Photonics-enabled joint communication-radar system with improved detection performance and looser symbol length limitation based on resampling and phase compensation

A photonics-enabled joint communication-radar (JCR) system by employing a multiple phase-shift keying (MPSK)-sliced linearly frequency-modulated (LFM) signal for simultaneous range measurement, microwave imaging, and data transmission is proposed and experimentally demonstrated with improved detection performance and looser symbol length limitation. A two-stage modulation in conjunction with optical filtering is utilized at the radar transmitter for the generation of the frequency-and-bandwidth-multiplied MPSK-sliced LFM signal while resampling and phase compensation operations are introduced at the radar receiving end to break the detection performance limitation induced by the communication symbol length when MPSK-sliced LFM signal is used. We demonstrate the concept experimentally. BPSK-sliced and QPSK-sliced LFM signals centered at 12 GHz are generated for JCR systems. When the time difference between the radar echo and the de-chirping reference is close to or greater than one symbol length, range measurement and microwave imaging that are hard to be fulfilled due to the random phase jumps of the de-chirped signal can be successfully realized via resampling and phase compensation. Experiments show that the proposed resampling and phase compensation method is valid for improving radar detection performance and loosening the communication symbol length limitation. Data communication with a data rate of up to 400 Mbps and ISAR imaging with a radar signal bandwidth of 1 GHz are successfully realized.