[Paper Review] Network Multiple-Input and Multiple-Output for Wireless Local Area Networks

Hong Huang, Hajar Barani+1 more|arXiv (Cornell University)|Feb 8, 2014

Cooperative Communication and Network Coding19 references3 citations

TL;DR

This paper introduces network multiple-input and multiple-output (netMIMO) for wireless local area networks, enabling access points to cooperate as a virtual MIMO node to reduce interference and contention, thereby significantly increasing network capacity. It presents representative netMIMO techniques including interference alignment, distributed synchronization, and channel access protocols for MIMO cooperation.

ABSTRACT

This paper presents a tutorial for network multiple-input and multiple-output (netMIMO) in wireless local area networks (WLAN). Wireless traffic demand is growing exponentially. NetMIMO allows access points (APs) in a WLAN to cooperate in their transmissions as if the APs form a single virtual MIMO node. NetMIMO can significantly increase network capacity by reducing interferences and contentions through the cooperation of the APs. This paper covers a few representative netMIMO methods, ranging from interference alignment and cancelation, channel access protocol to allow MIMO nodes to join ongoing transmissions, distributed synchronization, to interference and contention mitigation in multiple contention domains. We believe the netMIMO methods described here are just the beginning of the new technologies to address the challenge of ever-increasing wireless traffic demand, and the future will see even more new developments in this field.

Motivation & Objective

• To address the exponentially growing demand for wireless traffic in modern WLANs.
• To reduce interference and contention in dense wireless networks through coordinated access point cooperation.
• To present practical netMIMO methods that enable APs to function as a virtual MIMO array.
• To lay the foundation for future advancements in cooperative MIMO technologies for next-generation WLANs.

Proposed method

• Utilizes interference alignment and cancellation techniques to manage inter-cell interference in multi-AP environments.
• Employs channel access protocols that allow MIMO nodes to join ongoing transmissions, improving spectrum efficiency.
• Implements distributed synchronization mechanisms to align transmission timing across multiple access points.
• Introduces interference and contention mitigation strategies in multiple contention domains to enhance network scalability.
• Enables cooperative beamforming by treating multiple APs as a single virtual MIMO transmitter.
• Applies coordination protocols that allow APs to jointly manage transmission scheduling and resource allocation.

Experimental results

Research questions

• RQ1 How can multiple access points in a WLAN be coordinated to function as a single virtual MIMO node?
• RQ2 What channel access mechanisms allow MIMO-capable nodes to join ongoing transmissions without causing collisions?
• RQ3 How can distributed synchronization be achieved among geographically separated APs to enable coherent transmission?
• RQ4 What techniques effectively mitigate interference and contention in multiple contention domains within a netMIMO system?
• RQ5 How do netMIMO techniques improve network capacity compared to conventional non-cooperative MIMO systems?

Key findings

• NetMIMO significantly increases network capacity by enabling coordinated transmission across multiple access points.
• Interference alignment and cancellation techniques reduce inter-cell interference, improving spectral efficiency.
• Distributed synchronization allows APs to maintain timing coherence without centralized control.
• Channel access protocols that support MIMO cooperation reduce medium access contention and improve throughput.
• Mitigation of interference and contention in multiple contention domains enhances scalability in dense WLAN deployments.
• The proposed netMIMO methods demonstrate a foundational framework for future cooperative MIMO innovations in wireless networks.