Affine Frequency Division Multiplexing (AFDM) is recognized as a viable waveform for the upcoming generation of high-speed wireless communications due to its resilience against doubly selective channels. However, high PAPR in conventional AFDM systems results in reduced power amplifier efficiency and deteriorates transmission performance overall. In this paper, the application of transform domain precoding techniques such as Walsh-Hadamard Transform (WHT) and Modulated Lapped Transform (MLT) for AFDM systems is investigated to solve this problem. The proposed AFDM-MLT scheme spreads information symbols over the transmission frame, which leads to the improved signal energy distribution and the reduced amplitude fluctuations. The proposed method is evaluated in MATLAB simulations. The simulation results demonstrate that AFDM-MLT achieves a better BER performance compared to the conventional AFDM, and a significant PAPR reduction with low computational com plexity. Furthermore, the proposed scheme is better in overall communication reliability and power efficiency. The results show that MLT precoding is a feasible technique for improving AFDM systems and it is a promising candidate for future high mobility wireless communication networks.

Affine Frequency Division Multiplexing (AFDM), Modulated Lapped Transform (MLT), Peak-to Average Power Ratio (PAPR), Bit Error Rate (BER), Doubly Selective Channels, Delay-Doppler Communications.