Abstract: An apparatus comprising at least two controllers each providing control information for controlling phase or frequency of a digital signal, a combiner for combining control information from the at least two controllers to combined control information and a phase rotator for adjusting, by using phase rotation, one or more of the phase and the frequency of the digital signal on the basis of the combined control information.

Abstract: A transmission signal to be transmitted from a radio transmitter is predistorted in order to compensate for the signal distortion caused by a power amplifier. The transmission signal and a signal modeling a power supply voltage applied to the power amplifier are compared with distortion properties of the power amplifier using these signals. The distortion information is comprised in an amplitude distortion lookup table and a phase distortion lookup table. Transmission signal and power supply signal values are associated with envelope and phase predistortion information comprised in the respective lookup tables and the envelope and the phase of the transmission signal is predistorted accordingly.

Abstract: An apparatus comprising at least two controllers each providing control information for controlling phase or frequency of a digital signal, a combiner for combining control information from the at least two controllers to combined control information and a phase rotator for adjusting, by using phase rotation, one or more of the phase and the frequency of the digital signal on the basis of the combined control information.

Abstract: A transmission signal to be transmitted from a radio transmitter is predistorted in order to compensate for the signal distortion caused by a power amplifier. The transmission signal and a signal modeling a power supply voltage applied to the power amplifier are compared with distortion properties of the power amplifier using these signals. The distortion information is comprised in an amplitude distortion lookup table and a phase distortion lookup table. Transmission signal and power supply signal values are associated with envelope and phase predistortion information comprised in the respective lookup tables and the envelope and the phase of the transmission signal is predistorted accordingly.

Abstract: Disclosed is apparatus for operating with an RC filter (26, 26A), and a corresponding method. The apparatus includes circuitry (32) for use in measuring an actual value of at least one filter component and a controller (34), coupled to the measurement circuitry, for determining at least one adaptive filter (36, 46) coefficient using the measured actual value to so as to compensate for a deviation of at least one filter component value from an ideal value. Where the filter is embodied as an RC network, the circuitry measures an actual value of both a resistor and a capacitor, and the controller uses the measured actual value of the capacitor when determining the value of a resistor.

Abstract: A pulse modulator comprises a delay arrangement for receiving a first sequence of pulses and for delaying each received pulse several times to obtain a plurality of sequences of pulses having different phases. The pulse modulator further comprises a selection component for receiving from the delay arrangement a plurality of sequences of pulses having different phases, for receiving a modulating signal, wherein each possible value of the modulating signal is associated to one of the different phases, for selecting for each pulse of the first sequence of pulses a pulse of the respective sequence of pulses which sequence of pulses has a phase associated to a current value of the modulating signal, and for outputting the selected pulse as part of a pulse position modulated sequence of pulses. The invention relates equally to a modulating system comprising such a phase modulator and to a corresponding method.

Abstract: A pulse modulator comprises a delay arrangement for receiving a first sequence of pulses and for delaying each received pulse several times to obtain a plurality of sequences of pulses having different phases. The pulse modulator further comprises a selection component for receiving from the delay arrangement a plurality of sequences of pulses having different phases, for receiving a modulating signal, wherein each possible value of the modulating signal is associated to one of the different phases, for selecting for each pulse of the first sequence of pulses a pulse of the respective sequence of pulses which sequence of pulses has a phase associated to a current value of the modulating signal, and for outputting the selected pulse as part of a pulse position modulated sequence of pulses. The invention relates equally to a modulating system comprising such a phase modulator and to a corresponding method.

Abstract: Disclosed is apparatus for operating with an RC filter (26, 26A), and a corresponding method. The apparatus includes circuitry (32) for use in measuring an actual value of at least one filter component and a controller (34), coupled to the measurement circuitry, for determining at least one adaptive filter (36, 46) coefficient using the measured actual value to so as to compensate for a deviation of at least one filter component value from an ideal value. Where the filter is embodied as an RC network, the circuitry measures an actual value of both a resistor and a capacitor, and the controller uses the measured actual value of the capacitor when determining the value of a resistor.