High Quality OFDM Communication System Based on Carrier Interferometry and Digital Linearization of HPA

For this nonlinear compensation, we address the PAPR reduction method and linearization of HPA at the same time. High quality OFDM communication system is our goal, which can be possible to use the carrier interferometry in the OFDM system and to digitally linearize the nonlinear HPA. The first method is a CI/OFDM (carrier interferometry OFDM) for PAPR reduction of the OFDM signal and the second is the predistortion of HPA for the linearization. In this paper, CI/OFDM system is implemented in the DSP board and RF communication board. Also, polynomial-based predistorter is used for the linearization of the HPA. The CI/OFDM uses full frequency diversity and is robust to the narrow band interference. CI/OFDM lowers down the high PAPR and we can compensate the HPA non-linear distortion by digital predistorter. It is shown that the designed CI/OFDM system has better BER performance and higher power efficiency than the ordinary OFDM system.