Integrated sensing and communication (ISAC) has been proposed as a promising paradigm in the future wireless networks, where the spectral and hardware resources are shared to provide a considerable performance gain. It is essential to understand how sensing and communication (S\&C) influences each other to guide the practical algorithm and system design in ISAC. In this paper, we investigate the performance tradeoff between S\&C in a single-input single-output (SISO) ISAC system with finite blocklength. In particular, we present the system model and the ISAC scheme, after which the rate-error tradeoff is introduced as the performance metric. Then we derive the achievability and converse bounds for the rate-error tradeoff, determining the boundary of the joint S\&C performance. Furthermore, we develop the asymptotic analysis at large blocklength regime, where the performance tradeoff between S\&C is proved to vanish as the blocklength tends to infinity. Finally, our theoretical analysis is consolidated by simulation results.

翻译：集成感知与通信（ISAC）被提出作为未来无线网络中的一种有前景的范式，通过共享频谱和硬件资源来实现显著的性能增益。理解感知与通信（S&C）如何相互影响对于指导ISAC中的实际算法与系统设计至关重要。本文研究了有限块长下单输入单输出（SISO）ISAC系统中S&C之间的性能折衷。具体而言，我们提出了系统模型与ISAC方案，并引入速率-误差折衷作为性能指标。随后推导了速率-误差折衷的可达界与逆界，确定了联合S&C性能的边界。此外，我们开展了大步长渐进分析，证明当块长趋于无穷时，S&C之间的性能折衷趋于消失。最后，仿真结果验证了我们的理论分析。