A Sparse Channel Estimation Scheme Combined With Distorted Signal Detection for UWB OFDM Systems

Nonlinear distortions generated by the power amplifier (PA) will affect the performance of channel estimation thus the veracity of signal detection for ultra-wideband (UWB) orthogonal frequency-division multiplexing (OFDM) systems. The existing nonlinear cancellation techniques for tackling this problem reduce the overhead of the system due to the large number of pilot subcarriers required. As the UWB channel can usually be modeled as sparse, an iterative method that estimates the sparse channel and recovers the original signal, referred to as SCE-DSD, is proposed in this letter. Involving the nonlinear distortion in the measurement matrix construction, SCE-DSD estimates the channel and the original signal sequentially. The numerical results show that, compared to the state-of-the-art method, the proposed method has a better performance using a smaller number of pilot subcarriers.