Resource allocation optimization in heterogeneous wireless networks

Abstract

Wireless cellular networks are designed to provide network coverage over large areas and support many users. Most recently, studies in 3GPP LTE-advanced have looked at the deployment of heterogeneous wireless networks to improve system performance as well as to enhance network coverage, especially in-building coverage [1–6]. Heterogeneous wireless networks use a mix of higher tier macrocells to extend network reach and lower tier small cells to enhance performance within the same frequency band [1–6]. These smaller cells offload the traffic from the macrocells and connect the traffic to the cellular core network via broadband access networks. However, as user-installed small cells (femtocells) are often deployed in an ad hoc manner, this gives rise to the problem of interference between cells. For example, amacrocell with a femtocell or a femtocell with another femtocell. New resource allocation techniques are required to ensure that the users control their power to mitigate performance loss due to interference. To enhance decentralized deployment, users also need to adapt their power with minimal signaling overhead [1, 2]. For example, users in femtocell can use digital subscriber line (DSL) or cable modem to exchange messages through the cellular core network to adjust their transmit powers to reduce the interference caused to the macrocell users.