Rate Region of MIMO RIS-assisted Broadcast Channels with Rate Splitting and Improper Signaling

Conference: WSA & SCC 2023 - 26th International ITG Workshop on Smart Antennas and 13th Conference on Systems, Communications, and Coding
02/27/2023 at Braunschweig, Germany

Proceedings: ITG-Fb. 308: WSA & SCC 2023

Pages: 6Language: englishTyp: PDF

Authors:
Soleymani, Mohammad (Signal & System Theory Group, Universität Paderborn, Germany)
Santamaria, Ignacio (Dept. Communications Engineering, Universidad de Cantabria, Spain)
Jorswieck, Eduard (Institute for Communications Technology, Technische Universität Braunschweig, Germany)

Abstract:
In this paper, we study the achievable rate region of 1-layer rate splitting (RS) in the presence of hardware impairment (HWI) and improper Gaussian signaling (IGS) for a single-cell reconfigurable intelligent surface (RIS) assisted broadcast channel (BC). We assume that the transceivers may suffer from an imbalance in in-band and quadrature signals, which is known as I/Q imbalance (IQI). The received signal and noise can be improper when there exists IQI. Therefore, we employ IGS to compensate for IQI as well as to manage interference. Our results show that RS and RIS can significantly enlarge the rate region, where the role of RS is to manage interference while RIS mainly improves the coverage.