A combined PAPR reduction and predistorter scheme for Osstems in nonlinear channels

Orthogonal frequency division multiplexing system is known to be sensitive to nonlinear distortion due to its high peak-to-average power ratio (PAPR). Without proper linearization techniques, power efficiency is often compromised to control the nonlinear distortion caused by power amplifiers. The nonlinear distortion caused by a power amplifier is due to clipping distortion and compressive gain distortion. A combined PAPR reduction and predistorter (PD) scheme is proposed to efficiently mitigate both these distortion components. Simulation results show that the combined scheme results in an adjacent channel power ratio improvement which is twice as good as that achieved by the PD. The observed gain in the system total degradation equals the sum of the improvements provided by each method separately. These results reflect the effectiveness of the combined scheme in combating nonlinear distortion as well as improving power efficiency