Photonic-assisted integrated system for communication and sensing based on time–frequency division flexibly multiplexing

The deep integration of communication and sensing technologies can provide more intelligent and customized services for more application scenarios in the fifth-generation (5G) and future sixth-generation (6G) era. In this paper, an integrated sensing and communication (ISAC) system based on time-frequency-division hybrid multiplexing (TFDM) is proposed. In this system, the TFDM signal consisting of the linear frequency modulation (LFM) signal and the orthogonal frequency division multiplexing (OFDM) signal is generated based on the inverse fast Fourier transform (IFFT). By flexibly allocating the number of carriers and time slots occupied by LFM signals and OFDM signals, the integrated system can support both communications with various data rates and radar sensing with different range resolutions. We verified the communication and sensing functions of the proposed system in W-band with the generated dynamically configurable TFDM signals through simulation. After the TFDM signal is transmitted over a 10 km optical fiber and then de-chirped and demodulated, the communication rates from 15.9 to 47.8 Gbit/s and radar ranging resolutions from 7.5 to 1.875 cm can be successfully realized.