Abstract: A transmission device includes a memory, and a processor coupled to the memory and configured to sample a first transmission signal obtained by performing baseband processing on a baseband signal, output the sampled first transmission signal; generate a peak reduction signal that reduces a signal level of all samples in such a manner that the signal level of all the samples of a peak of the first transmission signal with the signal level equal to or higher than a predetermined threshold is reduced to be lower than the threshold, output a second transmission signal obtained by reducing the peak of the first transmission signal with the peak reduction signal, and transmit the second transmission signal.

Abstract: A wireless communication device that implements beamforming includes: a storage, a processor, and a radio circuit. The storage stores directivity information that indicates a directivity of a radio intensity obtained when beams are formed in a plurality of main lobe directions designated in advance. The processor calculates, based on the directivity information, an interference to a first beam from a second beam when an instruction to form the first beam and the second beam is given. The first beam is configured to transmit a first signal in a first main lobe direction. The second beam is configured to transmit a second signal in a second main lobe direction. The processor generates, based on the calculated interference, a cancellation signal for canceling the second signal in the first main lobe direction. The radio circuit transmits the first signal and the cancellation signal.

Abstract: A wireless communication device that implements beamforming includes: a storage, a processor, and a radio circuit. The storage stores directivity information that indicates a directivity of a radio intensity obtained when beams are formed in a plurality of main lobe directions designated in advance. The processor calculates, based on the directivity information, an interference to a first beam from a second beam when an instruction to form the first beam and the second beam is given. The first beam is configured to transmit a first signal in a first main lobe direction. The second beam is configured to transmit a second signal in a second main lobe direction. The processor generates, based on the calculated interference, a cancellation signal for canceling the second signal in the first main lobe direction. The radio circuit transmits the first signal and the cancellation signal.

Abstract: A wireless apparatus configured to be cascaded to another wireless apparatus through a transmission path and to be coupled to an antenna multiplexer, the another wireless apparatus being coupled to the antenna multiplexer, the wireless apparatus includes a processor configured to specify a first time length for a first transmission signal having a first frequency band to pass through the wireless apparatus, specify a second time length for a second transmission signal having a second frequency band to pass through the wireless apparatus, the transmission path, and the another wireless apparatus, specify a difference between the first time length and the second time length, delay the second transmission signal by the specified difference, generate a cancellation signal for an intermodulation distortion that occurs in a received signal due to intermodulation between the first transmission signal and the second transmission signal, and combine the cancellation signal with the received signal.

Abstract: A wireless apparatus configured to be cascaded to another wireless apparatus through a transmission path and to be coupled to an antenna multiplexer, the another wireless apparatus being coupled to the antenna multiplexer, the wireless apparatus includes a processor configured to specify a first time length for a first transmission signal having a first frequency band to pass through the wireless apparatus, specify a second time length for a second transmission signal having a second frequency band to pass through the wireless apparatus, the transmission path, and the another wireless apparatus, specify a difference between the first time length and the second time length, delay the second transmission signal by the specified difference, generate a cancellation signal for an intermodulation distortion that occurs in a received signal due to intermodulation between the first transmission signal and the second transmission signal, and combine the cancellation signal with the received signal.

Abstract: There is provided a distortion cancellation apparatus including a memory, and a processor coupled to the memory and the processor configured to acquire transmission signals to be wirelessly transmitted at different frequencies, acquire a received signal to which intermodulation signals generated by the transmission signals are added, generate cancellation signals respectively corresponding to the intermodulation signals added to the received signal by using an arithmetic expression including the transmission signals and the received signal, calculate an influence rate indicating a magnitude of a signal level of each of the intermodulation signals within a band of the received signal, and first cancel an intermodulation signal out of the intermodulation signals added to the received signal wherein the influence rate of the intermodulation signal first canceled is high out of the intermodulation signals added to the received signal, based on the cancellation signals.

Abstract: There is provided a distortion cancellation apparatus including a memory, and a processor coupled to the memory and the processor configured to acquire a plurality of transmission signals to be wirelessly transmitted at different frequencies, acquire a first plurality of reception signals to which an intermodulation signal generated due to the plurality of transmission signals wirelessly transmitted is added, multiplex at least one set of transmission signals among the plurality of transmission signals to be wirelessly transmitted so as to generate at least one multiplexed transmission signal, generate a cancellation signal for canceling the intermodulation signal, based on the at least one multiplexed transmission signal and the first plurality of reception signals, and cancel the intermodulation signal added to the first plurality of reception signals, based on the cancellation signal.

Abstract: A communication device includes a transmitter to transmit a radio transmission signal having a frequency different from a frequency of a radio transmission signal transmitted by another transmitter, a receiver to receive a receiving signal including a primary signal and a first passive intermodulation signal generated by radio transmission signals, a memory, and a processor coupled to the memory and the processor to calculate a power of the primary signal, update a first coefficient for generating a cancel signal for canceling the first passive intermodulation signal, based on the receiving signal and transmission signals to be transmitted, generate the cancel signal based on the transmission signals and the first coefficient, and combine the receiving signal and the cancel signal, wherein the processor is further to adjust a step coefficient, which is a time constant in case of updating the first coefficient, based on the power of the calculated primary signal.

Abstract: A passive intermodulation (PIM) canceller of a communication device includes a combining unit, a replica generating unit, and a delay measuring instrument. The replica generating unit generates an intermodulation signal based on the amount of delay of each transmission signal. The combining unit cancels out the intermodulation signal from the reception signal using the generated intermodulation signal. The delay measuring instrument delays a transmission signal x2 included in a plurality of transmission signals by different first amounts of delay. The delay measuring instrument generates an intermediate signal Sm1 by multiplying the delayed transmission signal x2 to the reception signal. The delay measuring instrument calculates, based on the correlation values of the intermediate signal Sm1 corresponding to each first amount of delay and a transmission signal x1 included in the plurality of transmission signals, the amount of delay of the transmission signal x1 with respect to the intermodulation signal.

Abstract: A delay measuring instrument includes a generating unit and a calculating unit. The generating unit is, for example, a multiplier. The calculating unit is, for example, a maximum value detecting unit. The generating unit generates an intermediate signal by multiplying one of transmission signals or the complex conjugate of the one of the transmission signals included in the plurality of transmission signals that are transmitted at different frequencies by a reception signal that includes therein an intermodulation signal generated by the plurality of the transmission signals. The calculating unit calculates, based on a correlation value between the intermediate signal and the other one of the transmission signals included in the plurality of the transmission signals, an amount of delay of the other one of the transmission signals with respect to the intermodulation signal.

Abstract: A distortion cancel device includes: a first acquiring unit that acquires a plurality of transmission signals including at least two transmission signals that are wirelessly transmitted at an identical frequency; a second acquiring unit that acquires a reception signal to which an intermodulation signal generated due to the transmission signals is attached; and a processor that executes a process including: determining a ratio of the transmission signals acquired by the first acquiring unit and wirelessly transmitted at the identical frequency; generating a ratio signal for each frequency from the transmission signals in accordance with the determined ratio; generating a cancel signal corresponding to the intermodulation signal by using an arithmetic expression that uses the generated ratio signal; and combining the generated cancel signal with the reception signal acquired by the second acquiring unit.

Abstract: A distortion cancellation device includes a first acquiring unit that acquires a plurality of transmission signals that are wirelessly transmitted at different frequencies; a second acquiring unit that acquires a reception signal to which an intermodulation signal generated due to the plurality of the transmission signals is added; and a processor that executes a process including acquiring a gain difference between the plurality of the transmission signals generated when the plurality of the transmission signals acquired by the first acquiring unit is sent to a generation source of the intermodulation signal, generating, by an arithmetic expression using both the acquired gain difference and the plurality of the transmission signals, a cancellation signal associated with the intermodulation signal, and combining the generated cancellation signal with the reception signal acquired by the second acquiring unit.

Abstract: A wireless communication apparatus includes a generating unit, a detecting unit, and a suppressing unit. The generating unit generates, using signals at multiple carrier frequencies that are different from each other, a replica signal for passive inter modulation distortion that occurs in a reception signal from a terminal due to the transmission of a multicarrier signal that includes the signals at the multiple carrier frequencies. The detecting unit detects the correlation value between the replica signal for the passive inter modulation distortion and the reception signal. The suppressing unit suppresses the peak of the multicarrier signal when the correlation value is equal to or more than the threshold.

Abstract: A radio device includes: a processor that outputs a transmission signal containing a plurality of signals that are transmitted at different frequencies; an amplifier that amplifies the transmission signal output from the processor; and a transmitter/receiver that transmits by radio the transmission signal amplified by the amplifier and that receives by radio a signal having a frequency different from a frequency of the transmission signal. The processor generates a cancel signal based on the plurality of signals contained in the transmission signal, the cancel signal corresponding to an intermodulation distortion that occurs due to intermodulation among the plurality of signals, and the transmitter/receiver synthesizes the cancel signal generated by the processor with the transmission signal amplified by the amplifier.

Abstract: A radio device includes: a processor that outputs a transmission signal containing a plurality of signals that are transmitted at different frequencies; an amplifier that amplifies the transmission signal output from the processor; and a transmitter/receiver that transmits by radio the transmission signal amplified by the amplifier and that receives by radio a signal having a frequency different from a frequency of the transmission signal. The processor generates a cancel signal based on the plurality of signals contained in the transmission signal, the cancel signal corresponding to an intermodulation distortion that occurs due to intermodulation among the plurality of signals, and the transmitter/receiver synthesizes the cancel signal generated by the processor with the transmission signal amplified by the amplifier.

Abstract: A wireless communication apparatus includes a generating unit, a detecting unit, and a suppressing unit. The generating unit generates, using signals at multiple carrier frequencies that are different from each other, a replica signal for passive inter modulation distortion that occurs in a reception signal from a terminal due to the transmission of a multicarrier signal that includes the signals at the multiple carrier frequencies. The detecting unit detects the correlation value between the replica signal for the passive inter modulation distortion and the reception signal. The suppressing unit suppresses the peak of the multicarrier signal when the correlation value is equal to or more than the threshold.

Abstract: A communication device includes a sending unit that sends a plurality of signals that are to be wirelessly sent with different frequencies; an acquiring unit that acquires a reception signal to which an intermodulation signal that is produced due to intermodulation of the plurality of signals is added; and a processor that is connected to the sending unit and the acquiring unit. The processor generates, on the basis of the plurality of signals sent by the sending unit, a cancellation signal corresponding to the intermodulation signal and combines the generated cancellation signal with the reception signal acquired by the acquiring unit.