Autoencoder-Based Enhanced Joint Delay-Doppler Index Modulation for OTFS Modulation

Orthogonal time frequency space (OTFS) provides highly effective performance in channels that exhibit both time and frequency variability. OTFS can fully leverage channel diversity by multiplexing data symbols on the whole delay-Doppler domain. However, improving the reliability of OTFS systems is essential to meet the rigid requirements of next-generation communication technologies. Addressing these challenges, we introduce a novel approach named autoencoder (AE)based enhanced joint delay-Doppler index modulation OTFS (AEE-JDDIM-OTFS). This strategy selectively activates either delay or Doppler resource bins within a subframe, utilizing multidimensional symbol vectors created by the AE to boost error performance. The capability of AE to generate symbols with increased squared minimum Euclidean distance (SMED) plays a crucial role in this enhancement. Computer simulation outcomes confirm that AEE-JDDIM-OTFS surpasses traditional OTFS and other comparative schemes in bit error rate performance.