Flexible Waveform Design for RO-ISAC Based on OFDM-Embedded Maximum Length Sequence

Retroreflective optical integrated sensing and communication (RO-ISAC) has revealed great potential lately, due to its advantages of enhanced light reflection, large transmission capacity and high sensing accuracy. Since the overall performance of RO-ISAC systems largely depends on the integrated waveform design, in this Letter, we propose a flexible waveform design based on orthogonal frequency division multiplexing-embedded maximum length sequence (OFDM-MLS) for RO-ISAC systems. The proposed OFDM-MLS waveform can benefit from both the superior sensing performance of MLS and the excellent communication performance of OFDM. Furthermore, flexible communication and sensing performance trade-off can be efficiently achieved by adaptively adjusting the power allocation ratio between the MLS signal and the OFDM signal in the flexible OFDM-MLS waveform design. Experimental results successfully verify the feasibility and superiority of the proposed OFDM-MLS waveform in RO-ISAC systems.