Dividing Control Scheme for Intelligent Reflecting Surfaces Towards the Realization of Multiple Simultaneous Connections

Research and development of Space-Air-Ground Integrated Network (SAGIN) systems, which can provide a wide range of communication support from space and the air, have been progressing as a way to achieve the 6G requirements of ultra coverage extension and ultra-large capacity. Additionally, the use of Intelligent Reflecting Surfaces (IRS) in SAGIN is expected to improve the overall system performance. An IRS is a radio-wave reflection device that can control the phase of an incident radio wave, and the direction of the radio-wave reflection can be arbitrarily selected by appropriate phase control. However, IRS cannot reflect radio waves in multiple directions at the same time basically, it is difficult to communicate with multiple simultaneous connections. Therefore, IRS dividing control is proposed as a control method to realize multiple simultaneous connections. The communication performance of IRS divisions depends on three control parameters: the number of the IRS divisions, the division pattern, and the beam assign pattern. Therefore, in this study the relationship between IRS dividing control and control parameters is discussed and verified by simulations. The simulation results show that the optimal number of divisions depends on the communication demand of the User Equipments (UEs) and their distance from the IRS. Further, the optimal division pattern and the beam assign pattern depend on the UE distribution.