Resource Allocation with Interference Avoidance in OFDMA Femtocell Networks

Abstract

Abstract-Interference control and quality-of-service (QoS) awareness are the major challenges for resource management in orthogonal frequency-division multiple access femtocell networks. This paper investigates a self-organization strategy for physical resource block (PRB) allocation with QoS constraints to avoid the co-channel and co-tiered interference. Femtocell self-organization including self-configuration and self-optimization is proposed to manage the large femtocell networks. We formulate the optimization problem for PRB assignments where multiple QoS classes for different services can be supported, and interference between femtocells can be completely avoided. The proposed formulation pursues the maximization of PRB efficiency. A greedy algorithm is developed to solve the resource allocation formulation. In the simulations, the proposed approach is observed to increase the system throughput by over 13% without femtocell interference. Simulations also demonstrate that the rejection ratios of all QoS classes are low and mostly below 10%. Moreover, the proposed approach improves the PRB efficiency by over 82% in low-loading scenario and 13% in high-loading scenario.Index Terms-Femtocell, interference avoidance, orthogonal frequency-division multiple access (OFDMA), resource allocation, resource reuse.

Self-organized Spectrum Access in Small-cell Networks with Dynamic Loads

“…The coverage radius of a small-cell was 10m. Like many previous studies [15], in order to simplify our analysis of the small-cell network, when modelling the propagation environment we only considered path loss. The path loss between two SBSs, was assumed equal to…”

“…The problem of resource allocation and co-tier interference mitigation in small-cell networks has been investigated widely [11][12][13][14]. In many existing works [15][16][17], a central management system or controller is necessary for handling resource allocation and interference mitigation, which leads to significant signaling overhead between the controller and the small-cells. In [15], the authors utilized a femtocell management system to avoid co-channel and co-tier interference.…”

“…In many existing works [15][16][17], a central management system or controller is necessary for handling resource allocation and interference mitigation, which leads to significant signaling overhead between the controller and the small-cells. In [15], the authors utilized a femtocell management system to avoid co-channel and co-tier interference. In [16], the authors proposed a semi-centralized interference management scheme, which was based on joint clustering and resource allocation for small-cells.…”

“…Also, the monitoring of instantaneous channel gains of the SUs will lead to extensive signaling and huge amount of information transmission overhead. In our model, the average channel gains measured by SBSs are used for channel allocation, similar to [15]. Each small-cell performs downlink measurements of interference signal and noise power levels in each available channel.…”

Mobility and load aware radio resource management in OFDMA femtocell networks

“…Radio resource management (RRM) is an important issue in heterogeneous networks. Given that the FAPs share the same resources with the macro base station (MBS) and also the other FAPs, RRM should mitigate the interference level more carefully [2]. FAPs can be employed in different access modes, namely open, closed, and hybrid access.…”