Date & Time: 

   2024 /10 / 25  (Fri) 14:20 - 16:20

 

Location: 

   Delta Building R216, NTHU

 

Speaker: 

    陳榮杰 教授

   國立成功大學電腦與通信工程研究所

 

Topic: 

  Enhancing MU-MISO Systems With Irregular and STAR Reconfigurable Intelligent Surfaces

 

Abstract: 

   In this talk, we investigate the use of reconfigurable intelligent surfaces (RIS) to enhance multiuser multiple-input single-output (MU-MISO) wireless communication systems. Traditional RIS configurations rely heavily on the number of elements for performance gains. To address this, we adopt an "irregular RIS," where only a selected subset of elements is used, improving performance while keeping power consumption low. However, optimizing the joint design of precoders, RIS coefficients, and element selection remains challenging. To solve this, we employ zero-forcing (ZF) precoding combined with a probability learning algorithm for joint optimization. Our approach offers improved performance, reduced computational complexity, and faster execution compared to existing methods.

 Despite these advances, irregular RIS cannot fully support comprehensive wireless transmission. To address this, we propose the use of simultaneously transmitting and reflecting RIS (STAR-RIS), which we also optimize using the ZF-based learning framework, yielding superior results in both performance and efficiency. Finally, we combine both irregular RIS and STAR-RIS, optimizing them within the same framework to further enhance system performance.

 

Autobiography: 

  Jung-Chieh Chen (陳榮杰) received his B.S. degree in Electrical Engineering from the Tatung Institute of Technology, Taipei, Taiwan, his M.S. degree in Electrical Engineering from National Chung Cheng University, Chiayi, Taiwan, and his Ph.D. degree in Communications Engineering from National Tsing Hua University, Hsinchu, Taiwan. He joined National Kaohsiung Normal University, Kaohsiung, Taiwan, as an Assistant Professor in August 2005, subsequently being promoted to Associate Professor in March 2009 and to Full Professor in March 2012. Since February 2022, he has held the position of Full Professor in the Department of Electrical Engineering at National Cheng Kung University, Tainan, Taiwan. His research interests encompass wireless communication systems, radio resource management, stochastic optimization methods, and signal processing for communications. Prof. Chen currently serves as an Editor for the IEEE Transactions on Vehicular Technology and the IEEE Wireless Communications Letters. He is also an Associate Editor for the IET Signal Processing. He was Chair of the Tainan Chapter of the IEEE Communications Society from 2022 to 2023.