Novel Leakage-Based Capacity Enhancement Scheme for Multi-User OAM Communications

This paper explores a novel leakage-based capacity enhancement scheme in an orbital angular momentum (OAM) integrated multiuser MIMO system, where the leakage refers to the signal interference affecting other users. We aim to optimize a precoder using signal-to-leakage-and-noise ratio (SLNR) to maximize capacity and minimize interference and noise. For OAM modes generated using a uniform circular array, the proposed SLNR is compared with regularized zero-forcing (RZF), block-diagonalization (BD), and zero-forcing (ZF) precodings applied in indoor multiuser OAM-MIMO systems. Simulation results show that the SLNR-based multiuser OAM-MIMO outperforms the traditional multiuser MIMO, RZF, BD, and ZF-based multiuser OAM-MIMO in the context of capacity.