Joint Design of Transmit Waveform and Receive Filter for Dual-Function Radar Communications Based on Discrete Frequency-Coding

Dual-function radar communications (DFRC) systems have drawn considerable attention in both military and civil areas due to their potential to improve hardware and spectrum efficiency. Given the randomness of communication, DFRC waveforms are subject to variation with each transmission. Consequently, the radar receiver necessitates the complete enumeration of embedded information as a prerequisite for target echo processing, which may lead to unaffordable consumption of storage resources and force existing platforms to change their processing framework and operational timing. To address this issue, we consider a system configuration that lacks storage resources for the transmitted information and jointly design the transmit waveform and radar receive filter to achieve DFRC. Based on the discrete frequency-coding (DFC) waveform, a new coding sequence structure is designed to manipulate communication embedding and introduce the orthogonality of DFC into radar operations. The receive filter is jointly developed without requiring knowledge of communication symbols, enabling robust radar detection while preserving the system's computational efficiency. Furthermore, the proposed waveform and filter combination exhibits resistance to certain jamming techniques. Simulation results validate the effectiveness of the proposed method and demonstrate its relative superiority in terms of the trade-off between radar and communication.