Joint adaptive modulation and predistortion for nonlinear time-varying channels

This paper proposes a simple joint adaptive modulation and predistortion scheme over nonlinear time-varying channels equipped with High Power Amplifiers (HPAs). The paper includes the probability of Bit Error Rate (BER) analysis of MQAM transmission over nonlinear channels, which is the key factor in designing adaptive modulation. The paper includes performance comparison of adaptive modulation over nonlinear channels with and without predistortion, for different normalized Doppler frequencies. The analysis is supported with simulation results. Results show that the combined adaptive modulation with predistortion technique significantly improves the spectral efficiency.