Analysis of decision aided channel estimation in clipped OFDM

Transmit signals in orthogonal frequency-division multiplexing systems exhibit a property of high peak-to-average power ratio (PAPR). Digital clipping is a popular and simple method to overcome large PAPR, but it results in a nonlinear distortion, which degrades the performance of channel estima- tion. In this paper, the clipping effect on channel estimation is analyzed firstly, then a decision-aided channel estimation method to mitigate the clipping distortion is developed and its potential gain in channel estimation is derived theoretically. In clipped OFDM, the potential gain can be obtained by iterative channel estimation and signal detection. Simulation results show that the decision aided method can effectively improve the performance of channel estimation and the theoretical gains match the simulation results well. I. INTRODUCTION