Subcarrier power adjustment technique for peak-to-average power ratio reduction of OFDM systems

In this paper, we propose a novel peak-to-average power ratio (PAPR) reduction algorithm for OFDM systems that employs a two-step approach for adjusting the subcarrier power levels. The first step redistributes the power level across all subcarriers, which slightly reduces the error robustness of the system, while the second step ensures the subcarrier power distribution obeys a subband power constraint. The resulting power levels satisfy spectrum regulatory requirements across the transmission spectrum white simultaneously reducing the PAPR and maintaining a degree of error robustness. Since no overhead information is required, the proposed algorithm does not incur a throughput penalty. Simulation results for a 256-subcarrier OFDM system employing QPSK symbols and the proposed algorithm show a PAPR reduction of 1.5 dB for a complementary cumulative distribution of 0.1%.