摘要:
In a configuration where systems C and D having different reception quality requirements are present, a peak suppressor generates a replica of a signal from system C combined together with a signal from system D before peak suppression. Based on the replica, system specific peak suppressing units respectively perform peak suppression on signals of each system according to the respective reception quality requirements of each system. A combining unit combines the peak-suppressed signals of each system. Hence, peak suppression on signals from systems requiring different reception qualities is performed at an appropriate degree according to each system.
摘要:
A distortion compensation apparatus includes an amplifying unit, a plurality of distortion compensation coefficient storage units, a first address generating unit, a second address generating unit, and a distortion compensating unit. The amplifying unit amplifies an input signal. A plurality of distortion compensation coefficient storage units store the distortion compensation coefficients for compensating for the distortion of the amplifying unit by being associated with two different addresses. The first address generating unit generates a first address based on the current input signal. The second address generating unit generates a second address different from the first address based on the previous input signal. The distortion compensating unit obtains the distortion compensation coefficient corresponding to a combination of the first and second addresses from each of the distortion compensation coefficient storage units and performs a pre-distortion processing for the current input signal to the amplifying unit using the obtained distortion compensation coefficient.
摘要:
An amplitude suppressing apparatus includes a differential circuit that calculates a differential value of amplitude of an input signal at a point when the amplitude reaches a predetermined threshold. The amplitude suppressing apparatus also includes an amplitude suppressing circuit that suppresses the amplitude of the input signal on the basis of the differential value calculated by the differential circuit.
摘要:
A power amplifying apparatus has a bandwidth limitation process circuit to which an envelope signal included in a transmission signal is inputted, and which performs a bandwidth limitation process on the envelope signal, a variable power supply circuit for generating a power amplifier supply voltage based on a voltage control signal generated by the bandwidth limitation process circuit, and a power amplifier which is fed an input signal, and which is driven in accordance with the supply voltage from the variable power supply circuit.
摘要:
A distortion compensation apparatus for performing distortion compensation processing by applying the inverse properties of distortion properties of said 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 said distortion compensation processing, an offset correction processing unit configured to subject said distortion compensation coefficient stored in each of said plurality of distortion compensation coefficient storage units to offset correction processing, and to generate distortion compensation coefficients in the case that said offset correction processing has not been performed, corresponding to said plurality of distortion compensation coefficient storage units, in a pseudo manner and a distortion compensation processing unit configured to subject said transmission signal to said distortion compensation processing based on said distortion compensation coefficients generated in a pseudo manner.
摘要:
In a configuration where systems C and D having different reception quality requirements are present, a peak suppressor generates a replica of a signal from system C combined together with a signal from system D before peak suppression. Based on the replica, system specific peak suppressing units respectively perform peak suppression on signals of each system according to the respective reception quality requirements of each system. A combining unit combines the peak-suppressed signals of each system. Hence, peak suppression on signals from systems requiring different reception qualities is performed at an appropriate degree according to each system.
摘要:
A distortion compensating apparatus has an adaptive distortion compensating unit to compensate nonlinear distortion by controlling an input signal of a nonlinear distortion circuit by using an adaptive algorithm so as to reduce an error between a reference signal and a feedback signal from the nonlinear distortion circuit; and an adaptive equalizer connected between the adaptive distortion compensating unit and the nonlinear distortion circuit or provided in front of the adaptive distortion compensating unit. The adaptive equalizer includes a digital filter to form an amplitude characteristic and a phase characteristic of the input signal on the basis of a filter coefficient group that is set to the digital filter; a memory to hold in advance the filter coefficient group; and a control unit to control reading of the filter coefficient group from the memory on the basis of the input signal and the feedback signal.
摘要:
A power amplifying apparatus includes a high-speed low pass filter which inputs an envelope signal included in a transmission signal therein, a low-speed low pass filter which inputs the envelope signal therein, a determination unit which inputs the envelope signal therein and determines rising or falling of the envelope signal, a selecting unit which selects one of the high-speed low pass filter and the low-speed low pass filter according to a determined result of the determination unit, and a voltage supply unit which generates a voltage based on a signal input according to a selection by the selecting unit and supplies the voltage to a power amplifier which inputs the transmission signal therein so as to amplify a power of the transmission signal.
摘要:
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 compensation coefficients generated in a pseudo manner.
摘要:
A distortion compensation device which reduces a distortion of an amplifier which is added to an output signal of the amplifier, the distortion compensation device including: a plurality of distortion compensation coefficient storage circuits which stores a plurality of distortion compensation coefficients and outputs the distortion compensation coefficients according to an amplitude of an input signal of the amplifier, a distortion compensating processing circuit which adds the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to the input signal of the amplifier, and a distortion compensation coefficient updating circuit which performs weighting processing on the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to reduce the distortion compensation coefficient and which calculates an update value of the distortion compensation coefficient by using the distortion compensation coefficient which is subjected to the weighting processing.