The 5th International Conference on
Mobile • Military • Maritime IT Convergence

Prof. Hien Quoc Ngo

Professor of Wireless Communications, Queen's University Belfast, U.K.

With the dramatic growth of wireless devices and services/applications (such as ubiquitous intelligence and computing, smart X, immersive extended reality), future wireless networks must meet the following key requirements: (1) manage many devices simultaneously; (2) provide high throughput for each device; (3) ensure high energy efficiency; and (4) offer strong security services. This can be achieved through massive multiple-input and multiple-output (MIMO) technology, where many antennas coherently serve multiple users in the same time-frequency resource. Massive MIMO offers high array gain and multiplexing gain, thus provides huge spectral and energy efficiency with simple linear processing. Depending on the system topology, massive MIMO is categorized into two main systems: cellular (collocated) massive MIMO and cell-free massive MIMO. Cellular massive MIMO is becoming mature and is one of the core technologies for 5G networks. The first version of 5G NR with massive MIMO was standardized by 3GPP, with more advanced technologies under development for future releases of 5G standards. In contrast, cell-free massive MIMO has not yet been deployed in practice. It uses massive MIMO technology to eliminate cells, thereby overcoming inter-cell interference, an inherent limitation of cellular systems. As a result, cell-free massive MIMO has attracted significant research attention and is considered one of the most promising technologies for 6G networks and beyond. This lecture will provide comprehensive overview of state-of-the-art research on cellular and cell-free massive MIMO. Fundamental aspects, key results, and future directions of these systems will be discussed in detail. The discussion will serve as a good roadmap for start-up and consequently motivates researchers from both industry and academia to work in this area..