Digital pre-distortion for the linearization of power amplifiers with asymmetrical characteristics

摘要

The input signal is pre-distorted to reduce the pseudo-looking transmitting the subsequent signal amplification. Preferably of the frequency-dependent pre-distortion (frequency-dependent pre-distortion) is frequency independent predistortion (frequency-independent pre-distortion) is implemented by working in the frequency-dependent predistortion is ± 90 ° on both sides of the carrier frequency It corresponds to the amplifier distortion having a size that is proportional to the frequency offset from the phase shift and the carrier frequency. A frequency-dependent predistortion is created by differentiating the waveform corresponding to two different sets of pre-distortion parameters with respect to time. In one embodiment, one of the differential waveform is applied to the positive-frequency filter, and the other is applied to the negative frequency filter in consideration of the asymmetry of the asymmetric characteristic is generated, respectively positive and negative frequency predistortion signal. In another embodiment, only one of the differential waveform is applied to the asymmetric filters (e.g., positive or negative frequency filter of the frequency filter). ; The positive frequency filter, a frequency-dependent predistortion, phase shift, the asymmetric filter, the input signal, the pseudo transmission power amplifier