset speed or less.

Abstract: A wireless communication terminal including a transmitter which transmits, to an external device, a frame including n frame sets each including a subheader field, a frame check sequence field, and a frame body field including data, where n is an integer of two or more. The subheader field includes a sequence number field which notifies a sequence number; a more fragment field which notifies whether or not the data is a last fragment; and a frame body length field which notifies a length of the frame body field. A receiver receives, from the external device, a response frame notifying a successively and successfully received maximum sequence number which indicates a highest sequence number among sequence numbers indicated in sequence number fields of frame sets which have been successively and successfully received by the external device among the n frame sets included in the transmitted frame.

Abstract: A wireless communication apparatus supports at least a second wireless communication scheme between a first wireless communication scheme and the second wireless communication scheme. The first wireless communication scheme requires that a wireless medium is determined to be busy when a reception level is equal to or greater than a minimum reception sensitivity level of a physical scheme. The apparatus includes first and second processing units. The first processing unit is configured to set a value lower than a maximum transmission power of the first wireless communication scheme, for a maximum transmission power of the second wireless communication scheme and set a value greater than the minimum reception sensitivity level of the physical scheme, for a carrier sense level, when the second wireless communication scheme is used. The second processing unit is configured to carry out carrier sense using the carrier sense level.

Abstract: A radio communication method stores a plurality MAC frames for each of a plurality of destinations. The method decides the longest transmission time of transmission times needed to transmit the plurality of MAC frames to each of the plurality of destinations within a fixed period. The method generates a plurality of physical frames for the plurality of destinations to transmit them at the same time by connecting the plurality of MAC frames and adding additional information to each connected MAC frame so as to be a frame length equivalent to a transmission time equal to the longest transmission time.

Abstract: According to an embodiment, a communication device is provided in a movable body and is wirelessly communicable with a transceiver unit and another movable body. The communication device includes a transmitter, a receiver, a synchronization unit, a registration unit, and a stop control unit. The transmitter transmits movable body information on the movable body to a predetermined channel. The receiver receives transceiver unit information that the transceiver unit has transmitted to the predetermined channel. The synchronization unit performs synchronization of reception timing when the transceiver unit information can be received. The registration unit registers a communication area of the transceiver unit calculated based on a position where the other movable body receives the transceiver unit information in storage.

Abstract: A wireless communication apparatus supports at least a second wireless communication scheme between a first wireless communication scheme and the second wireless communication scheme. The first wireless communication scheme requires that a wireless medium is determined to be busy when a reception level is equal to or greater than a minimum reception sensitivity level of a physical scheme. The apparatus includes a first processing unit and a second processing unit. The first processing unit is configured to set a value lower than a maximum transmission power of the first wireless communication scheme, for a maximum transmission power of the second wireless communication scheme and set a value greater than the minimum reception sensitivity level of the physical scheme, for a carrier sense level, when the second wireless communication scheme is used. The second processing unit is configured to carry out carrier sense using the carrier sense level.

Abstract: A receiving device of an embodiment has a receiver, a demultiplexer, and an interference detector. The receiver receives a multiplexed signal. The demultiplexer demultiplexes the multiplexed signal into a plurality of signals. The interference detector, with referring to bit transitions of the plurality of signals in a predetermined time period, detects interference in the multiplexed signal.

Abstract: A radio communication method stores a plurality MAC frames for each of a plurality of destinations. The method decides the longest transmission time of transmission times needed to transmit the plurality of MAC frames to each of the plurality of destinations within a fixed period. The method generates a plurality of physical frames for the plurality of destinations to transmit them at the same time by connecting the plurality of MAC frames and adding additional information to each connected MAC frame so as to be a frame length equivalent to a transmission time equal to the longest transmission time.

Abstract: According to one embodiment, a wireless communication device includes: a first transmitter configured to transmit a first frame to instruct transmission prohibition to a first wireless communication device, and to transmit a signal to a second wireless communication device during a period in which the transmission is prohibited; and a first receiver configured to receive power reception amount information corresponding to the signal after the signal is transmitted.