Abstract
As one of the novel waveforms recently proposed for future 6G communications, affine frequency division multiplexing (AFDM) is capable of combating the effects of the high Doppler and achieving full diversity over high mobility wireless channels. In this paper, hybrid multi-constellations for AFDM systems are proposed. A hybrid multi-constellation is obtained by eliminating points with the largest energy and by geometric interpolation among the signal points of the traditional single constellation. Two types of hybrid multi-constellation schemes, namely multi-constellation aided AFDM-Type 1 (MC-AFDM-T1) and multi-constellation aided AFDM-Type 2 (MC-AFDM-T2), are designed to improve AFDM system reliability. Monte Carlo simulations demonstrate that the proposed MC-AFDM-T1 and MC-AFDMT2 schemes are capable of achieving better symbol error rate (SER) compared to that of the original-AFDM (Ori-AFDM).