Large Intelligent Surface Aided Multiuser MIMO: Passive Beamforming and Information Transfer

This paper investigates the passive beamforming and information transfer (PBIT) technique for the large intelligent surface (LIS) aided multiuser multiple-input multiple-output (MuMIMO) systems, where the LIS is deployed to enhance the primary communication via passive beamforming and simultaneously deliver its private data via spatial modulation. For the passive beamforming design, we propose to maximize the sum channel capacity of the LIS-aided Mu-MIMO systems and formulate the maximization problem as a two-step stochastic program. An efficient sample average approximation based iterative algorithm is developed for the passive beamforming design. For the receiver design, the signal detection at the receiver is a bilinear estimation problem since the LIS data are multiplicatively modulated onto the reflected signals of the reflecting elements. To solve this problem, we develop a turbo message passing algorithm in which the bilinear estimation problem is divided into two subproblems: one for the estimation of the user signals and the other for the estimation of the LIS data. Extensive simulation results are provided to demonstrate the advantages of our passive beamforming and receiver designs.