HPA linearization technique of cascading PAPR reduction and predistortion

The inherent high peak to average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems is extremely sensitive to nonlinear distortion, and significantly reduces the efficiency of high power amplifier (HPA). To resolve this problem, a combined predistortion and PAPR reduction scheme is proposed in this paper. The predistorter can no longer compensate HPA´s nonlinearity when input signal´s magnitude exceeds the linear region. In such circumstance, PAPR reduction technique preventing signals from falling into saturated region is valuable. Based on Rapp model, simulation results and theoretical analysis show that the cascade of predistortion and PAPR reduction technique results in a larger shoulder level and enhancement of power efficiency.