Outer Loop Link Adaptation Based on User Multiplexing for Generalized Approximate Message Passing in Massive MIMO

• Published in: 2024 IEEE Wireless Communications and Networking Conference (WCNC) pp. 1 - 6
• Main Authors: Doi, Takanobu, Shikida, Jun, Shirase, Daichi, Muraoka, Kazushi, Ishii, Naoto, Takahashi, Takumi, Ibi, Shinsuke
• Format: Conference Proceeding
• Language: English
• Published: IEEE 21.04.2024
• Subjects: Approximation algorithms; generalized approximate message passing (GAMP); Heuristic algorithms; Interference; iterative multi-user detection; massive MIMO; Message passing; Multiplexing; Multiuser detection; outer loop link adaptation (OLLA); Prediction algorithms; scheduling
• ISSN: 1558-2612
• DOI: 10.1109/WCNC57260.2024.10570905

This paper proposes an outer loop link adaptation (OLLA) algorithm for massive multi-user multi-input multi-output (MIMO) systems that employs uplink multi-user detection (MUD) based on generalized approximate message passing (GAMP). The contribution aims to improve uplink system throughput performance for future beyond-fifth-generation mo-bile communication systems by designing a novel scheduler that can select spatially multiplexed user equipment (UE) devices and their modulation and coding schemes (MCSs), considering the high detection accuracy provided by the GAMP-based MUD. To achieve this, we propose an OLLA algorithm that accu-rately predicts the signal-to-interference and noise power ratio (SINR) that each UE can achieve after the GAMP-based MUD. Specifically, the proposed method can dynamically optimize the scheduler according to the iterative detection characteristics of GAMP by introducing a mechanism to correct the predicted SINR separately for each combination of spatially multiplexed UEs. System-level simulation results indicate that adjusting our OLLA algorithm achieves a 50% higher throughput than the conventional OLLA algorithm when applied to GAMP.