Sparse Channel Estimation Combined With Successive Intersymbol Interference and Power Amplifier Nonlinear Distortion Cancellation for UWB OFDM Systems

Orthogonal frequency division multiplexing (OFDM) systems commonly adopt the cyclic prefix (CP) to avoid intersymbol interference (ISI). However, the ultra-wideband (UWB) channel usually has a long duration. When considering the long-term memory effect of the power amplifier (PA), the length of CP needs to be larger than the sum of the channel length and the maximum delay of PA, degrading the system’s throughput. Aiming to mitigate the ISI and nonlinear distortions at the receiver, a sparse channel estimation combined with successive ISI and a nonlinear distortion cancellation method is proposed in this letter. Employing the derived received signal expression, channel estimation is performed using the initial pilot symbol, followed by sequential removal of ISI and nonlinear distortions to retrieve the original signal. The numerical results show that the proposed method exhibits good performance in channel estimation and original signal detection.