3D-Continuous Fluid Antenna System-Enabled Index Modulation

This paper propose a novel three-dimensional continuous fluid antenna system-enabled index modulation (3D-CFAS-IM) scheme, where the fluid antenna can move continuously within a 3D region to fully exploit spatial resources. The optimal positions of the fluid antenna are determined by maximizing the minimum Euclidean distance between different receive patterns, and their indices are used to implement IM. The achievable rate, bit error rate (BER) performance, and computational complexity of the proposed scheme are analyzed. Simulation results demonstrate that the proposed scheme achieves better BER performance and a higher achievable rate compared to existing schemes, with acceptable complexity. Additionally, the impact of channel estimation errors on system performance is investigated.