Abstract: A multiantenna communication device forms a directional beam by adding an antenna weight to respective signals of a plurality of antenna elements. The multiantenna communication device includes: a processor that executes performing distortion compensation on a transmission signal by using a distortion compensation coefficient; a plurality of power amplifiers that are provided corresponding to the antenna elements, and that amplify the transmission signal subjected to the distortion compensation by the processor; a multiplexer that multiplexes signals output from the power amplifiers to feed back; and an analog/digital (A/D) converter that A/D converts a multiplex feedback signal that is obtained by the multiplexer, wherein the processor executes updating the distortion compensation coefficient by using the multiplex feedback signal A/D converted by the A/D converter and the transmission signal.

Abstract: A multiantenna communication device forms a directional beam by adding an antenna weight to respective signals of a plurality of antenna elements. The multiantenna communication device includes: a processor that executes performing distortion compensation on a transmission signal by using a distortion compensation coefficient; a plurality of power amplifiers that are provided corresponding to the antenna elements, and that amplify the transmission signal subjected to the distortion compensation by the processor; a multiplexer that multiplexes signals output from the power amplifiers to feed back; and an analog/digital (A/D) converter that A/D converts a multiplex feedback signal that is obtained by the multiplexer, wherein the processor executes updating the distortion compensation coefficient by using the multiplex feedback signal A/D converted by the A/D converter and the transmission signal.

Abstract: There is provided a communication device configured to limit a frequency band of a transmission signal including a plurality of signals to be wirelessly transmitted via an antenna at different frequencies to a frequency band allocated to the transmission signal in advance, generate, based on the plurality of signals included in the transmission signal, a cancellation signal corresponding to intermodulation distortion to be generated by intermodulation of the plurality of signals, transmit the transmission signal having the limited frequency band for the antenna and transmit a signal received via the antenna, and synthesize the transmission signal with the cancellation signal, wherein the synthesized transmission signal is wirelessly transmitted via the antenna at the different frequencies.

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: An amplification device that amplifies two signals split from an input signal and synthesizes the amplified signals, the amplification device includes a first adjuster that adjusts a phase difference between the two signals by using power of an output signal acquired by synthesizing the two signals, and a second adjuster that adjusts phases of the two signals by using an Amplitude Modulation (AM)-Phase Modulation (PM) characteristic that indicates a relationship between the power of the input signal and the phase of the output signal in a state of fixing the phase difference adjusted by the first adjuster.

Abstract: A distortion compensation apparatus includes a retention unit that retains a coefficient for distortion compensation for each of a plurality of time segments of a burst signal that keeps a constant power level, and a distortion compensation unit that, by using a coefficient for a time segment that corresponds to elapsed time from a head of the burst signal among the coefficients retained by the retention unit, executes distortion compensation for the time segment.

Abstract: A radio communication device includes: an instantaneous coefficient acquisition unit that acquires an instantaneous coefficient that corrects an instantaneous change contained in a burst distortion corresponding to an elapsed time from a top of a burst signal in which a constant power level continues and instantaneously changes the power level of the burst signal; an average coefficient acquisition unit that acquires an average coefficient that corrects an average change contained in the burst distortion and gradually changes the power level of the burst signal from the top to an end of the burst signal; a synthesizer that synthesizes the instantaneous coefficient acquired by the instantaneous coefficient acquisition unit with the average coefficient acquired by the average coefficient acquisition unit; and a corrector that uses a correction coefficient obtained from the synthesizing by the synthesizer to correct the burst distortion occurring in the burst signal.

Abstract: An amplification apparatus includes a separator configured to separate an input signal into a first signal and a second signal, a first and second amplifiers amplify the first and second signal, a storage, and a processor coupled to the storage and configured to adjust a phase of the second signal on the basis of a first phase value corresponding to a power value of the input signal or a second phase value set within a period in which the first phase value is updated, calculate a power value of an output signal that is synthesis of an output of the first amplifier and an output of the second amplifier, and update the first phase value to the second phase value after the change of the power value of the calculated output signal when the first phase value is the power value of the input signal.

Abstract: A radio communication device includes: an instantaneous coefficient acquisition unit that acquires an instantaneous coefficient that corrects an instantaneous change contained in a burst distortion corresponding to an elapsed time from a top of a burst signal in which a constant power level continues and instantaneously changes the power level of the burst signal; an average coefficient acquisition unit that acquires an average coefficient that corrects an average change contained in the burst distortion and gradually changes the power level of the burst signal from the top to an end of the burst signal; a synthesizer that synthesizes the instantaneous coefficient acquired by the instantaneous coefficient acquisition unit with the average coefficient acquired by the average coefficient acquisition unit; and a corrector that uses a correction coefficient obtained from the synthesizing by the synthesizer to correct the burst distortion occurring in the burst signal.

Abstract: A distortion compensation apparatus includes a retention unit that retains a coefficient for distortion compensation for each of a plurality of time segments of a burst signal that keeps a constant power level, and a distortion compensation unit that, by using a coefficient for a time segment that corresponds to elapsed time from a head of the burst signal among the coefficients retained by the retention unit, executes distortion compensation for the time segment.

Abstract: A power amplifier apparatus includes an amplifier configured to amplify an input signal converted into an analog signal, a distortion compensator circuitry configured to perform a pre-distortion process to an input signal at a second sampling rate higher than a first sampling rate at which the input signal is converted into an analog signal, a remover configured to remove a frequency component exceeding a frequency band corresponding to the first sampling rate from the input signal subjected to the pre-distortion process, a first rate converter configured to convert a sampling rate of the input signal from which the frequency component is removed from the second sampling rate to the first sampling rate, and a first signal converter configured to convert the input signal the sampling rate of which is converted into an analog signal at the first sampling rate to supply the input signal converted into the analog signal to the amplifier.

Abstract: A wireless transmission apparatus includes an amplifier that amplifies power of a multicarrier signal, a first frequency shift unit that performs a first frequency shift on a first signal fed back from the amplifier on the basis of carrier frequencies of the multicarrier signal to output a second signal after the first frequency shift, a band limiting unit that performs frequency band limitation on the second signal to output a third signal after the frequency band limitation, and a distortion compensation device that compensates nonlinear distortion of the amplifier on the basis of the third signal.

Abstract: A distortion compensation apparatus that compensates nonlinear distortion of an amplifier that amplifies power of a multi-carrier signal includes a band limiting unit that places a first frequency band limitation on a first signal fed back from the amplifier to output a second signal after the first frequency band limitation, a decision unit that decides a first cutoff frequency of the first frequency band limitation based on a carrier interval of the multi-carrier signal, and an updating unit that updates a distortion compensation coefficient to be used for compensation of the nonlinear distortion, based on an error between the second signal and the multi-carrier signal.

Abstract: An amplifying device including: a first amplifier configured to generate a first output signal by amplifying an input signal, a second amplifier configured to generate a second output signal by amplifying the first output signal, and a processor configured to perform a first compensation by compensating a distortion for the second amplifier in accordance with the first output signal and the second output signal.

Abstract: A distortion compensation device includes: a distortion compensator configured to output, to a power amplifier, a predistortion signal obtained by performing distortion compensation processing on a transmission signal by using a distortion compensation coefficient, wherein the distortion compensator limits bands of a reference signal and a feedback signal so that the bands fall in a pass band and updates the distortion compensation coefficient based on an error between the reference signal and the feedback signal, the reference signal corresponding to the predistortion signal, the feedback signal corresponding to an output feedback of the power amplifier.

Abstract: A wireless transmission apparatus includes an amplifier that amplifies power of a multicarrier signal, a first frequency shift unit that performs a first frequency shift on a first signal fed back from the amplifier on the basis of carrier frequencies of the multicarrier signal to output a second signal after the first frequency shift, a band limiting unit that performs frequency band limitation on the second signal to output a third signal after the frequency band limitation, and a distortion compensation device that compensates nonlinear distortion of the amplifier on the basis of the third signal.

Abstract: A distortion compensation apparatus that compensates nonlinear distortion of an amplifier that amplifies power of a multi-carrier signal includes a band limiting unit that places a first frequency band limitation on a first signal fed back from the amplifier to output a second signal after the first frequency band limitation, a decision unit that decides a first cutoff frequency of the first frequency band limitation based on a carrier interval of the multi-carrier signal, and an updating unit that updates a distortion compensation coefficient to be used for compensation of the nonlinear distortion, based on an error between the second signal and the multi-carrier signal.

Abstract: A distortion compensation apparatus for performing distortion compensation processing by applying the inverse properties of distortion properties of the power amplifier to a transmission signal to be input to a power amplifier, includes a plurality of distortion compensation coefficient storage units configured to store a plurality of distortion compensation coefficients used for the distortion compensation processing, an offset correction processing unit configured to subject the distortion compensation coefficient stored in each of the plurality of distortion compensation coefficient storage units to offset correction processing, and to generate distortion compensation coefficients in the case that the offset correction processing has not been performed, corresponding to plurality of distortion compensation coefficient storage units, in a pseudo manner and a distortion compensation processing unit configured to subject the transmission signal to the distortion compensation processing based on the distortion

Abstract: A power amplifier apparatus that includes a processor that performs a first distortion compensation processing on an input signal using a distortion compensation coefficient to obtain a first signal and an amplifier that amplifies the first signal. The processor performs a second distortion compensation processing the amplified signal using the distortion compensation coefficient to obtain a second signal and updates the distortion compensation coefficient to enable convergence between the first signal and the second signal.

Abstract: A power amplifier apparatus includes an amplifier configured to amplify an input signal converted into an analog signal, a distortion compensator circuitry configured to perform a pre-distortion process to an input signal at a second sampling rate higher than a first sampling rate at which the input signal is converted into an analog signal, a remover configured to remove a frequency component exceeding a frequency band corresponding to the first sampling rate from the input signal subjected to the pre-distortion process, a first rate converter configured to convert a sampling rate of the input signal from which the frequency component is removed from the second sampling rate to the first sampling rate, and a first signal converter configured to convert the input signal the sampling rate of which is converted into an analog signal at the first sampling rate to supply the input signal converted into the analog signal to the amplifier.