Grouped-Subcarrier Based Null-Data Switching for PAPR Reduction of OFDM with Low Computational Complexity

Being a multicarrier modulation scheme, Orthogonal Frequency Division Multiplexing (OFDM) systems generally produce transmit signals with high Peak to Average Power Ratio or PAPR. Amongst numerous PAPR reduction strategies found in the literature, a relatively new but promising technique is the null and data subcarrier switching method. In this paper, we propose a new approach of null-data subcarrier switching that can achieve acceptable PAPR reduction with significantly less computational overhead. Apart from offering advantageous features like side-information less detection, distortion-free signal transmission and compatibility with other existing PAPR reduction techniques, our method also overcomes the problem of high computational requirement especially when higher number of null subcarriers are used for switching. This is achieved by applying incremental searching within preformed subcarrier groups. We demonstrate the effectiveness of our method by presenting PAPR and Bit Error Ratio (BER) related simulation results.