Enabling Integrated Sensing and Communication Through Microwave Photonics

ABSTRACT Microwave photonic‐assisted integrated sensing and communication (ISAC) has attracted increasing attention in recent years. Compared with conventional electronic implementations, microwave photonics offers not only broadband signal generation and high‐frequency operation, but also wavelength‐domain reconfigurability and parallelism, low‐loss fiber distribution, true‐time‐delay beamforming, and optical‐domain preprocessing before electronic digitization. These properties make microwave photonic ISAC a promising option for future wireless systems and high‐precision sensing scenarios, such as autonomous driving, smart manufacturing, and environmental monitoring. This review provides a systematic overview of fundamental principles, performance metrics and sensing‐communication trade‐offs, and photonic architectures for signal generation, reception, and processing. Typical ISAC implementation strategies are discussed from a hardware‐signal co‐design perspective and categorized into two main classes: orthogonal resource multiplexing and fully unified‐waveform schemes. In the latter, communication signals can be directly reused for sensing, or communication information can be incorporated into radar‐oriented waveforms so that both functions are supported within the same framework. This review also summarizes enhanced ISAC schemes, specifically those incorporating coherent fusion processing algorithms or multidimensional time‐frequency multiplexing. Key challenges and emerging trends are outlined, including THz extension, higher integration, AI‐assisted optimization, multifunctional system design, and quantum‐enhanced security.