Two proposed approaches for minimization of both sidelobe and PAPR in Cognitive Radio network

Cognitive Radio (CR) is considered an important solution for the spectrum scarcity problem. Orthogonal Frequency Division Multiplexing (OFDM) based cognitive radio system, i. e. Non-Contiguous (NC) OFDM system used as modulation scheme. NC-OFDM has two main problems, high Peak to Average Power Ratio (PAPR) and high sidelobe power, which cause interference with Primary Users (PUs). Many solutions were proposed to solve these problems. In this paper, two techniques to reduce both PAPR and sidelobe are proposed. Instead of usingSelective Mapping (SLM) with Multiple Choice Sequences(MCS) alone, first proposed technique suggests adding extra interleaver on the input data to achieve more reduction on PAPR. The second proposed technique is based on the phase shift adjustment in SLM. Simulation results show that the two proposed techniques improve both the PAPR and Sidelobe power. The proposed technique with adding interleaver is more complex than the phase shift adjustment technique.