In this paper, we perform a comparative study of common wireless communication waveforms, namely the single carrier (SC), orthogonal frequency-division multiplexing (OFDM), and orthogonal time-frequency-space (OTFS) modulation in a millimeter wave (mmWave) downlink multi-connectivity scenario, where multiple access points (APs) jointly serve a given user under imperfect time and frequency synchronization errors. For a fair comparison, all the three waveforms are evaluated using variants of common frequency domain equalization (FDE). To this end, a novel cross domain iterative detection for OTFS is proposed. The performance of the different waveforms is evaluated numerically in terms of pragmatic capacity. The numerical results show that OTFS significantly outperforms SC and OFDM at cost of reasonably increased complexity, because of the low cyclic-prefix (CP) overhead and the effectiveness of the proposed detection.

翻译：本文对毫米波下行多连接场景中常见的无线通信波形——即单载波、正交频分复用以及正交时频空调制——进行了比较研究。在该场景下，多个接入点在存在不完善的时间与频率同步误差时协同服务给定用户。为公平比较，所有三种波形均采用频域均衡的变体进行评估。为此，我们提出了一种新颖的OTFS跨域迭代检测方法。通过数值模拟以实用容量为指标评估了不同波形的性能。数值结果表明，由于循环前缀开销较低且所提检测方法有效，OTFS在复杂度合理增加的情况下显著优于单载波与OFDM。