Compensation of oscillator frequency pulling

摘要

A transmitter includes an amplitude modulation path, and a frequency modulation path including a phase locked loop (PLL) having a controllable oscillator and a phase detector. The transmitter further includes an amplitude to frequency distortion compensation unit configured to generate a compensation signal based on amplitude data from the amplitude modulation path, error data based on an output of the phase detector, and data reflecting a transfer function from the controllable oscillator to the output of the phase detector, and is further configured to provide the compensation signal to a node in a feedforward path of the PLL.

主权项

1. A transmitter, comprising:
an amplitude modulation path; a frequency modulation path including a phase locked loop (PLL) comprising a controllable oscillator and a phase detector; and an amplitude to frequency distortion compensation unit configured to generate a compensation signal based on amplitude data from the amplitude modulation path, and error data based on an output of the phase detector, and wherein the amplitude data is filtered by a transfer function that models a transfer function from the controllable oscillator to an output of the phase detector, and further configured to provide the compensation signal to a node in a feedforward path of the PLL, wherein the amplitude to distortion compensation unit is configured to generate the compensation signal using a training sequence before an actual packet transmission by the transmitter.