A Variable Damping Factor Based Message Passing Detector for AFDM

Many new modulation technologies have been proposed to solve the problem of unreliable communication in high-speed mobile scenarios. Affine frequency division multiplexing (AFDM) has been widely studied due to its low pilot overhead. However, the research on AFDM detection algorithms remains limited. When employing existing message-passing (MP) algorithms for signal detection, using fixed damping factors in these algorithms often results in a trade-off between bit error ratio (BER) performance and the number of iterations. To overcome these limitations, this paper proposes a variable damping factor based message passing (VD-MP) algorithm. The VD-MP algorithm dynamically selects the optimal damping factor based on different channel conditions to achieve superior performance. We have demonstrated through simulation experiments that the VD-MP algorithm indeed has better BER performance than the traditional MP algorithm.