Channel Estimation for Intelligent Reflecting Surface Assisted Multiuser Communications: Framework, Algorithms, and Analysis

In intelligent reflecting surface (IRS) assisted communication systems, the acquisition of channel state information is a crucial impediment for achieving the beamforming gain of IRS because of the considerable overhead required for channel estimation. Specifically, under the current beamforming design for IRS-assisted communications, in total KMN+KM channel coefficients should be estimated, where K, N and M denote the numbers of users, IRS reflecting elements, and antennas at the base station (BS), respectively. For the first time in the literature, this paper points out that despite the vast number of channel coefficients that should be estimated, significant redundancy exists in the user-IRS-BS reflected…

• NN
  National Natural Science Foundation of China

  Awards: 61629101, 2018B030338001, 2018YFB1800800, NSFC-61629101, 2017ZT07X152
• HK
  Hong Kong Polytechnic University

  Award: P0030001
• SP
  Special Project for Research and Development in Key areas of Guangdong Province

  Award: 2018B030338001