WSEAS Transactions on Communications
Print ISSN: 1109-2742, E-ISSN: 2224-2864
Volume 18, 2019
An Iterative Re-Weighted Least-Squares Tone Reservation Method for PAPR Reduction in OFDM Systems
Authors: , ,
Abstract: In OFDM systems, the problems associated with a high ratio of peak-to-average power still exist. A search for a simple and practical method to reduce the ratio continues. In this paper, a robust sub-optimal tone reservation method based on iterative re-weighted least-squares minimization of infinity norm is proposed. The method is simple and has a fast quadratic convergence and per iteration complexity lower than that of the FFT, where and are, respectively, the number of reserved subcarriers, and nonzero elements in the desired peak-reducing signal. In addition, the method does not experience peak re-growth problems and achieves high PAPR reductions of 3.9 dB and 5.6 dB for 1.6% and 5% reserved subcarriers respectively. For 20% reserved subcarriers, the method reaches 7.4 dB PAPR reductions. These reductions are at a small cost of 0.6 dB increase in the average transmitted power. The PAPR reductions from the proposed method compare well with the highly slow and complex optimal tone reservation methods but are far much higher than from sub-optimal methods reported in literature. Simulation results also show that the method has PAPR reductions that are linear with the binary logarithm of the number of subcarriers, and this can help to predict PAPR reductions for different OFDM systems with different number of reserved subcarriers.
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Keywords: Orthogonal Frequency Division Multiplexing (OFDM), High Power Amplifier (HPA), Peak-to-Average Power Ratio (PAPR), Iterative Re-weighted Least-Squares (IRLS), Tone Reservation (TR)
Pages: 153-161
WSEAS Transactions on Communications, ISSN / E-ISSN: 1109-2742 / 2224-2864, Volume 18, 2019, Art. #21