Downlink Resource Allocation in Multiuser Cell-free MIMO Networks with\n User-centric Clustering

2021/08/13 by Hussein A. Ammar, Ammar, Hussein A., Raviraj Adve +7 · 5 citations
Computer Science · Engineering · #Advanced MIMO Systems Optimization #Cooperative Communication and Network Coding #FOS: Computer and information sciences #FOS: Electrical engineering #Information Theory (cs.IT) #Millimeter-Wave Propagation and Modeling #Networking and Internet Architecture (cs.NI) #Performance (cs.PF) #Signal Processing (eess.SP) #Systems and Control (eess.SY) #electronic engineering #information engineering

paper · pdf · doi:10.48550/arxiv.2108.06316

openalex publication_date 2021/08/13 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28

Abstract

In this paper, we optimize user scheduling, power allocation and beamforming\nin distributed multiple-input multiple-output (MIMO) networks implementing\nuser-centric clustering. We study both the coherent and non-coherent\ntransmission modes, formulating a weighted sum rate maximization problem for\neach; finding the optimal solution to these problems is known to be NP-hard. We\nuse tools from fractional programming, block coordinate descent, and\ncompressive sensing to construct an algorithm that optimizes the beamforming\nweights and user scheduling and converges in a smooth non-decreasing pattern.\nChannel state information (CSI) being crucial for optimization, we highlight\nthe importance of employing a low-overhead pilot assignment policy for\nscheduling problems. In this regard, we use a variant of hierarchical\nagglomerative clustering, which provides a suboptimal, but feasible, pilot\nassignment scheme; for our cell-free case, we formulate an area-based pilot\nreuse factor. Our results show that our scheme provides large gains in the\nlong-term network sum spectral efficiency compared to benchmark schemes such as\nzero-forcing and conjugate beamforming (with round-robin scheduling)\nrespectively. Furthermore, the results show the superiority of coherent\ntransmission compared to the non-coherent mode under ideal and imperfect CSI\nfor the area-based pilot-reuse factors we consider.\n

Citations

• An Iteratively Weighted MMSE Approach to Distributed Sum-Utility Maximization for a MIMO Interfering Broadcast Channel
• Scalable Cell-Free Massive MIMO Systems

Cited by

• Linear Attention for Joint Power Optimization and User-Centric Clustering in Cell-Free Networks
• Downlink Power Allocation for STAR-RIS-Assisted Cell-Free Massive MIMO with Multi-antenna Users
• Cluster-wise processing in fronthaul-aware cell-free massive MIMO systems
• Handoff Design in User-Centric Cell-Free Massive MIMO Networks Using DRL
• Coverage Probability and Average Rate Analysis of Hybrid Cellular and Cell-free Network

Related

• Resource Allocation and Scheduling in Non-coherent User-centric Cell-free MIMO
• Distributed Resource Allocation Optimization for User-Centric Cell-Free\n MIMO Networks
• Sequential Multiuser Scheduling and Power Allocation for Cell-Free Multiple-Antenna Networks
• User-Centric Clustering Under Fairness Scheduling in Cell-Free Massive MIMO
• Study of Clustering Techniques and Scheduling Algorithms with Fairness for Cell-Free MIMO Networks