A combined technique for carrier frequency offset estimation and peak-to-average power ratio reduction in OFDM systems using null subcarriers and Cuckoo search algorithm

This paper presents a novel generic method for the carrier frequency offset (CFO) estimation and reduction of peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing based wireless communication systems. Estimation of CFO using null subcarriers embedded in one or more pilot symbol is one of the best known CFO estimation techniques that achieve an estimation range of inverse of the sampling interval with low implementation complexity. We propose to exploit a few null subcarriers in the pilot symbol for PAPR reduction by switching with some data subcarriers in the data block of which the PAPR is intended to be minimized. We define a new cost function for the PAPR reduction at the transmitter and CFO estimation at the receiver and the computational complexity of its evaluation is made significantly low by applying Cuckoo search optimization algorithm. Also, the proposed method requires less side information to be send to the receiver as compared to many of the prevailing PAPR reduction methods. Computer simulation studies reveal that the proposed combined technique offers significant performance advantage for both PAPR reduction and CFO estimation concurrently.