Pseudo-Random TDM–MIMO FMCW-Based Millimeter-Wave Sensing and Communication Integration for UAV Swarm

The integrated sensing and communications (ISACs) can achieve the sharing of hardware and spectrum resources, enabling efficient data transmission and environmental sensing. This fusion is particularly important for uncrewed aerial vehicle (UAV) swarms, as it enhances the overall performance, flexibility, and efficiency of such systems. To facilitate the collaborative operations among UAVs, this article proposes an ISAC solution based on the pseudorandom time-division multiplexing (TDM)–multiple-input–multiple-output (MIMO) millimeter-wave (mmWave) frequency-modulated continuous-wave (FMCW). Specifically, a novel ISAC chirp waveform is proposed to modulate data in both the delay domain and complex amplitude, while also possessing high-precision sensing capabilities. To address challenges in the TDM–MIMO, we utilize the pseudorandom antenna selection and compressed sensing algorithms, ensuring that the maximum unambiguous velocity is not compromised. Moreover, by employing a chirp-division multiple access scheme, we propose an interference-free multiple antenna transmission scheme to achieve dynamic allocation of time–frequency resources and multiuser transmission. Finally, we propose a communication and sensing fusion-based dynamic iterative computation scheme, simultaneously achieving data demodulation and sensing parameter estimation. Simulation results show that the proposed scheme can achieve ISAC under the dynamic flight scenarios of UAVs. Meanwhile, the scheme outperforms the mmWave-LoRadar in communication and sensing performance, yet its sensing performance is slightly lower than that of the traditional FMCW. Under the urban clutter modeling, the scheme still maintains favorable robustness despite a certain degree of performance degradation.