In this paper, we analyze the downlink of a multi-antenna heterogeneous cellular network with distance-dependent interference. In particular, we consider open-loop spatial multiplexing (SM) with minimum mean-square estimation (MMSE) receiver for suppressing self-interference as well as other cell interference. Coverage probability and rate distribution are obtained with biased user association rule and inter-cell interference. The results show that using full rate SM at the macro base stations (BSs) degrades the data rate for a large percentage of cell-edge users compared to a low rate SM transmission. Therefore, the cell edge data rate can be improved substantially by reducing the SM rate at the macro BSs while maintaining full SM rate at the pico BSs. The loss in mean spectrum efficiency (SE) caused by the SM rate reduction is shown to be acceptable for the cases of interest. © 2014 IEEE.

Radha Krishna Ganti

Department of Electrical Engineering

Cells

Heterogeneous networks

Mobile security

Probability distributions

COVERAGE PROBABILITIES

Heterogeneous cellular networks

INTERCELL INTERFERENCE

MINIMUM MEAN SQUARE ESTIMATION

OTHER-CELL INTERFERENCE

SELF-INTERFERENCES

SPATIAL MULTIPLEXING

SPECTRUM EFFICIENCY

Multiplexing

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Spatial multiplexing in heterogeneous networks with MMSE receiver

2014 IEEE Global Communications Conference, GLOBECOM 2014

Random spatial models are attractive for modeling heterogeneous cellular networks (HCNs) due to their realism, tractability, and scalability. A major limitation of such models to date in the context of HCNs is the neglect of network traffic and load: all base stations (BSs) have typically been assumed to always be transmitting. Small cells in particular will have a lighter load than macrocells, and so their contribution to the network interference may be significantly overstated in a fully loaded model. This paper incorporates a flexible notion of BS load by introducing a new idea of conditionally thinning the interference field. For a K-tier HCN where BSs across tiers differ in terms of transmit power, supported data rate, deployment density, and now load, we derive the coverage probability for a typical mobile, which connects to the strongest BS signal. Conditioned on this connection, the interfering BSs of the i^{th} tier are assumed to transmit independently with probability p-i, which models the load. Assuming-reasonably-that smaller cells are more lightly loaded than macrocells, the analysis shows that adding such access points to the network always increases the coverage probability. We also observe that fully loaded models are quite pessimistic in terms of coverage. © 2002-2012 IEEE.

Fulltext

IEEE Transactions on Wireless Communications

Load-aware modeling and analysis of heterogeneous cellular networks

In this paper we consider a multi-user spatial multiplexing (SM) cellular network, where Nt streams are transmitted to Nt users in the cell. Specifically, we obtain the coverage and rate expressions for a system employing zero-forcing (ZF) receiver. Compared to single stream transmission (SST), it is interesting to see that SM degrades the rate for a notable percentage of users. For the case of two and four receiver antennas, the increase in mean rate of SM is modest compared to single stream transmission (SST) while SST provides a gain over SM for cell edge users. © 2013 IEEE.

IEEE International Conference on Communications

Coverage and rate in cellular networks with multi-user spatial multiplexing

Cellular networks are in a major transition from a carefully planned set of large tower-mounted base-stations (BSs) to an irregular deployment of heterogeneous infrastructure elements that often additionally includes micro, pico, and femtocells, as well as distributed antennas. In this paper, we develop a tractable, flexible, and accurate model for a downlink heterogeneous cellular network (HCN) consisting of K tiers of randomly located BSs, where each tier may differ in terms of average transmit power, supported data rate and BS density. Assuming a mobile user connects to the strongest candidate BS, the resulting Signal-to-Interference-plus-Noise-Ratio (SINR) is greater than 1 when in coverage, Rayleigh fading, we derive an expression for the probability of coverage (equivalently outage) over the entire network under both open and closed access, which assumes a strikingly simple closed-form in the high SINR regime and is accurate down to -4 dB even under weaker assumptions. For external validation, we compare against an actual LTE network (for tier 1) with the other K-1 tiers being modeled as independent Poisson Point Processes. In this case as well, our model is accurate to within 1-2 dB. We also derive the average rate achieved by a randomly located mobile and the average load on each tier of BSs. One interesting observation for interference-limited open access networks is that at a given SINR, adding more tiers and/or BSs neither increases nor decreases the probability of coverage or outage when all the tiers have the same target-SINR. &copy; 2006 IEEE.

IEEE Journal on Selected Areas in Communications

Modeling and analysis of K-tier downlink heterogeneous cellular networks

IEEE Transactions on Vehicular Technology

Exploiting Spatial Interference Alignment and Opportunistic Scheduling in the Downlink of Interference-Limited Systems

Downlink MIMO HetNets: Modeling, Ordering Results and Performance Analysis

Journal	Data powered by Typeset2014 IEEE Global Communications Conference, GLOBECOM 2014
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers Inc.
Open Access	No