Low PAPR OFDM with implicit side information and reduced complexity for IOT networks

摘要

In this paper, we present a new technique of reducing PAPR for OFDM transmission to meet the increasing demand of an efficient OFDM realization for IOT networks. PAPR reduction is based on code multiplication with several circular shifts of the input mapped vector and the selected vector is the one with minimum PAPR. Compared to the selected mapping (SLM), only one code is required, iteration process is done via circular shift of input vector, and side information is implicit in the data vector. Pilot SCs with carefully selected indexes are inserted to the data vectors for implicit determination of circular shifts and channel estimation at the receiver. We also present a low-complexity implementation algorithm for OFDM baseband transmitters, in which no complex multiplication is required at all. PAPR of 5.5-6.5dB per 10000 OFDM symbols is achieved for 16-QAM and 64-QAM with limited loss of power and bandwidth. Besides, no error in the extraction of the side information is detected at the receiver assuming frequency selective fading channel with {5, 70, 140} Hz Doppler shifts and up to 5 MHz OFDM bandwidth.