Abstract: A wireless communications node, being included in a multi-hop route starting from a source node and terminating at a destination node, has a receiving part configured to receive signals including transmission data prepared by the source node and transferring the received signals to a succeeding node, a preparing part configured to prepare source node data including at least identification data of the source node based on a predetermined portion of the transmission data, and a reporting part configured to report the source node data and relay data to a management node that manages cost data of plural nodes included in an ad hoc network. The relay data include the cost data and station data including at least identification data of the wireless communications node.

Abstract: A wireless communications node, being included in a multi-hop route starting from a source node and terminating at a destination node, has a receiving part configured to receive signals including transmission data prepared by the source node and transferring the received signals to a succeeding node, a preparing part configured to prepare source node data including at least identification data of the source node based on a predetermined portion of the transmission data, and a reporting part configured to report the source node data and relay data to a management node that manages cost data of plural nodes included in an ad hoc network. The relay data include the cost data and station data including at least identification data of the wireless communications node.

Abstract: A radio communication system including a base station apparatus including a first memory to store a schedule for communication using each of a plurality of set values of a predetermined communication element in the physical layer, a first antenna to communicate with a terminal apparatus using a first set value of the plurality of set values in accordance with the schedule stored in the first memory, and a first processor to select a second set value of the plurality of set values if the condition of communication performed with the terminal apparatus by the first antenna using the first set value has deteriorated, and cause the first antenna to perform communication using the selected second set value in accordance with the schedule and the terminal apparatus including a second memory to store the schedule, a second antenna to communicate with the base station apparatus, and a second processor.

Abstract: A wireless communication device, including a radio transceiver data configured to transmit and to receive data packets to and from a base station, and a processor configured to compute a proportional hidden standby time being computed on the basis of at least two of from among a proportional exposed communication time, a proportional exposed collision time, and a proportional exposed standby time, to compute a predicted PER from the proportional hidden standby time computed; to compute a threshold value for the number of retransmission attempts on the basis of the predicted PER computed, and to cause the radio transceiver to repeat transmission of a data packet to the base station until the number of transmissions exceeds the threshold value computed in the case of failed transmission of a data packet to the base station by the radio transceiver.

Abstract: A phase tracking circuit includes a divider part dividing an input signal that includes data sub-carriers and pilot sub-carriers into groups so that each of the groups includes at least one of the pilot sub-carriers, and a correcting part correcting phases of data sub-carriers of the input signal included in one of the groups on the basis of an amount of phase rotation of the at least one of the pilot sub-carriers included in the above one of the groups.

Abstract: A wireless communication device includes a transmitter configured to transmit test signals a predetermined number of times at an interval shorter than a transmission interval of data signals and a processor configured to measure reception status of a plurality of acknowledgement signals transmitted back in response to the respective test signals transmitted by the transmitter.

Abstract: In a wireless communication apparatus in a time division duplex system, a transmission signal generation unit generates a transmission signal. A power amplifying device amplifies the generated transmission signal. A control signal generation device generates a drain voltage control signal for control of the drain voltage of the power amplifying device, and a gate voltage control signal for control of the gate voltage of the power amplifying device. The switch unit switches off the drain power supply of the power amplifying device during reception in the time division duplex system according to the drain voltage control signal. In addition, the power amplifying device sets a higher gate voltage during reception in the time division duplex system higher than during transmission according to the gate voltage control signal.

Abstract: An IQ imbalance correction method includes transmitting a plurality of pairs of RF training signals in installments by pairing RF training signals symmetric with respect to a center frequency on a frequency axis; setting a reception local frequency to change to a frequency that is suitable to receive, via an internal path, each of the plurality of pairs of RF training signals transmitted in installments, and suitable to convert the each of the plurality of pairs of RF training signals into IF training signals; and performing quadrature demodulation on the IF training signals, respectively, in a digital circuit area to generate BB training signals.

Abstract: A disclosed group delay characteristic correcting device corrects group delay characteristics of an analog low-pass filter used to remove aliasing of a digital-analog converter or an analog-digital converter. The group delay characteristic correcting device includes a digital signal processing unit configured to have an all-pass phase circuit at a stage previous to the digital-analog converter or at a stage subsequent to the analog-digital converter so as to correct the group delay characteristics of the analog low-pass filter.

Abstract: A wireless communications node, being included in a multi-hop route starting from a source node and terminating at a destination node, has a receiving part configured to receive signals including transmission data prepared by the source node and transferring the received signals to a succeeding node, a preparing part configured to prepare source node data including at least identification data of the source node based on a predetermined portion of the transmission data, and a reporting part configured to report the source node data and relay data to a management node that manages cost data of plural nodes included in an ad hoc network. The relay data include the cost data and station data including at least identification data of the wireless communications node.

Abstract: Memory stores data. A processing unit collects various data and stores the data in the memory. A power source unit provides electric power needed by the processing unit for collecting the data and storing the data in the memory. A receiver unit conducts reception or transmission of radio signals. The receiver unit controls the power source unit so as to make it supply electric power to the processing unit when a received radio signal includes a prescribed first signal, and when a received radio signal includes a prescribed second signal, the receiver unit reads the data stored in the memory so as to transmit it as a radio signal.

Abstract: A disclosed group delay characteristic correcting device corrects group delay characteristics of an analog low-pass filter used to remove aliasing of a digital-analog converter or an analog-digital converter. The group delay characteristic correcting device includes a digital signal processing unit configured to have an all-pass phase circuit at a stage previous to the digital-analog converter or at a stage subsequent to the analog-digital converter so as to correct the group delay characteristics of the analog low-pass filter.

Abstract: A phase tracking circuit includes a divider part dividing an input signal that includes data sub-carriers and pilot sub-carriers into groups so that each of the groups includes at least one of the pilot sub-carriers, and a correcting part correcting phases of data sub-carriers of the input signal included in one of the groups on the basis of an amount of phase rotation of the at least one of the pilot sub-carriers included in the above one of the groups.

Abstract: In a wireless communication apparatus in a time division duplex system, a transmission signal generation unit generates a transmission signal. A power amplifying device amplifies the generated transmission signal. A control signal generation device generates a drain voltage control signal for control of the drain voltage of the power amplifying device, and a gate voltage control signal for control of the gate voltage of the power amplifying device. The switch unit switches off the drain power supply of the power amplifying device during reception in the time division duplex system according to the drain voltage control signal. In addition, the power amplifying device sets a higher gate voltage during reception in the time division duplex system higher than during transmission according to the gate voltage control signal.

Abstract: A MIMO wireless communication system and wireless communication apparatuses are disclosed that increase the practically usable communication channel capacity in the Shannon channel capacity that determines the ratio of maximum signal transmission speed to frequency. Each wireless communication apparatus includes antenna units that transmit and receive radio frequency signals, and a weight controlling unit that provides weights with respect to the antenna units. The antenna units are formed by adaptive array antenna units that can change the directivity by varying weights with respect to antenna elements.

Abstract: A mobile communication terminal used in a mobile communication system providing mobile communicating service in a first frequency band is disclosed. The mobile communication terminal comprises a first signal processing circuit for processing signals for the mobile communication service; a second signal processing circuit for processing signals for radio tag communicating in a second frequency band; and an antenna commonly used by the first and second signal processing circuits. The impedance of the antenna is matched with the first signal processing circuit in the first frequency band and matched with the second signal processing circuit in the second frequency band.

Abstract: A radar equipment of the present invention amplifies a reception signal with feedback based on the delay amount obtained from the correlation detection result. Accordingly, it becomes possible to maintain the reception signal (demodulated signal) level to a proper level depending on the distance to the target, and accurate measurement can be achieved with high precision. Namely, the reception signal is amplified depending on the distance to the target, and the reception signal level is made within a tolerable input level range of a logic circuit for performing correlation calculation. In particular, during tracking the target, even when a reflected signal is received with abrupt level variation caused by noise or a reflected signal from an object other than the target, incorrect detection of the target can be avoided by disabling the correlation calculation.

Abstract: A MIMO wireless communication system and wireless communication apparatuses are disclosed that increase the practically usable communication channel capacity in the Shannon channel capacity that determines the ratio of maximum signal transmission speed to frequency. Each wireless communication apparatus includes antenna units that transmit and receive radio frequency signals, and a weight controlling unit that provides weights with respect to the antenna units. The antenna units are formed by adaptive array antenna units that can change the directivity by varying weights with respect to antenna elements.

Abstract: A MIMO wireless communication system and wireless communication apparatuses are disclosed that increase the practically usable communication channel capacity in the Shannon channel capacity that determines the ratio of maximum signal transmission speed to frequency. Each wireless communication apparatus includes antenna units that transmit and receive radio frequency signals, and a weight controlling unit that provides weights with respect to the antenna units. The antenna units are formed by adaptive array antenna units that can change the directivity by varying weights with respect to antenna elements.

Abstract: The invention relates to a radar device for measuring a relative distance to a target. It is an object of the invention to precisely determine the relative distance to the target in a wide range. The radar device according to the invention generates a second pulse by demodulating a signal arriving from a target as a response to a wave signal modulated with a first pulse. The radar device evaluates, as the relative distance to the target, such two different instances that an absolute value of a deviation of a ratio of two instantaneous values of the second pulse from a reference value as a ratio of two instantaneous values of the first pulse is to be minimum. The respective two instantaneous values are with a predetermined interval therebetween on a time axis.