Abstract: A peak suppression device includes an acquiring unit that acquires multiple envelopes of carrier signals that are included in a multicarrier signal, an adding unit that adds the envelopes to generate a combined envelope, a detecting unit that detects a peak value and a peak timing of the multicarrier signal by using the combined envelope, and a suppressing unit that suppresses a peak of the multicarrier signal in accordance with the peak value and the peak timing.

Abstract: A distortion compensation device includes a multiplier, a subtracter, an LUT, and a distortion compensation unit. The multiplier calculates the product of amplitudes or the product of power of transmission signals at two different times or calculates the ratio of amplitudes or the ratio of power of transmission signals at two different times. The subtracter calculates the phase difference between the transmission signals at two different times. The LUT specifies a distortion compensation coefficient by using both the product or the ratio calculated by the multiplier and the phase difference calculated by the subtracter. The distortion compensation unit performs, by using the distortion compensation coefficient specified by the LUT, a predistortion process on the transmission signal that is input to the amplifier.

Abstract: A peak suppression device includes a suppression-signal generating unit and a band pass filter (BPF). The suppression-signal generating unit generates a suppression signal that is obtained by adding, to a transmission signal, a frequency component in which components of frequencies from a boundary of a band of the transmission signal to a frequency that is away therefrom toward an out-band of the transmission signal by predetermined frequencies are attenuated, out of frequency components of a signal to suppress a peak of the transmission signal. The BPF attenuates, after the suppression signal is amplified by the amplifier, a frequency component outside the band of the transmission signal in the amplified suppression signal.

Abstract: A distortion compensation device includes a multiplier, a subtracter, an LUT, and a distortion compensation unit. The multiplier calculates the product of amplitudes or the product of power of transmission signals at two different times or calculates the ratio of amplitudes or the ratio of power of transmission signals at two different times. The subtracter calculates the phase difference between the transmission signals at two different times. The LUT specifies a distortion compensation coefficient by using both the product or the ratio calculated by the multiplier and the phase difference calculated by the subtracter. The distortion compensation unit performs, by using the distortion compensation coefficient specified by the LUT, a predistortion process on the transmission signal that is input to the amplifier.

Abstract: A distortion compensation device includes an address generating unit, an LUT, and a multiplier. The address generating unit calculates the magnitude of a first vector and the angle formed by the first vector and a second vector. The first vector is represented by using the origin in an IQ coordinate plane as the starting point and using a transmission signal point at a first time as the end point. The second vector is represented by using a transmission signal point at a second time that is predetermined time before the first time as the starting point and using the transmission signal point at the first time as the end point. The LUT specifies a distortion compensation coefficient by using the calculated magnitude and the calculated angle. The multiplier performs a predistortion process on a transmission signal input to an amplifier by using the specified distortion compensation coefficient.

Abstract: A distortion compensation device includes an address generating unit, a look up table (LUT), and a multiplier. The address generating unit calculates pieces of difference information for different combinations each including transmission signals at different timings. Each of the pieces of difference information is the difference in amplitude or power between the transmission signals in a corresponding one of the combinations. The LUT specifies a distortion compensation coefficient by using the above pieces of difference information calculated by the address generating unit. The multiplier performs predistortion, using a distortion compensation coefficient specified by the LUT, on a transmission signal to be input to an amplifier.

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 including: a memory configured to store a plurality of distortion compensation coefficients for compensating distortion to an input signal amplified by an amplifier, each of the plurality of distortion compensation coefficients being associated with a different combination of two addresses, and a processor configured to receive temperature information associated with a temperature of the amplifier, generate a first address based on the input signal at a first time, generate a second address based on an average of the input signal during a previous period preceding the first time, the average being calculated based on the temperature information, select a distortion compensation coefficient from the plurality of distortion compensation coefficients based on the first address and the second address, and compensate distortion to the input signal based on the selected distortion compensation coefficient.

Abstract: A peak suppression apparatus includes an acquiring unit that acquires a first signal represented by an amplitude waveform of a multicarrier signal, a generator that generates a second signal represented by a waveform sequentially connecting a plurality of peak points adjacent to one another in the first signal as a peak detection signal for the multicarrier signal, a detector that detects a peak value and a peak timing of the multicarrier signal by using the peak detection signal, and a suppressing unit that suppresses a peak of the multicarrier signal based on the peak value and the peak timing.

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 peak suppression device includes a suppression-signal generating unit and a band pass filter (BPF). The suppression-signal generating unit generates a suppression signal that is obtained by adding, to a transmission signal, a frequency component in which components of frequencies from a boundary of a band of the transmission signal to a frequency that is away therefrom toward an out-band of the transmission signal by predetermined frequencies are attenuated, out of frequency components of a signal to suppress a peak of the transmission signal. The BPF attenuates, after the suppression signal is amplified by the amplifier, a frequency component outside the band of the transmission signal in the amplified suppression signal.

Abstract: A distortion compensation device includes: a storage configured to store a distortion compensation coefficient for compensating a distortion of a transmission signal to be amplified and transmitted, by corresponding to a combination of a plurality of addresses; a first generator configured to generate a first address according to a power or an amplitude of an input signal; a second generator configured to generate a second address according to a first vector to interconnect sample points on an IQ plane where the sample points of the input signal are drawn in time series; and a distortion compensation unit configured to acquire the distortion compensation coefficient corresponding to a combination of the first address and the second address from the storage, and to perform a predistortion processing on the input signal, by using the acquired distortion compensation coefficient, so as to generate the transmission signal.

Abstract: A peak suppression device includes an acquiring unit that acquires multiple envelopes of carrier signals that are included in a multicarrier signal, an adding unit that adds the envelopes to generate a combined envelope, a detecting unit that detects a peak value and a peak timing of the multicarrier signal by using the combined envelope, and a suppressing unit that suppresses a peak of the multicarrier signal in accordance with the peak value and the peak timing.

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 which compensates for a distortion of an amplifier includes an FIR filter, a calculation unit that calculates an error between a reference signal and a feedback signal from the amplifier, an update unit that updates a coefficient set to the FIR filter on the basis of the error, and a delay unit that, on the basis of a magnitude of the coefficient, delays the feedback signal while controlling a delay of the feedback signal with respect to the reference signal.

Abstract: A distortion compensation apparatus including: a processor configured to generate a pre-distortion signal by compensating an input signal for a distortion based on a distortion compensation coefficient and a plurality of delayed signals obtained by delaying the input signal by a plurality of amounts of delay, and an amplifier configured to generate an amplified signal by amplifying the pre-distortion signal, wherein the processor calculates the distortion compensation coefficient based on the input signal, the pre-distortion signal, and the amplified signal, and calculates the plurality of amounts of delay based on the amplified signal.

Abstract: A peak suppression apparatus includes an acquiring unit that acquires a first signal represented by an amplitude waveform of a multicarrier signal, a generator that generates a second signal represented by a waveform sequentially connecting a plurality of peak points adjacent to one another in the first signal as a peak detection signal for the multicarrier signal, a detector that detects a peak value and a peak timing of the multicarrier signal by using the peak detection signal, and a suppressing unit that suppresses a peak of the multicarrier signal based on the peak value and the peak timing.