Multi-Stream Beam-Training for mmWave MIMO Networks

Abstract

Multi-stream 60 GHz communication has the potential to achieve data rates up to 100 Gbps via multiplexing multiple data streams. Unfortunately, establishing multi-stream directional links can be a high overhead procedure as the search space increases with the number of spatial streams and the product of AP-client beam resolution. In this paper, we present MUlti-stream beam-Training for mm-wavE networks (MUTE) a novel system that leverages channel sparsity, GHz-scale sampling rate, and the knowledge of mm-Wave RF codebook beam patterns to construct a set of candidate beams for multi-stream beam steering. In 60 GHz WLANs, the AP establishes and maintains a directional link with every client through periodic beam training. MUTE repurposes these beam acquisition sweeps to estimate the Power Delay Profile (PDP) of each beam with zero additional overhead. Coupling PDP estimates with beam pattern knowledge, MUTE selects a set of candidate beams that capture diverse or ideally orthogonal paths to obtain maximum stream separability. Our experiments demonstrate that MUTE achieves 90% of the maximum achievable aggregate rate while incurring only 0.04% of exhaustive search's training overhead. CCS CONCEPTS • Networks → Network protocol design; Wireless local area networks; Network protocols;

A real-time experimentation platform for sub-6 GHz and millimeter-wave MIMO systems

“…The X60 system is based on a commercial platform implementing physical and MAC layers, integrating either horn antennas or small phased arrays. It was designed for SISO channels but has also been used for simple low-order MIMO experiments [7]. The mm-FLEX platform [11] includes fast antenna reconfiguration and full IEEE 802.11ad capability, but a potential extension of that system to multiple spatial streams would require multi-FPGA synchronization.…”

Demystifying millimeter-wave V2X

“…The potential of spatial reuse in mmWave networks has been widely studied [83][84][85]. Recent research investigated hybrid beamforming [86,87] and user selection for mmWave MU-MIMO [88], and proposed to find best analog configurations for multi-stream beams [89]. In contrast, our work discusses the feasibility of mmWave MU-MIMO using channel and spatial orthogonal multiplexing specifically for V2X scenarios.…”

X-Array

“…Then the AP collects CSI feedback of the clients' selected beams and further performs digital precoding to realize hybrid beamforming. Recent work designed algorithms to group the clients [58] or estimate the mmWave MIMO channel [59,60], assuming detailed CSI feedback is available. As discussed in Sec.…”