摘要:
A wireless apparatus includes: an A/D converter which samples an in-phase signal component and a quadrature signal component from a quadrature-modulated signal of analog form alternately; a digital quadrature demodulation unit which applies digital quadrature demodulation to an output signal of the A/D converter and outputs an in-phase signal and a quadrature signal; and an error detection unit which, based on the in-phase and quadrature signals output from the digital quadrature demodulation unit, detects a time difference error between the sample timing of the in-phase signal component and the sample timing of the quadrature signal component.
摘要:
A wireless apparatus includes: an A/D converter which samples an in-phase signal component and a quadrature signal component from a quadrature-modulated signal of analog form alternately; a digital quadrature demodulation unit which applies digital quadrature demodulation to an output signal of the A/D converter and outputs an in-phase signal and a quadrature signal; and an error detection unit which, based on the in-phase and quadrature signals output from the digital quadrature demodulation unit, detects a time difference error between the sample timing of the in-phase signal component and the sample timing of the quadrature signal component.
摘要:
A distortion compensating apparatus includes a processing circuit that calculates each of a plurality of series operation coefficient pairs based on a transmission signal and a feedback signal of an output from an amplifying circuit performing power amplification of the transmission signal, executes a series operation process with respect to the transmission signal based on the plurality of the series operation coefficient pairs as a distortion compensation of the transmission signal, and inputs a result of the series operation process to the amplifying circuit performing the power amplification, and a selecting unit that, on the basis of power of the transmission signal, selects the series operation process to be executed corresponding to one of the plurality of series operation coefficient pairs, or selects one of the plurality of series operation coefficient pairs to be used in the series operation process to be executed.
摘要:
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.
摘要:
A distortion compensation apparatus includes a distortion compensation signal generation unit that performs, on a transmission signal, distortion compensation processing using a series operation; a coefficient updating unit that updates series operation coefficients used for the series operation based on a feedback signal of a power amplification output which is output through power amplification processing of a distortion compensation signal output from the distortion compensation signal generation unit, and based on the distortion compensation signal; a memory that stores the distortion compensation signal corresponding to a transmission signal having a given power value and the feedback signal of the power amplification output as restraint information; and a control unit that performs control so that, in accordance with the power value of the transmission signal, restraint information corresponding to a power value different from the power value of the transmission signal is read and used for updating the series operation coefficients.
摘要:
An apparatus includes: a unit that stores the look-up table including distortion compensation coefficients; a unit that selects addresses according to an input signal, acquires coefficients stored at the selected addresses, and performs the predistortion of the input signal by using the acquired coefficients; a unit that calculates an error signal by comparing with the input signal a feedback signal that indicates an output of a power amplifier to which a result of the predistortion is inputted; a unit that calculates coefficients from the error signal and the acquired coefficients by using the adaptive algorithm; a unit that, for each of the selected addresses, selects coefficients as adequate coefficients from among the calculated coefficients according to the error signal; and a unit that, for each of the selected addresses, calculates an average value of the adequate coefficients and replaces a stored coefficient in the look-up table with the average value.
摘要:
A peak suppressing and restoring method includes suppressing a peak of a signal, starting suppression when a suppression start value is lower than a suppression target value, using a function of a gain characteristic such that a peak amplitude value attains the suppression target value, and restoring the suppressed peak of the signal using an inverse function of the function of the gain characteristic.
摘要:
A distortion compensation apparatus includes a distortion compensation unit that performs distortion compensation processing on a transmission signal by a series operation, a coefficient update unit that updates a group of series operation coefficients used for the series operation based on a feedback signal of transmission signal output that is output after power amplification processing is performed on output of the distortion compensation unit and the transmission signal, an initial coefficient memory that stores the groups of series operation coefficients that become initial values for coefficient update processing by the coefficient update unit, and a power fluctuation detection unit that detects a power fluctuation of the transmission signal and, when the power fluctuation is detected, reads the groups of series operation coefficients from the initial coefficient memory and provides the groups of series operation coefficients to the coefficient update unit.
摘要:
A distortion correction control apparatus is for compensating for a burst distortion of a transmission amplifier caused by a burst of an input signal of a transmission target. The apparatus includes a generation unit that generates a distortion correction coefficient having reverse characteristics to the foregoing burst distortion; a unit that multiplies the distortion correction coefficient output from the generation unit by the input signal or adds the distortion correction coefficient output from the generation unit to the input signal, upon reception of burst information notifying of switching between presence and absence of the input signal; and an update unit that updates, based on the input signal and a branch signal fed back as an output signal of the transmission amplifier, parameters of functions used for adaptively generating the distortion correction coefficient, and that inputs the updated parameters to the generation unit.
摘要:
A distortion correction control apparatus is for compensating for a burst distortion in a transmission amplifier caused by a burst of an input signal of a transmission target. The apparatus includes a holding unit that stores a distortion correction coefficient having reverse characteristics to the burst distortion; a unit that multiplies the distortion correction coefficient read out from the holding unit by the input signal or adds the distortion correction coefficient read out from the holding unit to the input signal, upon reception of burst information notifying of switching between presence and absence of the input signal; and an update unit that updates, based on the input signal, the distortion correction coefficient of the last time, and a signal fed back as an output signal of the transmission amplifier, the distortion correction coefficient by an adaptive algorithm, and that inputs the updated distortion correction coefficient to the holding unit.