Dynamic downlink resource allocation and access strategy for femtocell networks

Abstract

Femtocells are small, low‐power cellular base stations with high potential for coverage extension and offloading voice and wireless data. In this paper, we study the problem of joint access control and spectrum resource allocation in a 2‐tier femtocell network with 1 macro base station and multiple Femto access points (FAPs). The objective is to maximize the overall network capacity, while guaranteeing the quality of service requirement of all user equipments. We develop an access scheme for macro user equipments and a spectrum allocation mechanism for the FAPs. Spectrum allocation is used as an incentive mechanism to encourage FAPs to serve more macro user equipments. We also derive an upper bound of the network‐wide capacity through a reformulation of the problem. The proposed algorithms are validated, and the upper bound is shown to be quite accurate in the simulation study.

Joint distributed cell association and interference management in OFDMA‐based heterogeneous networks

“…Several studies have been conducted on resource allocation and interference management in specific architectures of heterogeneous networks. 8,14,19,20 However, because of their specific system model, the solution cannot be used in general heterogeneous networks with arbitrary number of tiers. Shen and Lok 14 have focused on a two-tier network and do not consider co-tier interference between macro BSs.…”

Tier‐aware joint subchannel and power allocation in uplink OFDMA heterogeneous networks

“…Subchannel allocation: When the transmit power levels of all FUEs are given, each FBS assigns each subchannel to the best user on that subchannel, similar to the works of Ngo et al 9 and Zhang et al 12 In each femtocell, the FUE that achieves the highest SINR on that subchannel is the best user. In doing so, FBS k calculates the power level of each FUE i ∈  k on all subchannels by using the OPC power updating algorithm given by (20), and then computes the SINR of each FUE i ∈  k on all subchannels. Therefore, each FBS k assigns each subchannel to the best user on that subchannel by using (24) as follows:…”

“…In the work of Sun et al, uplink interference mitigation for the OFDMA‐based femtocell networks is performed by dividing the whole spectrum into two parts, a dedicated part for macrocell user equipments(MUEs) and a shared part for both MUEs and femtocell user equipments (FUEs). The cochannel and co‐tier interference avoidance and physical resource block allocation for the OFDMA‐based femtocell networks was studied in the work of Liang et al The joint access control and subchannel allocation problem in a two‐tier HetNet is formulated as an mixed‐integer nonlinear programming (MINLP) problem in the work of Jiang et al In the work of Shgluof et al, cluster‐based and graph‐based resource allocation schemes have been studied.…”

Joint Cell Association and Resource Scheduling for Multi-cell HetNets

“…In [11], each user selects an appropriate BS based on the information transmitted from all BSs. In [8], each user associates with a BS that has the best received power first, and then moves a better BS that increases the system capacity when it moves to that BS. Due to the characteristics of the distributed algorithm, these algorithms have low complexity, but they cannot guarantee to find the optimal cell association and need a lot of overhead to transmit control information.…”

“…[15,4] proposed the sum-utility maximization algorithm for adjusting the ABS ratio and cell association based on the average capacity of each user. Distributed algorithms for cell association was proposed in [11,8]. In [11], each user selects an appropriate BS based on the information transmitted from all BSs.…”