Examination Committee

Prof Alvin Yiu-cheong SO, SOSC/HKUST (Chairperson)
Prof Khaled BEN LETAIEF, ECE/HKUST (Thesis Supervisor)
Prof Yahong Rosa ZHENG, Department of Electrical and Computer Engineering, Missouri University of Science and Technology (External Examiner)
Prof Ross MURCH, ECE/HKUST
Prof Chin-Tau LEA, ECE/HKUST
Prof Qian ZHANG, CSE/HKUST
 

Abstract

The mobile data traffic is growing at an exponential rate. Network densification is commonly adopted to accommodate the increasing demand, which incurs a heavy burden on the backhaul links. Cache-enabled content-centric networking is considered as a promising approach to alleviate backhaul burden. Moreover, caching at mobile devices can facilitate device-to-device (D2D) communications, which can significantly improve spectrum efficiency. There are two phases in the cache-assisted D2D network. The first one is the caching placement phase, where the caching placement strategies are designed.  The other one is the content delivery phase, where the D2D links are specified and the contents are delivered over wireless channels.
 
While designing the caching placement, most previous works ignored user mobility, thus having limited practical applications. In this thesis, we take advantage of the user mobility pattern and propose mobility-aware caching placement strategies. Meanwhile, it is proved that the data offloading ratio, i.e., the percentage of the requested data delivered via D2D links rather than through base stations (BSs), increases with user moving speed. Moreover, due to the selfishness of mobile users, incentive mechanisms will be needed to motivate device caching. By taking advantage of the user mobility information, we design an incentive mechanism in a cache-assisted D2D network. 
 
In the content delivery phase, the user requests are served via D2D links. However, without appropriate network design, severe interference will be generated between the cellular and D2D links. Dynamic resource allocation is effective for managing interference in D2D networks. We therefore propose effective channel assignment algorithms for network utility maximization in a cellular network with underlaying D2D communications. A major innovation is the consideration of partial channel state information (CSI), i.e., the BS is assumed to be able to acquire partial instantaneous CSI of the cellular and D2D links, as well as, the interference links.