Interference Suppression and Low Complexity Communication Reception for OOK-chirp Based RCC System

The existing radar-communication coexistence (RCC) waveform design based on chirp signal causes the increase of the complexity in the communication receiver, and multi-dimensional reuse also introduces more interference, leading to the deterioration of dual function performance. In this paper, a frequency division RCC system with on-off keying (OOK) based on frequency modulated continuous wave is designed for near sensors wake-up or low rate broadcast. The RCC signal has the fixed whole band and the variable sub-bands for radar signal and communication signal. We propose a two-stage envelope detection (TSED) scheme by extracting data from the frequency difference component of the two signals at the receiver without generating local radio frequency signal or using a mixer. By flexibly regulating the frequency band of two signals, the anti-interference ability of TSED can be further improved. In radar system, we perform small frequency hopping (FH) on radar signal to realize the full use of the whole band, and propose a scheme of abnormal peak detection and elimination (APDE) to eliminate the chirp interference. The simulation results show that the signal-to-interference ratio of TSED scheme for the RCC waveform can be respectively enhanced by 6 dB and 2 dB if compared with that of conventional envelope detection and coherent demodulation with a bit error rate of 10−5. Besides, The APDE scheme based on small FH reduces the range sidelobe by 20 dB and completely eliminates the added in-band interference.