Optical Wireless Integrated Sensing and Communication Based on Frequency Modulated Waveform Encoding and MIMO Technology

Abstract

Integrated sensing and communication (ISAC) is a crucial technology in the future sixth-generation (6G) mobile communication network. Radio frequency (RF)-ISAC has been a major focus in recent years, but optical wireless (OW)-ISAC has also attracted significant attention due to its potential benefits, which include the enhancement of communication rates, the improvement of sensing precision, and the reduction of interference. In this article, we propose an OW-ISAC framework combining arbitrary waveform frequency modulated continuous wave (AW-FMCW) sensing and communication technology and multi-input multi-output (MIMO) technology. Leveraging the arbitrary waveform capability of AW-FMCW technology, joint sensing and communication design are achieved through frequency-modulated waveform encoding. MIMO technology, widely adopted by RF-ISAC, is being applied for the first time in OW-ISAC to achieve high-precision estimation of direction of arrival (DOA). At the transmitter end, the multi-beam property of optical phase array (OPA) is utilized for multi-target communication and sensing tasks. At the receiver end, a well-designed uniform linear photodiode (PD) array is employed to extract echo signals from a specific direction while eliminating interference from other signals. Furthermore, the decoding matrices and PD orientations are optimized to achieve adaptive directional sensing. Finally, extension numerical simulations are conducted to validate the performance of multi-channel integrated sensing and communication capabilities.