Sequential Search Method with Different Thresholds for Clipped Power for OFDM Signal

To address the problem of a large peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) signaling, which mitigates the detrimental effects caused by a multi-path environment, we propose a sequential search method that employs different thresholds for clipped power for a partial transmit sequence (PTS) algorithm and/or cyclically shifting PTS algorithm. The proposed method can effectively select the weighting factors for the phase rotation and/or cyclically shifting point with a lower level of complexity, and can mitigate the degradation in the error rate performance due to the non-linearity of the transmitter amplifier by applying different threshold values for the clipped power. In addition, we present a method that can mitigate the performance degradation especially for spatial division multiplexing (SDM)-OFDM. Furthermore, we introduce a transmission method of the weighting factor for the phase rotation or the cyclically shifting point by using channel-estimation pilot symbols. Subsequently, there is no need for extra control channels, which result in a loss in the transmission efficiency