Judgement-based Joint SLM and PTS Algorithm for PAPR Suppression of Radar Communication Integrated System

In radar communication integrated (RCI) systems, multi-carrier shared signals based on OFDM-LFM have been widely used. However, in the OFDM-LFM-RCI multi-carrier system, there is a severe problem that the peak-to-average power ratio (PAPR) is too high. Although applying the conventional selective mapping (SLM) algorithm or partial transmit sequence (PTS) algorithm to the OFDM-LFM-RCI system can reduce the probability of high PAPR, the computational complexity of both algorithms is too high. In order to reduce the computational complexity and improve the PAPR suppression effect, a judgment-based joint SLM and PTS algorithm (J-SLM-PTS) is proposed in this paper. In the proposed J-SLM-PTS algorithm, there are two levels of PAPR suppression processing, the first is SLM algorithm and the other is PTS algorithm. Besides a judgment mechanism is introduced between the two levels. For the judgment mechanism, if the PAPR of the first level output sequence is less than the threshold PAPRth, then the sequence is directly used as the transmit sequence, otherwise it will be transferred to the second level for PTS algorithm processing. The simulation results show that the J-SLM-PTS algorithm can not only greatly reduce the computational complexity, but also have better PAPR suppression effect without reducing the communication and radar performance of OFDM-LFM-RCI systems.