Low complexity reconfigurable complex filters for PAPR reduction of OFDM signals: analysis, design and FPGA implementation

摘要

In this study, the authors analyse the reconfigurable filtering techniques based on the tone reservation (TR) set and data bearing subcarriers in the time domain and frequency domain to reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. The hardware architecture of these filters is proposed and mapped onto Xilinx Artix-7 field programmable gate array (FPGA) with 16-bit fixed-point representation to achieve a trade-off between numerical accuracy and hardware resource utilisation. The simulation results of the proposed methods and experimental results on FPGA for 16-quadrature amplitude modulation (QAM) and 64-QAM modulation are presented. These results show that the PAPR of OFDM signals is significantly reduced (about 7 dB) after 2-4 iterations. Performance comparison of the proposed methods with some typical methods of PAPR reduction, such as clipping-and-filtering and TR techniques, is presented.