Capacity Improvement in Reconfigurable Intelligent Surface Assisted MIMO Communications

Reconfigurable intelligent surface (RIS) is thought to be a potential key technique for future wireless communications due its ability manipulating the electromagnetic environment smartly. This paper focuses on rank and capacity analysis when RIS introduced into multiple-input multiple-output (MIMO) system. By establishing system model this communication system, various simulations are conducted identifying characteristics of channel. The different distance between access point (AP) user equipment (UE) show that condition number channel worsen increases role in improvement weaken. spatial distributions reciprocal which corresponds locations obtained rank-deficient zones found AP, UE configurations, depicts RIS-assisted MIMO also indicate not only varies with location, but affected by antenna array size orientation AP UE. In addition, has larger amount antennas than UE, it advantageous place near rather achieve better condition. Modulation coding schemes applied comparison witnessed. Beneficial suggestions deployment concluded according simulation results.