Uplink capacity and interference avoidance for two-tier femtocell networks

By Vikram Chandrasekhar, Jeffrey G. Andrews. IEEE Transactions on Wireless Communications, 2007

563 citations recorded by the source corpus.

Two-tier femtocell networks- comprising a conventional cellular network plus embedded femtocell hotspots- offer an economically viable solution to achieving high cellular user capacity and improved coverage. With universal frequency reuse and DS-CDMA transmission however, the ensuing cross-tier interference causes unacceptable outage probability. This paper develops an uplink capacity analysis and interference avoidance strategy in such a two-tier CDMA network. We evaluate a network-wide area spectral efficiency metric called the operating contour (OC) defined as the feasible combinations of the average number of active macrocell users and femtocell base stations (BS) per cell-site that satisfy a target outage constraint. The capacity analysis provides an accurate characterization of the uplink outage probability, accounting for power control, path loss and shadowing effects. Considering worst case interference at a corner femtocell, results reveal that interference avoidance through a time-hopped CDMA physical layer and sectorized antennas allows about a 7x higher femtocell density, relative to a split spectrum two-tier network with omnidirectional femtocell antennas. A femtocell exclusion region and a tier selection based handoff policy offers modest improvements in the OCs. These results provide guidelines for the design of robust shared spectrum two-tier networks.

Subfields: Computer Networks and Communications, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/c41b2846972f482781f7143bebf9b66978715732

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Citations in the corpus

Cognitive Network Interference (2011, methodology): “More recently, the Poisson model has been applied for spatial node distributions in a variety of wireless networks such as random access, ad hoc, relay, cognitive radio, or femtocell networks [41]–[52].”
Throughput Optimization, Spectrum Allocation, and Access Control in Two-Tier Femtocell Networks (2012, methodology): “Indeed, PPP has been used to model FAPs' positions in numerous existing research papers on the modeling of FAPs, for example in [15], [26], [27].”
Power control in two-tier femtocell networks (2008, background): “For example, signal strength based power control (channel inversion) employed by cellular users results in unacceptable deterioration of femtocell SINRs [2].”
Femtocell networks: a survey (2008, background): “Over the reverse link in closed access, we suggest providing a higher receive power target to femtocell users relative to macrocell users [9], which will vary based on femtocell location.”
Modeling heterogeneous network interference (2012, methodology): “The problem is compounded by the observation that the deployment of much of the small cell infrastructure will be demand based and more irregular than traditional infrastructure deployments [4].”
Heterogeneous Cellular Networks with Flexible Cell Association: A Comprehensive Downlink SINR Analysis (2011, methodology): “In the interim, the PPP model has been used extensively for modeling unplanned networks such as femtocells [17], [18], [19] or ad hoc networks [20], [21]; and for both it is now fairly well-accepted [22], [23].”
Interference Management in Femtocells (2013, methodology): “SIC [86][87] [88] PIC [89][90][91] MSIC [93] MUD [95] [96] Spectrum Splitting [31][47][49] [97] Power Control [103][109] [111] [112] Time Hopping [99][100] Spectrum Arrangement schemes [104][105] Other Schemes [83][98] [101][107] Distributed Interference Management”
On Stochastic Geometry Modeling of Cellular Uplink Transmission With Truncated Channel Inversion Power Control (2014, methodology): “3 Each of the available stochastic geometry models [15]–[18] approximates the system model in a different way to simplify the analysis and none of them accounts for the maximum transmit power of the UEs.”
Spectrum allocation in tiered cellular networks (2009, background): “The worst-case scenario arises either when a high powered cell edge user causes interference to nearby femtocells[6], or when cell interior femtocell users cause”
Stochastic Geometry for Modeling, Analysis, and Design of Multi-Tier and Cognitive Cellular Wireless Networks: A Survey (2013, methodology): “The system model considered in [70] accounts for sectored antennas, spread spectrum transmission, and power control via channel inversion.”
Modeling and Analysis of K-Tier Downlink Heterogeneous Cellular Networks (2011, background): “Email: rganti@ee.iitm.ac.in. and are distinguished by their end-user installation in arbitrary locations, very short range, and possibility of having a closed-subscriber group [10]–[12].”