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arXiv · 2107.09836

Bidirectional Approximate Message Passing for RIS-Assisted Multi-User MISO Communications

Li Wei·Chongwen Huang·Qinghua Guo·Zhaoyang Zhang·Merouane Debbah·Chau Yuen
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Abstract

Reconfigurable intelligent surfaces (RISs) have been recently considered as a promising candidate for energy-efficient solutions in future wireless networks. Their dynamic and lowpower configuration enables coverage extension, massive connectivity, and low-latency communications. Due to a large number of unknown variables referring to the RIS unit elements and the transmitted signals, channel estimation and signal recovery in RIS-based systems are the ones of the most critical technical challenges. To address this problem, we focus on the RIS-assisted multi-user wireless communication system and present a joint channel estimation and signal recovery algorithm in this paper. Specifically, we propose a bidirectional approximate message passing algorithm that applies the Taylor series expansion and Gaussian approximation to simplify the sum-product algorithm in the formulated problem. Our simulation results show that the proposed algorithm shows the superiority over a state-of-art benchmark method. We also provide insights on the impact of different RIS parameter settings on the proposed algorithms.

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Li Wei, Chongwen Huang, Qinghua Guo, Zhaoyang Zhang, Merouane Debbah, Chau Yuen. 2021-07-21. Bidirectional Approximate Message Passing for RIS-Assisted Multi-User MISO Communications. https://arxiv.org/abs/2107.09836

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