Fluid Antenna-assisted Unsourced ISAC Massive Access
2026-06-29 • Information Theory
Information Theory
AI summaryⓘ
The authors studied a new way to improve communication in future 6G networks where many devices connect at once. They noticed that fixed antennas limit performance because they can't avoid interference well, especially when trying to send short messages. To fix this, they proposed using a flexible antenna system that can move its signal spots to find better connections and reduce errors. Their tests showed this method greatly lowers communication mistakes and improves sensing precision compared to older methods. They plan to explore this flexible antenna approach on both sending and receiving ends in future work.
Unsourced Integrated Sensing and Communication (UNISAC)6G NetworksFluid Antenna System (FAS)Finite Blocklength (FBL)Multi-user InterferencePilot CollisionAngle-of-Arrival (AOA)Probability of ErrorTime Division Multiple Access (TDMA)Spatial Diversity
Authors
Jingyuan Xu, Zhentian Zhang, Hao Jiang, Jian Dang, Zaichen Zhang
Abstract
Unsourced integrated sensing and communication (UNISAC) has emerged as a promising paradigm for supporting massive connectivity in 6G networks. However, existing approaches predominantly rely on fixed-position antennas at the base station (BS) and user equipment (UE). In uplink transmission with huge access density and limited resource budgets (i.e., finite blocklength, FBL), the fixed arrays are constrained by their physical aperture and static spatial sampling, which lead to severe multi-user interference and an unavoidable pilot collision error floor. To conquer the bottleneck derived from fixed-position physical constraint and utilize the abundant spatial diversity within compact space, this paper proposes a novel unsourced ISAC framework incorporating a fluid antenna system (FAS) at the user side. The proposed scheme exploits the positional flexibility of FAS to reconfigure the channel environment by continuously adjusting antenna ports in the spatial domain. Numerical results demonstrate that the proposed FAS-aided approach significantly reduces the per-user probability of error (PUPE) and enhances angle-of-arrival (AOA) sensing accuracy. Specifically, the proposed scheme provides a 40 dB capacity gain over traditional TDMA at 1000 active users. It should be noted that the FAS considered in this paper is only deployed at the transmitter. In our future work, we will try deploying FAS at both the transmitter and receiver.