Research Topics

Reconfigurable intelligent surface (RIS) is a large 2D surface of metamaterial, which is composed of passive scattering elements. Each element can be controlled to change the electromagnetic properties such as phase shift of the reflection of incident signals to make better communication channels. 

RIS is a promising technology for future wireless communication systems due to its energy efficiency and various applications. In contrast to the conventional systems, however, RIS-assisted systems pose various implementational issues as the transmitter-RIS-receiver cascade channel complicates the system design. Research about the RIS-assisted wireless communication system includes joint active (at base stations) and passive (at RIS) beamforming, channel estimation of reflected signals, deploying multiple RISs, etc.

ISAC refers to the seamless integration of sensing and communication functionality into a system. ISAC is expected to improve spectral and energy efficiencies considerably while reducing both hardware and signaling costs. This integration increases awareness of surrounding conditions, enabling applications such as environmental monitoring, surveillance, medical monitoring, and smart infrastructure management.

Massive Multiple-Input Multiple-Output (MIMO) is a key enabling technology for modern wireless communication systems, particularly in mmWave communications in 5G and beyond. It involves the use of a large number of antennas at the base station (BS) to serve multiple users simultaneously in the same time-frequency resources. By leveraging spatial diversity and beamforming, massive MIMO significantly improves spectral efficiency, energy efficiency, and system reliability.