DSP oriented implementation of a feedforward power amplifier linearizer

In this contribution we introduce a new digital signal processing (DSP)-oriented implementation of a feedforward linearizer. The intermodulation distortion (IMD) signal is regenerated entirely in the digital baseband which gives better control over the linearization process and also improves the efficiency of the overall amplifier. A new scheme to estimate the parameters of the proposed feedforward linearizer is presented which decouples the parameters of the signal and error cancellation loop. We have verified the new DSP oriented feedforward linearizer by means of simulations in the presence of component impairments like, e.g., IQ mismatch. Initial measurements results in a laboratory setup show a reduction of the adjacent channel power of approximately 15 to 20 dB.