Optimal Resource Allocation in Heterogeneous Networks.

摘要

Cooperative Cognitive Radio Networks (CCRNs) incorporate cooperative communications and cognitive radio networks, in which, primary users lease their spectrum to secondary users, and in exchange, the primary users leverage secondary users as cooperative relays to enhance their own throughput. Many existing cellular providers are eager to offload traffic from their increasingly congested 3G and 4G networks to small cell technologies like IEEE 802.11 based Wireless Local Area Networks (WLANs) and LTE based pico cells. On the other hand, small cells are comparatively easy and cost effective to deploy, and provide good channel reuse, but are severely constrained by spectrum congestion and interference. However, by employing a CCRN scheme, the mobile operator can lease unused licensed channels to the small cells, thereby reducing spectrum interference and improving spatial reuse in the network. Hence, cooperation between the mobile operators and the small cell owners can bring significant improvements in the system capacity and throughput for the users. In this dissertation, we propose an implementation of the CCRN framework applied to small technologies such as IEEE 802.11 WLANs and LTE Advanced networks employing an Enhanced Inter-Cell Interference Coordination (eICIC) scheme. The cooperation is cast as a two-player bargaining game where the two players are the primary users (users of the mobile operator) and the secondary users (users of the small cell before spectrum leasing), who bargain for either throughput share or channel access time share. The optimal resource allocation that ensures efficiency as well as fairness among users is provided by the Nash solution. Simulation results show that the both types of users achieve higher throughput via the proposed CCRN scheme, thus providing the mobile operator and the private small cell provider with incentives for cooperation.