Time domain cyclic selective mapping for PAPR reduction in MIMO-OFDM systems

Peak-to-average power ratio (PAPR) is one of the main impairments in multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems. Large PAPR causes inefficiency in the power amplifier (PA) so that the energy consumption of the devices increases. Selective mapping (SLM) has been commonly used as the favorable PAPR reduction technique. Conventional SLM technique has relatively high complexity due to the use of some inverse discrete Fourier transform (IDFT) operations. In addition, it requires to transmit side information (SI) to the receiver. In this paper, we examine the performance of the low complexity time domain cyclic SLM (TD-C-SLM) in MIMO-OFDM systems. TD-C-SLM generates the signal candidates by summing the original OFDM signal and its cyclically shifted version. The signal candidate with the lowest PAPR will be transmitted. This technique requires no SI transmission. Simulation results show that up to 2 dB PAPR reduction can be achieved without increasing the out-of-band (OOB) spectrum by using the TD-C-SLM.