A Step Forward on Adaptive Iterative Clipping Approach for PAPR Reduction in OFDM System
Résumé
The Orthogonal Frequency Division Multiplexing (OFDM) is the most commonly used multicarrier modulation in telecommunication systems because of its efficient use of frequency resources and its robustness to multipath fading channels. However, as any multicarrier signal, the Peak-to-Average-Power Ratio (PAPR) is one of the major drawbacks of OFDM signals. Many research papers have dealt with the PAPR mitigation methods, such as clipping methods, tone reservation based approaches, and partial transmit signals. However, in this paper we focus on the clipping method. This method is one of the most efficient adding signal techniques for PAPR reduction in terms of complexity. Nevertheless, clipping presents many
drawbacks such as a bit error rate degradation, an out-of-band emission, and a mean power degradation. In this paper, a clipping
method featuring a threshold that adapts to the desired upper bounded output PAPR is presented. Once the desired output PAPR has been predefined, the proposed AC approach consists of clipping each OFDM symbol with an adaptive threshold so that the PAPR value of the clipped symbol is equal to this desired output PAPR. This paper proposes three different ways to compute the adaptive threshold of each OFDM symbol we want to clip according to the desired output PAPR. The theoretical analysis and the simulation results validate the interest and potential of this new clipping method.