Construct Asterisk 16QAM Constellation Extension Scheme for PAPR Reduction in SC-FDMA Systems

High peak to average power ration (PAPR) leads to signal distortion and limit the high power amplifier (HPA) performance. Constellation extension scheme (CES) is an effective method to reduce the PAPR. CES generates candidate sequences by extend the constellation points and chooses one of candidate sequence with minimum PAPR as the transmitted sequence. Using Asterisk 16QAM modulation has better performance compared with Square 16QAM modulation for wireless communication channel. Therefore, this paper proposes an Asterisk 16QAM CES to improve the PAPR performance of single carrier frequency division access (SCFDMA) systems. The proposed method adopts the random selection of extend constellation points to reduce computational complexity of CES method. From the simulation results, the proposed method can effectively reduce the PAPR and has lower computational complexity character.