大型隨意網路之分佈式傳輸排程與功率控制研究 Distributed Scheduling and Power Control in Large-Scale Ad Hoc Networks

In this thesis, we introduce two distinct approaches – distance-aware scheduling and 2layer discrete power control (DPC), which are able to enhance the transmission capacity of a large-scale wireless ad hoc network. Transmission capacity is an area spectrum efficiency metric of a wireless ad hoc network with an outage constraint. The motivation of studying these two approaches is to investigate whether limiting multiuser interference is an effective means of boosting the network capacity of a wireless ad hoc network. First, we propose an opportunistic scheduling scheme that exploits distance-aware conditions between a transmitter and its intended receiver, termed distance-aware scheduling (DAS) scheme. A transmitter with DAS schedules a transmission when the distance satisfies an density-based dynamic threshold constraint. Next, we propose the 2-layer DPC scheme for DAS since such 2-layer DPC can reduce interference if it is properly designed to satisfy a certain condition. The power control scaling law for the 2-layer DPC scheme is developed, which is able to strictly outperform the constant power control scheme (i.e., no power control scheme) in terms of the average signal-to-interference ratio. Both of the proposed schemes are essentially characterized by transmission distance and can achieve higher area spectrum efficiency due to interference reduction. Index Terms – Discrete power control, Distributed opportunistic scheduling, Ad hoc network, Transmission capacity (TC)