CCDF Curve of PAPR for SLM Method (V=4)

The Selective Mapping (SLM) method is a widely used technique for reducing the Peak-to-Average Power Ratio (PAPR) in OFDM signals, where V=4 indicates the use of 4 distinct phase sequences for selective mapping. In implementation, this typically involves generating multiple candidate signals by applying different phase rotation vectors to the original OFDM symbol before transmission, then selecting the signal with the lowest PAPR. The Complementary Cumulative Distribution Function (CCDF) curve serves as a crucial tool for evaluating PAPR performance, visually representing the probability that a signal's PAPR exceeds a given threshold. By analyzing the CCDF curve for the SLM method (V=4), we can observe the effectiveness of this approach in PAPR reduction. Through MATLAB or Python implementations, engineers typically generate multiple phase sequences using random or optimized phase factors, calculate PAPR for each candidate signal using max(abs(x).^2)/mean(abs(x).^2), and select the optimal version. As the number of phase sequences increases, the SLM technique significantly reduces the probability of high peak power occurrences, thereby optimizing overall system performance. The CCDF curve's x-axis typically represents PAPR values in dB, while the y-axis shows the probability of exceeding those values. By comparing CCDF curves of different methods, engineers can quantitatively assess SLM's optimization effectiveness through metrics like PAPR reduction gain at specific probability levels (e.g., CCDF=10^-3).