Near-Field Magnetic Induction OAM Communications with OFDM Modulation

Magnetic induction (MI) communication in nearfield scenarios has gained much attention in recent years. From the perspective of practical applications, near-field magnetic induction (NFMI) communication limits its application in high rate demanded scenarios. In this paper, we propose the orthogonal frequency division multiplexing (OFDM) modulated orbital angular momentum (OAM)-based NFMI communication, which is called O2N communication, to increase the channel capacity where capacity limitation is a major bottleneck problem in magnetic communication systems. The O2N communication can adaptively optimize power allocation on subcarriers in association with OAM modes, significantly increasing the spectrum utilization of frequency-selective MI systems. Numerical results verify the transmission feasibility and capacity enhancement of O2N communication over multi-input multi-output (MIMO) OFDM-based magnetic communications in the near-field region. Moreover, the impact of misalignment on the O2N communication is also evaluated. High-capacity O2N communication based on the advantages of OAM and OFDM, can effectively support NFMI communication.