Application of LFM-CPM signal into a DFRC system based on circulating code array

Abstract

A dual-function radar-communications (DFRC) system based on circulating code array is designed in this paper. The communication symbols are firstly embedded into the continuous phase modulation (CPM) term and then attached to the transmitted basic waveform. The particular configuration of the circulating code array provides a possibility to recover the spectrum of the transmitted basic waveform. According to the relationship between the spectrum of the synthesized signal and the spectrum of the basic waveform, a modified spatial-frequency modulation coefficient (SFMC) is proposed in the demodulation procedure. The proposed technique requires only one waveform to implement a DFRC system with an omnidirectional transmitted beam pattern. The communication function can be realized no matter that the communication direction is within the mainlobe or sidelobe of radar. It is verified that the designed DFRC system can make a balance between radar coherent processing performance and communication bit error rate (BER) performance. The communication information is secure from directions other than the intended ones. Simulation results are presented to validate the performance of the designed DFRC system.