基于OFDM的双基地ISAC空口同步：系统概念与性能分析
Bistatic OFDM-based ISAC with Over-the-Air Synchronization: System Concept and Performance Analysis
AI总结：
针对双基地ISAC收发同步难题，本文提出基于前导码与导频空口同步的OFDM信号处理框架，比较导频子载波和完整OFDM帧两种雷达处理方式，并通过误差影响分析与概念验证测量评估性能。
AI中文摘要：
集成感知与通信（ISAC）已被定义为6G移动通信系统的目标之一。在此背景下，本文介绍了一种基于正交频分复用（OFDM）的双基地ISAC系统。尽管与单基地架构相比，双基地架构具有不要求全双工运行等优势，但也带来了发射机与接收机同步的需求。为此，本文提出一种双基地ISAC信号处理框架：入射的基于OFDM的ISAC信号先基于前导码符号和导频进行空口同步，随后执行双基地雷达处理，处理时可仅使用导频子载波，也可使用完整OFDM帧。后一种方法需要基于通信处理估计原始发射帧，因而要求无差错通信，这可通过适当的信道编码实现。通过分析残余同步失配和数据解码失败对通信与雷达性能的影响，本文评估了上述两种方法下所提系统的性能与局限。最后，概念验证测量结果验证了所进行的分析。
英文摘要：
Integrated sensing and communication (ISAC) has been defined as one goal for 6G mobile communication systems. In this context, this article introduces a bistatic ISAC system based on orthogonal frequency-division multiplexing (OFDM). While the bistatic architecture brings advantages such as not demanding full duplex operation with respect to the monostatic one, the need for synchronizing transmitter and receiver is imposed. In this context, this article introuces a bistatic ISAC signal processing framework where an incoming OFDM-based ISAC signal undergoes over-the-air synchronization based on preamble symbols and pilots. Afterwards, bistatic radar processing is performed using either only pilot subcarriers or the full OFDM frame. The latter approach requires estimation of the originally transmitted frame based on communication processing and therefore error-free communication, which can be achieved via appropriate channel coding. The performance and limitations of the introduced system based on both aforementioned approaches are assessed via an analysis of the impact of residual synchronization mismatches and data decoding failures on both communication and radar performances. Finally, the performed analyses are validated by proof-of-concept measurement results.
