Concurrent Sensing and Communications Based on Intelligent Metasurfaces

ABSTRACT Intelligent metasurface (IM), a kind of ultrathin engineered structure composed of real‐time controllable elements, has gained intensive attention in the areas of wireless communications and sensing over the past decade, owing to its unique capability of artificial intelligence (AI) empowered electromagnetic (EM) beam manipulation. Yet, it remains an open challenge in developing integrated sensing and communications (ISAC) scheme with the lower consumption of energy and frequency spectrum, the lower hardware cost, the better information security, etc. Here, we propose an IM‐assisted concurrent ISAC (C‐ISAC in short) scheme in the context of the direct antenna modulation (DAM) by sharing selectively a set of IM coding patterns for the concurrent 16‐amplitude‐phase‐shift‐keying (16‐APSK) communications and sensing (human gesture recognition here). Moreover, the residual energies associated with low‐power DAM symbols, that is traditionally wasted in conventional DAM communications, have been recycled for the purpose of wireless sensing in our approach, leading to the reuse of hardware and energy for ISAC. Thereby, this design is capable of not only addressing the issue of energy inefficiency involved in conventional DAM communications, but also enabling the simultaneous symbol‐level signal transmission and sensing. We have implemented a prototype using a 1‐bit phase‐quantized IM, and experimentally demonstrated its superior ISAC's performance in terms of energy efficiency consistent with theoretical predictions. The presented method shows great potential for applications in smart homes, low‐altitude economy, intelligent transportation, smart factories, and robotics.