Optimizing Throughput Performance in Distributed MIMO Wi-Fi Networks using Deep Reinforcement Learning

TL;DR

This work constructs a DRL framework through which a learning agent interacts with a D-MIMO Wi-Fi network, learns about the network environment, and successfully converges to policies which address the aforementioned problems.

Abstract

This paper explores the feasibility of leveraging concepts from deep reinforcement learning (DRL) to enable dynamic resource management in Wi-Fi networks implementing distributed multi-user MIMO (D-MIMO). D-MIMO is a technique by which a set of wireless access points are synchronized and grouped together to jointly serve multiple users simultaneously. This paper addresses two dynamic resource management problems pertaining to D-MIMO Wi-Fi networks: (i) channel assignment of D-MIMO groups, and (ii) deciding how to cluster access points to form D-MIMO groups, in order to maximize user throughput performance. These problems are known to be NP-Hard and only heuristic solutions exist in literature. We construct a DRL framework through which a learning agent interacts with a D-MIMO Wi-Fi network, learns about the network environment, and is successful in converging to policies which address the aforementioned problems. Through extensive simulations and on-line training based on D-MIMO Wi-Fi networks, this paper demonstrates the efficacy of DRL in achieving an improvement of 20% in user throughput performance compared to heuristic solutions, particularly when network conditions are dynamic. This work also showcases the effectiveness of DRL in meeting multiple network objectives simultaneously, for instance, maximizing throughput of users as well as fairness of throughput among them.

Figures (12)

• Figure 1: Representative architecture of a D-MIMO group. A group with M $\mathrm{RH}$s, with N antennas per $\mathrm{RH}$, can support M$\times$N simultaneous downlink streams.
• Figure 2: Cartoon example of dense deployment of Wi-Fi APs and D-MIMO $\mathrm{RH}$s. Frequency reuse factor is four with each channel represented by a unique color. Dotted circle represents the hearing range of an AP/$\mathrm{RH}$.
• Figure 3: A D-MIMO Wi-Fi network with $16$ groups (with four $\mathrm{RH}$s each), all assigned to the same channel. Triangles represent $\mathrm{RH}$s and circles represent users.
• Figure 4: Channel assignment based on a simple heuristic. Each color represents a unique non-overlapping channel.
• Figure 5: A D-MIMO Wi-Fi network with random external Wi-Fi interference in its vicinity. The interferers may operate in channels red, blue, yellow or green.