A Multi-Objective Optimization-Based Approach to Waveform Design in JCAS Systems

Joint Communication and Sensing (JCAS) integrates communication and sensing (C&S) functions into a single system by sharing the same transmit signal. This paper focuses on a radar-centric JCAS system that transmits probing signals to detect targets while delivering communication data to users on the downlink. We aim to design a joint waveform that achieves three objectives: minimizing the mismatch between the desired and actual JCAS beam patterns, reducing multi-user interference (MUI), and adhering to per-antenna power constraints. We propose a waveform design based on multiobjective optimization to address the challenges associated with waveform design, highlighting the trade-offs between sensing and communication performance. To establish a balance between C&S performance, we introduce a trade-off control parameter. Initially, we reformulate the waveform design problem as an unconstrained problem and then present a new low-complexity waveform synthesis algorithm using gradient descent (GD). Finally, numerical results demonstrate the impact of the trade-off control parameter and demonstrate the effectiveness of our proposed algorithm compared to state-of-the-art techniques, ensuring optimal performance for both C&S in JCAS systems.