Abstract: A base station serving as a transmission apparatus includes a plurality of transmission antennas capable of forming beams directed to a plurality of terminals, which are reception apparatus, and a precoder configured to perform outer precoding on transmission signals transmitted from the plurality of transmission antennas. The plurality of terminals include at least one first reception apparatus, which are transmission destinations of the transmission signals, and second reception apparatus, which are reception apparatus other than the first reception apparatus. The precoder performs outer precoding on the transmission signals transmitted from the plurality of transmission antennas so that received power in the second reception apparatus among the plurality of reception apparatus is equal to or less than a threshold.

Abstract: A transmitting apparatus according to the present invention includes transmission antennas capable of forming a plurality of beams respectively directed to a plurality of terminals and a precoder unit that performs precoding on signals transmitted from the transmission antennas such that received power in the terminals excluding a desired terminal serving as a transmission destination of a transmission signal and two or more IUI terminals, which are the terminals other than the desired terminal, is equal to or smaller than a threshold.

Abstract: A transmitting apparatus includes transmission antennas capable of forming a plurality of beams respectively directed to a plurality of terminals and a precoder unit that performs precoding on signals transmitted from the transmission antennas such that received power in the terminals excluding a desired terminal serving as a transmission destination of a transmission signal and IUI terminals, which are the terminals other than the desired terminal, is equal to or smaller than a threshold.

Abstract: A wireless communication apparatus, for example a wireless base station that spatially multiplexes data for transmission, includes plural array antennas and a beam shape controller that controls the array antennas to form beams of different shapes and each transmit signals for communication quality measurement in an area to be covered by the apparatus, and determines an initial value of a beam shape to be used in data transmission to a counterpart device that has received the signal for communication quality measurement, and after the initial value is determined, repeatedly executes processing to control the array antennas to tentatively change a beam shape in use in data transmission to the counterpart device, and redetermine a beam shape to be used in data transmission to the counterpart device, based on communication quality measured when the post-tentative-change beam shape is used and communication quality measured when the pre-tentative-change beam shape is used.

Abstract: A radio transmission apparatus includes a plurality of antennas each having an amplifier, a transmission signal generation unit (modulation units, S/P units, and FFT units) which generates a signal to be transmitted to a terminal via the antennas, and a weighting processing unit (a precoder unit, a maximum power calculation unit, and multipliers) which executes a weighting process on a signal to be transmitted to the terminal, which has been generated by the transmission signal generation unit, based on channel state information between the radio transmission apparatus and the terminal and an output limit value of the amplifier.

Abstract: A radio transmission apparatus includes a plurality of antennas each having an amplifier, a transmission signal generation unit (modulation units, S/P units, and FFT units) which generates a signal to be transmitted to a terminal via the antennas, and a weighting processing unit (a precoder unit, a maximum power calculation unit, and multipliers) which executes a weighting process on a signal to be transmitted to the terminal, which has been generated by the transmission signal generation unit, based on channel state information between the radio transmission apparatus and the terminal and an output limit value of the amplifier.

Abstract: A transmitting apparatus includes a first signal generating unit that generates, on the basis of data a first signal transmitted by single carrier block transmission; a second signal generating unit that generates, on the basis of an RS, a second signal transmitted by orthogonal frequency division multiplex transmission; a switching operator that selects and outputs the second signal in a first transmission period and selects and outputs the first signal in a second transmission period; an antenna that transmits the signal output from the switching operator; and a control-signal generating unit that controls the second signal generating unit such that, in the first transmission period, the RS is arranged in a frequency band allocated for transmission of the RS from the transmitting apparatus among frequency bands usable in OFDM.

Abstract: A transmitting apparatus includes transmission antennas capable of forming a plurality of beams respectively directed to a plurality of terminals and a precoder unit that performs precoding on signals transmitted from the transmission antennas such that received power in the terminals excluding a desired terminal serving as a transmission destination of a transmission signal and IUI terminals, which are the terminals other than the desired terminal, is equal to or smaller than a threshold.

Abstract: A transmitting apparatus according to the present invention includes transmission antennas capable of forming a plurality of beams respectively directed to a plurality of terminals and a precoder unit that performs precoding on signals transmitted from the transmission antennas such that received power in the terminals excluding a desired terminal serving as a transmission destination of a transmission signal and two or more IUI terminals, which are the terminals other than the desired terminal, is equal to or smaller than a threshold.

Abstract: A radio communication apparatus includes a FH control unit controlling frequency hopping for changing a frequency channel for each frame, a carrier sense unit performing carrier sense, for each of slots obtained by dividing the frame, a modulating unit determining transmission timing in the slot on the basis of a result of the carrier sense, a successive-transmission control unit generating a plurality of pieces of same data by duplicating transmission data, and a scheduler allocating, for each slot, a different communication time period to each mobile station. The radio communication apparatus transmits, on the basis of an allocation result of the communication time period, the transmission timing, and the instruction by the hopping control unit, the same data generated from same transmission data to the mobile stations in the frames different from each other and notifies the mobile stations of the allocation result.

Abstract: An in-vehicle device stores a Wake Up pattern, which notifies a mobile device of a start of communication, in an area before a data storage area of a frame and transmits the frame, the mobile device includes a modulation/demodulation circuit and a microcomputer that perform a predetermined reception process on a reception signal, a pattern determination circuit that, when the reception signal includes a Wake Up pattern, determines to start communication and activates the modulation/demodulation circuit and the microcomputer, a power detection circuit that detects power of the reception signal, and, when power is detected for a certain period of time or longer, activates the pattern determination circuit, and a Wake-Up control unit that activates the power detection circuit for a predetermined time with a constant period during a time period other than during communication.

Abstract: A radio communication apparatus includes antennas, transceiver units respectively connected to the antennas, and a radio control unit that controls the transceiver units, simultaneously inputs same transmission data to the transceiver units, and instructs, every switching cycle of frequency hopping, the transceiver units to start check processing for an idle state of frequency channels. The transceiver units respectively include hopping control units that switch the frequency channels every fixed time in synchronization with a communication partner and control such that each of the transceiver units uses a different frequency at the same hour. When determining that a frequency channel is in an idle state before a predetermined time elapses from the start of the check processing for an idle state, the transceiver units transmit the transmission data to the communication partner using the frequency channel.

Abstract: A radio communication apparatus includes antennas, transceiver units respectively connected to the antennas, and a radio control unit that controls the transceiver units, simultaneously inputs same transmission data to the transceiver units, and instructs, every switching cycle of frequency hopping, the transceiver units to start check processing for an idle state of frequency channels. The transceiver units respectively include hopping control units that switch the frequency channels every fixed time in synchronization with a communication partner and control such that each of the transceiver units uses a different frequency at the same hour. When determining that a frequency channel is in an idle state before a predetermined time elapses from the start of the check processing for an idle state, the transceiver units transmit the transmission data to the communication partner using the frequency channel.

Abstract: A radio communication apparatus includes a FH control unit controlling frequency hopping for changing a frequency channel for each frame, a carrier sense unit performing carrier sense, for each of slots obtained by dividing the frame, a modulating unit determining transmission timing in the slot on the basis of a result of the carrier sense, a successive-transmission control unit generating a plurality of pieces of same data by duplicating transmission data, and a scheduler allocating, for each slot, a different communication time period to each mobile station. The radio communication apparatus transmits, on the basis of an allocation result of the communication time period, the transmission timing, and the instruction by the hopping control unit, the same data generated from same transmission data to the mobile stations in the frames different from each other and notifies the mobile stations of the allocation result.

Abstract: An in-vehicle device stores a Wake Up pattern, which notifies a mobile device of a start of communication, in an area before a data storage area of a frame and transmits the frame, the mobile device includes a modulation/demodulation circuit and a microcomputer that perform a predetermined reception process on a reception signal, a pattern determination circuit that, when the reception signal includes a Wake Up pattern, determines to start communication and activates the modulation/demodulation circuit and the microcomputer, a power detection circuit that detects power of the reception signal, and, when power is detected for a certain period of time or longer, activates the pattern determination circuit, and a Wake-Up control unit that activates the power detection circuit for a predetermined time with a constant period during a time period other than during communication.

Abstract: Conventionally, if the number of transmission antennas is greater than that of reception antennas, different signals simultaneously transmitted from the transmission antennas cannot be separated from one another at the receiving end, resulting in a significant degradation of received-signal quality. A transmitter and a receiver each have a plurality of antennas. The transmitter transmits a pilot signal. The receiver receives the pilot signal, calculates transmission-related information corresponding to the pilot signal, selects, based on this calculated information, a transmission signal to be used by the transmitter, and notifies the transmitter of the selected signal. The transmitter selects, from the informed transmission signal, transmission antennas and uses the selected antennas to transmit information signals, so that a signal separation can be easily performed at the receiving end.

Abstract: When transmitting an RF signal for power supply or a pulse signal for data transmission, amplification is made in such a manner that the peak power of the RF signal becomes greater than the peak power of the pulse signal. Thus transmitting the RF signal with the greater peak power enables charging of a capacitor 23 of noncontact wireless communication equipment 2 even if the distance to the noncontact wireless communication equipment 2 is long.

Abstract: A base station of a radio communication system emits a radio wave having the same frequency by time division toward a plurality of specific areas from a plurality of antenna elements by using a multiple-beam antenna to form a plurality of spot beams, and transmits broadcast information through a plurality of beacon channels. Upon reception of the broadcast information, a terminal that exists in any one of the plurality of specific areas selects an optimum beacon channel, and transmits a communication establishment request and a bandwidth request to the base station through a request channel corresponding to information for identifying the antenna element, which is included in the broadcast information received through the selected optimum beacon channel. Upon reception of the requests, the base station schedules, when a channel is to be allocated, a channel allocation time including downlink and uplink data bandwidths and the like.

Abstract: Conventionally, if the number of transmission antennas is greater than that of reception antennas, different signals simultaneously transmitted from the transmission antennas cannot be separated from one another at the receiving end, resulting in a significant degradation of received-signal quality. A transmitter and a receiver each have a plurality of antennas. The transmitter transmits a pilot signal. The receiver receives the pilot signal, calculates transmission-related information corresponding to the pilot signal, selects, based on this calculated information, a transmission signal to be used by the transmitter, and notifies the transmitter of the selected signal. The transmitter selects, from the informed transmission signal, transmission antennas and uses the selected antennas to transmit information signals, so that a signal separation can be easily performed at the receiving end.

Abstract: A radio communication method and apparatus generate a plurality of information signals and transmit the signals to a communication partner from a plurality of antennas. A plurality of combination of signals to be transmitted are selected. A transmission evaluation value is determined based on the signal noise ratio of each signal. After all combinations are evaluated, a transmission format suitable for sending a combination of signals is determined based on a highest evaluation value.