AI 中文总结
该研究针对HRLLC的短分组场景，推导失配译码下FTN系统的RCUs界，经优化功率与导频开销后FTN比奈奎斯特信号获2 dB SNR增益，凸显非渐近分析的必要性。
AI 中文摘要
本文研究超奈奎斯特（FTN）信号在超可靠低延迟通信（HRLLC）场景下的性能，重点关注短分组体制带来的挑战。传统奈奎斯特系统保持符号正交性以避免符号间干扰（ISI），而FTN则有意引入ISI以实现更高的传输速率。现有许多FTN研究假设存在完美的信道状态信息，但该假设对于关键任务型HRLLC而言往往不切实际，在此场景下，必须预留部分有限的分组长度用于导频符号以确保可靠估计。为了在短块长体制下考虑不完美信道估计的同时刻画可实现的错误概率，我们推导了FTN系统在失配译码下带参数$s$的随机编码联合界（RCUs）。数值结果表明，只要优化功率分配和导频开销，FTN相比奈奎斯特信号可提供高达2 dB的信噪比增益。这些发现凸显了非渐近分析对设计高效下一代HRLLC-FTN系统的必要性。
英文摘要
This paper investigates the performance of faster-than-Nyquist (FTN) signaling within the context of hyper-reliable low-latency communications (HRLLC), specifically focusing on the challenges imposed by the short-packet regime. While traditional Nyquist-based systems maintain symbol orthogonality to prevent inter-symbol interference (ISI), FTN intentionally introduces ISI to achieve higher transmission rates. While many existing FTN studies assume perfect channel state information, this assumption is often impractical for mission-critical HRLLC. In such scenarios, a portion of the limited packet length must be reserved for pilot symbols to ensure reliable estimation. To characterize the achievable error probability while accounting for imperfect channel estimation in the short-blocklength regime, we derive the random coding union bound with parameter $s$ (RCUs) under mismatched decoding for FTN systems. The numerical results demonstrate that FTN provides up to a 2 \dB SNR gain over Nyquist signaling, provided that power allocation and pilot overhead are optimized. These findings highlight the necessity of non-asymptotic analysis for designing efficient, next-generation HRLLC-FTN systems.
CommentsWill be presented at Globecom 2026
