Electrical engineering

Channel (broadcasting)

Spectral efficiency

Topology (electrical circuits)

Quantization (signal processing)

Mathematics

Wireless

Algorithm

Ergodic theory

Channel state information

Engineering

Mathematical analysis

Electronic engineering

Degradation (telecommunications)

Computer science

Telecommunications

Upper and lower bounds

IEEE Transactions on Vehicular Technology

Large intelligent surface (LIS)-assisted wireless communications have drawn attention worldwide. With the use of low-cost LIS on building walls, signals can be reflected by the LIS and sent out along desired directions by controlling its phases, thereby providing supplementary links for wireless communication systems. In this paper, we evaluate the performance of an LIS-assisted large-scale antenna system by formulating a tight upper bound of the ergodic spectral efficiency and investigate the effect of the phase shifts on the ergodic spectral efficiency in different propagation scenarios. In particular, we propose an optimal phase shift design based on the upper bound of the ergodic spectral efficiency and statistical channel state information. Furthermore, we derive the requirement on the quantization bits of the LIS to promise an acceptable spectral efficiency degradation. Numerical results show that using the proposed phase shift design can achieve the maximum ergodic spectral efficiency, and a 2-bit quantizer is sufficient to ensure spectral efficiency degradation of no more than 1 bit/s/Hz.

Large Intelligent Surface-Assisted Wireless Communication Exploiting Statistical CSI