Spectral-efficient resource allocation for mixed services in OFDMA-based 5G heterogeneous networks

摘要

One of the principal thrusts of proposed 5G networks is the provisioning of mixed services or heterogeneous Quality-of-Service (QoS) which includes delay-sensitive (DS) and delay tolerant (DT) services. ududGuaranteeing the fairness in data rate among end-users in such a complex network brings many challenges. In this paper, we consider heterogeneous QoS and fairness in the problem of spectrally efficient resource allocation in OFDMA based 5G heterogeneous networks (HetNets) with femtocells. ududWe aim to maximize the total capacity of all femtocells while satisfying the following: fairness constraint for DT users, minimum throughput for DS users, cross-tier interference threshold of femtocell HetNets and exclusive property of OFDMA subchannels. The formulated problem is combinatorial and non-convex due to the integer constraint of OFDMA subchannels and non-affine equality constraint of the fairness. ududTo make the problem more tractable, we propose to maximise the overall throughput over instantaneous data rate instead of power and subchannel. By doing this, the fairness equality becomes affine on instantaneous data rate. The feasible domain of the problem is redefined with the constraints of subchannels readily included. ududThe transformed problem takes the standard convex form which is much simpler and is easily solved using the Lagrangian dual method. The proposed algorithm has a low complexity and provides a higher spectral efficiency compared to existing algorithms.