In this paper, we introduce a new 2D modulation scheme referred to as OTFS (Orthogonal Time Frequency & Space) that multiplexes information QAM symbols over new class of carrier waveforms that correspond to localized pulses in a signal representation called the
delay-Doppler representation. OTFS constitutes a far reaching generalization of conventional time and frequency modulations such as TDM and FDM and, from a broader perspective, it establishes a conceptual link between Radar and communication. The OTFS waveforms couple with the wireless channel in a way that directly captures the underlying physics, yielding a high-resolution delay-Doppler Radar image of the constituent reflectors. As a result, the time-frequency selective channel is converted into an invariant, separable and orthogonal interaction, where all received QAM symbols experience the same localized impairment and all the delay-Doppler diversity branches are coherently combined. The high resolution delay-Doppler separation of the reflectors enables OTFS to approach channel capacity with optimal performance-complexity tradeoff through linear scaling of spectral efficiency with the MIMO order and robustness to Doppler and multipath channel conditions. OTFS is an enabler for realizing the full promise of MUMIMO gains even in challenging 5G deployment settings where adaptation is unrealistic.
摘要表达了以下几个意思
fuse together two contradictory principles – (1) the principle of spreading (as used in CDMA) to obtain resilience to narrowband interference and to exploit channel diversity gain for increased reliability under unpredictable channel conditions and (2) the principle of orthogonality (as used in OFDM) to simplify the channel coupling for achieving higher spectral densities with a superior performance-complexity tradeoff
OTFS combines the reliability and robustness of spread spectrum with the high spectral efficiency and low complexity of narrowband transmission
OTFS in core 5G use cases eMBB: OTFS enables scaling of spectral efficiency with increased MIMO order under any channel condition with optimal performance-complexity tradeoff Internet of Things (IoT). maximizes the link budget (energy per bit) and minimizes the number of retransmissions under power and latency constraints. low PAPR and maximum available duration (to maximize link budget) while extracting full time-frequency diversity (to minimize number of retransmissions). Communication under high mobility conditions V2V or HST. maximizes throughput, reliability, and performance consistency Ultra-Reliable Low Latency Communication (URLLC). exhibits resilience to narrowband interference mm-Wave communication:explain how phase noise can be mitigated 三省少年 原创文章 263获赞 80访问量 11万+ 关注 私信 展开阅读全文