Near-Field Communications for Millimeter-Wave Ultra-Massive MIMO Wireless Networks
DescriptionThe deployment of the latest fifth-generation (5G) wireless networks has tremendously reshaped every aspect of our daily life and vitalized advanced development in the industry. Qualcomm estimated that 5G will power the digital economy in global economic value by US$ 13.2 trillion by 2035. Inspired by such impactful success, both academia and industry have started to blueprint the next-generation 6G wireless networks. To support a plethora of thrilling applications, e.g., the Internet of Everything (IoE), big data analytics, and augmented reality (AR), 6G is expected to achieve extremely high data rates, ultra-wide frequency bands, and massive connections. These stringent requirements call for revolutionary and transformative wireless technologies for 6G network evolution. Millimeter-wave (mm-wave) communication at 30 GHz to 300 GHz is such a disruptive technology as it can crack the spectrum crunch crisis in current cellular systems and free up spectrum in the order of GHz. Meanwhile, with the significantly reduced wavelength of mm-wave signals, hundreds of thousands of antenna elements can be compactly deployed at transceivers, agreeing with the newly-emerging concept of ultra-massive multiple-input multiple-output (UM-MIMO). Nevertheless, leveraging UM-MIMO at mm-wave bands is not merely a quantitative increase in both antenna size and carrier frequency, but more importantly, a qualitative paradigm shift from conventional far-field communications to its near-field counterpart. In particular, the enlarged antenna aperture and shortened wavelength jointly expand the region defined as the near field, which was normally overlooked in traditional wireless communications. Hence, this project will focus on near-field mm-wave UM-MIMO communications, which is anticipated to be the typical transmission scenario in next-generation 6G systems. However, the abrupt transformation of communication mode introduces formidable challenges, which shall be addressed in this project by developing novel physical (PHY) and medium access control (MAC) layer techniques for near-field mm-wave UM-MIMO systems, respectively. First, as the channel dimension becomes exceedingly large, the complexity of signal processing for channel estimation and beamforming is daunting. Of particular interest is the development of effective algorithms taking into account the unique characteristics of near-field mm-wave channels and hardware limitations. Second, to achieve blockage-free near-field mm-wave communications, it is of paramount importance to create scalable user scheduling considering visible regions of UM-MIMO arrays and deployment strategies of intelligent reflecting surfaces with theoretical supports. Finally, as future wireless networks tend to be highly complex and heterogeneous, practical hybrid near- and far-field communications will be investigated. Special attention shall be paid to utilizing smart antenna selection methods for versatile hybrid-field mm-wave UM-MIMO systems.
|Effective start/end date
|1/09/23 → …