Next-Generation Mobile Communication Systems for Ambient-Assisted Living in Smart City - Massive Mimo Downlink Precoding for Next-Generation Mobile Communication Systems(1/3)

To achieve the goal of the smart city, information and communication technologies are used to enhance the interactivity of urban services and to reduce the resource consumption. This integrated project will develop the next-generation wireless mobile communication techniques and video processing techniques for ambient-assisted living in the smart city. We aim to build up the safety and security shield for ambient assisted living by taking advantage of the image/video from surveillance cameras near the streets and the dashboard cameras equipped in the cars, and then process the image/video by intelligent analysis, information extraction, multiple target tracking and event detection. Through the dense deployment of small cells in the city, the advanced wireless communication techniques are also studied and adopted to aid the emergence alert, processing procedure, and video streaming. To provide reliable and real-time communication quality, the following key features in the next-generation mobile communication systems will be developed, including software-defined network, low end-to-end link latency, and massive multiple-input multiple-output antenna array. The signal flow of the integrated system covers from application layer, media-access-control layer, and physical layer. The solution for ambient-assisted living in smart cities will be provided to enhance user experience.The sub-project aims to develop the massive multiple-input multiple-output downlink precoding technique, which refers to a large number of antennas equipped in the base-station. To reduce the system complexity, hybrid precoding architecture will be adopted, which uses analog precoding by phase shifters in the radio-frequency front-end and digital precoding in the baseband. The full-dimension milli-meter wave channel model, including the distribution statistics of power, delay, departure/arrival azimuth angle, and zenith angle, will be constructed for system performance evaluation. The precoding unit at the transmitter side of the base-station must remove or suppress the multiple access interference and also the inter-cell interference. Besides, spatial-division multiple access can be supported with the beamforming effect. The time-varying channel response due to mobility will be also considered and thus beam tracking algorithm will be studied and designed. Because high-throughput is the targets of the next-generation mobile communication systems, the precoding scheme will be implemented as a hardware accelerator in 40nm CMOS technology to demonstrate the feasibility. Hence, the design striking a good balance between complexity and performance is the major concern. The use of massive MIMO in wireless network has thepotential to improve energy efficiency, spectral efficiency, and link quality.