Experimental Demonstration of Near-Field Spatial Multiplexing Using Parallel Aligned Airy Beams in Sub-THz Band

The use of high-frequency bands is key to increasing the system capacity of future wireless communication systems. Since large apertures are required to compensate for the severe path loss characteristics of high-frequency bands, near-field beam control must be considered for the efficient use of wireless resources. Airy beams, one near-field beam control technique, have asymmetric sidelobe distribution characteristics. By utilizing this characteristic, we propose creating wireless propagation areas without interference and increasing the number of transverse parallel arrangements to enhance the spatial multiplexing order. This approach will dramatically increase spectral efficiency without multiple-input multiple-output (MIMO) signal equalization. The achievement of spatial multiplexing without interference was evaluated by propagation simulations and measurements of actual transmit channel responses. Finally, we conducted data transmission experiments and achieved total transmission rates exceeding 950 Gb/s in the 150 GHz band without MIMO signal separation processing.