Our era is witnessing the emergence of innumerable new wireless applications. Examples include autonomous driving via connected vehicles, high-definition live streaming, pervasive information showers, internet of things (IoT), and terrestrial-satellite cooperation, just to name a few. However, today's wireless solutions are lagging behind in supporting these applications. For example, the stereoscopic high-dynamic range 360-degree video for live streaming requires 2-20 Gbps data rate. This far exceeds the capability of our current wireless networks. mm-wave radios with multi-gigahertz bandwidth and massive antenna arrays have the potential to bring many wireless applications from dream to reality. However, their potentials come with formidable challenges. On the one hand, mm-wave experiences complicated and time-varying electromagnetic propagation effects that are distinct from current wireless systems. On the other hand, the mm-wave system design is subject to the unique hybrid digital and analog structures due to cost considerations. This project develops paradigm-shifting solutions to these unprecedented challenges and paves the road towards widespread deployment of mm-wave technology in both static and mobile scenarios. The research outcomes are expected to advance the state-of-the-art wireless technologies and improve the readiness of hybrid mm-wave massive MIMO deployment with a massive number of mobile users. The project has an integrated education plan to prepare workforce for future challenges in wireless communications and sensing.
The research consists of pioneering efforts dedicated to the design and optimization of mm-wave massive MIMO transceivers with a hybrid structure, under challenging doubly-selective channel propagation, and with multiple user devices that may be equipped with ultra-low-complexity structures. First, a hybrid doubly-selective mm-wave massive MIMO channel estimator will be developed by exploiting the double sparsity of the channel. Based on the estimated channel, an inherently wideband approach will be adopted to design the multi-user hybrid transceivers. These transceivers will be further optimized to exploit the spatial multiplexing gain, despite the very small number of radio-frequency (RF) chains at the hybrid transceivers. On top of all these, efforts will also be made to address extreme system design and optimization challenges associated with ultra-low-complexity hybrid transceivers with ultra-low-bit-depth analog-to-digital converters and/or ultra-low-bit-count analog phase shifter networks.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
