Cognitive Transmit Subarray FDA Design for Integrated Radar-Communication Using Flexible Sidelobe Control

This paper presents cognitive overlapped-frequency diverse array (FDA) for joint radar-communications to achieve improved performance for moving radar target and communica- tion receiver(s). In this scheme, the FDA transmit array is divided into two subarrays and each subarray coherently transmits an orthogonal waveform with different frequency increments. In addition, we consider the time variant in FDA, which is usually ignored in the literature. Further, we propose Chebyshev window function to design two transmit weights matrices to achieve distinct sidelobe levels (SLLs) for communication operation but the same mainlobe for radar functionality. The communication information message is embedded into the orthogonal waveforms via the sidelobe control during each radar pulse. By using the cognitive closed-loop method, we can update the parameters in real time to improve moving target and communication receiver(s) tracking performance. Moreover, the information bits can be efficiently detected by the intended receiver due to equal magnitude in the SLLs. The effectiveness of the proposed scheme is verified by simulation results.