Abstract: When a wireless communication apparatus transmits a data frame requesting an ACK frame, it is expected that a receiver station will transmit the ACK frame. A preamble analyzer analyzes whether or not a preamble pattern added to the header of a received frame exists from the time it is expected that the ACK frame will be received. When a desired preamble pattern is detected, the preamble analyzer supplies instructions to start an operation of demodulating a reception signal to a demodulator via a controller.

Abstract: According to one embodiment, a wireless communication apparatus includes a first wireless communication unit, a second wireless communication unit, a reception power management unit, a frequency selection unit, and a frequency-hopping management unit. The second wireless communication unit performs wireless communication by means of a second wireless communication system different from the first communication system. The reception power management unit measures reception power. The frequency selection unit selects frequency-channel data enabling the second wireless communication unit to perform communication, on the basis of the reception power measured by the reception power management unit. The frequency-hopping management unit determines a frequency channel from the frequency-channel data selected by the frequency selection unit, if the second wireless communication unit performs communication by using a frequency hopping system.

Abstract: According to one embodiment, a transmission system includes a transmitter and a receiver. The transmitter includes a modulator configured to modulate transmission data at a chip rate to generate a modulation signal, and one or a plurality of light sources configured to emit visible light according to the modulation signal. The receiver includes a light receiver having one or more lines of light receiving elements to receive light in a first range including the visible light; and a demodulator configured to demodulate image data generated according to the light received by the light receiver to generate reception data corresponding to the transmission data. A following equation is satisfied ff<fm where fm is the chip rate, and ff is a frame rate of the light receiver.

Abstract: According to one embodiment, a semiconductor memory device includes a memory and a controller. The controller controls the memory, communicates with a host device via a first signal line and a second signal line, and receives data items to be written in the memory from the host device on the first and second signal lines in a first period. The same group number is assigned to two data items which flow in parallel on the first and second signal lines. The controller transmits to the host device a response packet including an indication of a group number assigned to an unsuccessfully received one of the data items.

Abstract: According to one embodiment, a wireless communication apparatus includes a reception unit, a storage unit, a transfer amount decision unit, and a first transfer control unit. The reception unit receives a first frame with a frame length of a first length using a first wireless method. The storage unit stores the first frame. The transfer amount decision unit sets, when a second length decided based on the first wireless method is smaller than the first length, a third length to be the second length, and sets, when the second length is not less than the first length, the third length to be a value not more than the first length. The first transfer control unit transfers transfer information including first information of the third length in the first frame to a first memory, and transfers the first frame by the first length to a second memory.

Abstract: A wireless communication apparatus includes a first module, a second module, an inhibit module, a calculation module, and a control module. The first module constitutes a first system. The first system transmits and receives first data to and from a first device. The second module constitutes a second system. The second system transmits and receives second data to and from a second device in each interval time-divided with determined transmission timing. The inhibit module generates inhibit periods for preventing the first module from communicating by use of the first data. The calculation module calculates an occupation time required for the transmission and reception of the first data. The control module compares the period between the inhibit periods adjacent to one another with the occupation time and, according to the comparison result, instructs the first device to stop or delay the transmission of the first data.

Abstract: A communication device of an example of the present invention comprises a first unit determining that whether a state is a first state indicating that a transmission medium is in use, a second state indicating that the transmission medium is not in use, or a third state indicating that whether or not the transmission medium is in use is being determined, and a second unit prohibiting a data transmission in the first and third states, and permitting the data transmission in the second state.

Abstract: A communication method includes causing a transmitter to apply error correcting or detecting code systems to multiple frames or packets and to transmit the multiple frames or packets in succession, causing a receiver to receive the transmitted frames or packets and to decode each of the frames or packets received, and causing the receiver to send an acknowledgment signal to the transmitter on the basis of the results of decoding of the frames or packets. The transmitter applies two or more error correcting or detecting code systems to the frames or packets.

Abstract: A wireless communication apparatus includes a first module, a second module, an inhibit module, a calculation module, and a control module. The first module constitutes a first system. The first system transmits and receives first data to and from a first device. The second module constitutes a second system. The second system transmits and receives second data to and from a second device in each interval time-divided with determined transmission timing. The inhibit module generates inhibit periods for preventing the first module from communicating by use of the first data. The calculation module calculates an occupation time required for the transmission and reception of the first data. The control module compares the period between the inhibit periods adjacent to one another with the occupation time and, according to the comparison result, instructs the first device to stop or delay the transmission of the first data.

Abstract: According to one embodiment, a memory device includes a first interface, a wireless communication unit, and first and second memories. The wireless communication unit is capable of wireless communication. The first memory is nonvolatile and capable of storing data. The second memory is capable of temporarily holding data received by the wireless communication unit. The wireless communication unit sets, by transmitting a first frame, a period during which data is not transmitted to the wireless communication unit when remaining capacity of the second memory has become smaller than first capacity.

Abstract: A radio communication system includes one master station which performs transmission without being controlled by another radio station and which is configured to independently set a channel for use in a radio communication, and at least one slave station which belongs to the one master station and whose radio communication channel used and transmission/reception operations are controlled by the master station. When detecting an interference signal which disturbs the radio communication during operation, the one master station or the at least one slave station sets a first modulation scheme applied to the radio communication to the same second modulation scheme as a modulation scheme used in broadcast in order to convey information necessary for an evasive action to move to another radio communication channel.

Abstract: A wireless communication device that includes a wireless communication unit that performs a wireless communication in a first mode using a first frequency band serving as a first communication channel, and performs the wireless communication in a second mode using a second frequency band including the first communication channel and a second communication channel that is adjacent to the first communication channel. Also included is a detection unit that monitors each of the first frequency band and the second frequency band, outputs a first detection signal when an interference signal is detected in the first frequency band and outputs a second detection signal when the interference signal is detected in the second frequency band. Further included is a determination unit that determines whether the interference signal is in the first communication channel or in the second communication channel based on the first and second detection signals.

Abstract: A wireless communication apparatus includes an M-number of (M is an integer of 2 or more) receiving portions connected to respective antennas, a frame analyzing section configured to analyze a reception signal received by the M-number of receiving portions, and a selecting section configured to select a receiving portion to be in service from the M-number of receiving portions. The selecting section selects a P-number of (P is an integer of from 0 to M) receiving portions from the M-number of receiving portions, based on an analysis result obtained by the frame analyzing section.

Abstract: A communication device of an example of the present invention comprises a first unit determining that whether a state is a first state indicating that a transmission medium is in use, a second state indicating that the transmission medium is not in use, or a third state indicating that whether or not the transmission medium is in use is being determined, and a second unit prohibiting a data transmission in the first and third states, and permitting the data transmission in the second state.

Abstract: According to one embodiment, a wireless communication device includes a first transmitting/receiving unit, a first physical processor, and a first MAC processor. The first transmitting/receiving unit transmits one first wireless signal and receives a second wireless signal by a first wireless communication method using a frequency band with a certain bandwidth. The first physical processor decodes the second wireless signal to obtain a frame and encodes a frame of the first wireless signal to be transmitted. The first MAC processor supplies a control frame generated by embedding a first frame to a MAC header of a second frame to the physical processor as the frame. The first frame is recognizable by the first wireless communication method and a second wireless communication method. The second frame is recognizable by the first wireless communication method but is not recognizable by the second wireless communication method.

Abstract: A communication device of an example of the present invention comprises a first unit determining that whether a state is a first state indicating that a transmission medium is in use, a second state indicating that the transmission medium is not in use, or a third state indicating that whether or not the transmission medium is in use is being determined, and a second unit prohibiting a data transmission in the first and third states, and permitting the data transmission in the second state.

Abstract: A wireless communication apparatus includes a transmission section and a control section. The transmission section transmits data using wireless communication. The control section controls a transmission rate for the transmission section. The control section limits data size of data to be transmitted to at most a prescribed value and requests a transmission acknowledgement, during a period from immediately after a change in the transmission rate until number of times that the transmission section transmits data reaches a prescribed number of times.

Abstract: A wireless communication device that includes a wireless communication unit that performs a wireless communication in a first mode using a first frequency band serving as a first communication channel, and performs the wireless communication in a second mode using a second frequency band including the first communication channel and a second communication channel that is adjacent to the first communication channel. Also included is a detection unit that monitors each of the first frequency band and the second frequency band, outputs a first detection signal when an interference signal is detected in the first frequency band and outputs a second detection signal when the interference signal is detected in the second frequency band. Further included is a determination unit that determines whether the interference signal is in the first communication channel or in the second communication channel based on the first and second detection signals.

Abstract: According to one embodiment, a wireless communication apparatus includes a reception unit, a storage unit, a transfer amount decision unit, and a first transfer control unit. The reception unit receives a first frame with a frame length of a first length using a first wireless method. The storage unit stores the first frame. The transfer amount decision unit sets, when a second length decided based on the first wireless method is smaller than the first length, a third length to be the second length, and sets, when the second length is not less than the first length, the third length to be a value not more than the first length. The first transfer control unit transfers transfer information including first information of the third length in the first frame to a first memory, and transfers the first frame by the first length to a second memory.

Abstract: A header analysis unit reads a parameter showing a format of a digital signal contained in a received signal. A received signal quality measurement unit measures a quality of the received signal. An awake/sleep control unit controls restart and sleep of a reception unit based on data from the header analysis unit and the received signal quality measurement unit. The awake/sleep control unit stops a reception operation for a period corresponding to a frame length when the quality of the leading portion of the received signal is less than a predetermined threshold.