Enable omnidirectional coverage using array of phased array (APA) architecture
We propose X-Array, which jointly selects the arrays and beams, and applies a dynamic co-phasing mechanism to ensure different arrays’ signals enhance each other. X-Array also incorporates a link recovery mechanism to identify alternative arrays/beams that can efficiently recover the link from outage. We have implemented X-Array on a commodity 802.11ad APA radio. Our experiments demonstrate that X-Array can approach omni-directional coverage and maintain high performance in spite of link dynamics.
Leverage robotic relay to realize room-level seamless coverage
Our design enables a robot relay automatically constructs the geometry/reflectivity of the environment using measured RSS only, then navigates itself along an optimal moving trajectory, and ensures continuous connectivity for the client despite environment/human dynamics. Our field trials demonstrate that our design can achieve nearly full coverage in dynamic environments, even with constrained speed and mobility region.
Model-driven beam prediction to achieve robust mmWave connection under mobility and blockage
Our design leverages the observation that mmWave spatial channel profiles (SCP) of nearby locations are highly-correlated, so we can reconstruct the SCP as the Tx/Rx moves with possible blockages, using a reverse-engineering approach without explicit channel scanning. We also design and incorporate greedy approximation algorithms to resolve the high computational complexity issue conventionally involved with reverse-engineering. In this way, we can predict new optimal beams and realign links for mobile/blocked users with minimal overhead.