Orthogonal Time Frequency Space Modulation in Multiple-Antenna Systems

摘要

The application of the orthogonal time frequency space(OTFS)modulation in multiple-antenna systems is investigated.The diversity and/or the multiplexing gain can be achieved by deploying various multiple-antenna techniques,and thus the reliability and/or the spectral efficiency are improved correspondingly.We provide two classes of OTFSbased multiple-antenna approaches for both the open-loop and the closed-loop systems.Spe⁃cifically,in the open-loop system,a transmitting diversity approach,which resembles the space-time coding technique,is proposed by allocating the information symbols appropriate⁃ly in the delay-Doppler domain.In the closed-loop system,we adopt the Tomlinson-Harashi⁃ma precoding in our derived delay-Doppler equivalent transmission model.Numerical evalu⁃ations demonstrate the advantages of applying the multiple-antenna techniques to the OTFS.At last,several challenges and opportunities are presented.