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.

Radha Krishna Ganti

Department of Electrical Engineering

Anilesh K. Krishnaswamy

Communication

CELL EDGES

Cellular network

Multi-user

Rate expression

RECEIVER ANTENNAS

SPATIAL MULTIPLEXING

ZERO FORCING RECEIVERS

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

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

IEEE International Conference on Communications

It has recently been observed that the SIR distributions of a variety of cellular network models and transmission techniques look very similar in shape. As a result, they are well approximated by a simple horizontal shift (or gain) of the distribution of the most tractable model, the Poisson point process (PPP). To study and explain this behavior, this paper focuses on general single-tier network models with nearest-base station association and studies the asymptotic gain both at 0 and at infinity. We show that the gain at 0 is determined by the so-called mean interference-to-signal ratio (MISR) between the PPP and the network model under consideration, while the gain at infinity is determined by the expected fading-to-interference ratio (EFIR). The analysis of the MISR is based on a novel type of point process, the so-called relative distance process, which is a one-dimensional point process on the unit interval [0,1] that fully determines the SIR. A comparison of the gains at 0 and infinity shows that the gain at 0 indeed provides an excellent approximation for the entire SIR distribution. Moreover, the gain is mostly a function of the network geometry and barely depends on the path loss exponent and the fading. The results are illustrated using several examples of repulsive point processes. © 2015 IEEE.

Fulltext

IEEE Transactions on Wireless Communications

Asymptotics and Approximation of the SIR Distribution in General Cellular Networks

This paper characterizes the performance of cellular networks employing multiple antenna open-loop spatial multiplexing (SM) techniques. We use a stochastic geometric framework to model distance depended inter cell interference. Using this framework, we analyze the coverage and rate using two linear receivers, namely, partial zero-forcing (PZF) and minimum-mean-square-estimation (MMSE) receivers. Analytical expressions are obtained for coverage and rate distribution that are suitable for fast numerical computation. In the case of the PZF receiver, we show that it is not optimal to utilize all the receive antenna for canceling interference.With á as the path loss exponent, Nt transmit antenna, Nr receive antenna, we show that it is optimal to use Nt [1-2/α )(Nr/Nt-1/2 receive antennas for interference cancellation and the remaining antennas for signal enhancement (array gain). For both PZF and MMSE receivers, we observe that increasing the number of data streams provides an improvement in the mean data rate with diminishing returns. Also transmitting Nr streams is not optimal in terms of the mean sum rate. We observe that increasing the SM rate with a PZF receiver always degrades the cell edge data rate while the performance with MMSE receiver is nearly independent of the SM rate. © 2016 IEEE.

Performance of PZF and MMSE Receivers in Cellular Networks with Multi-User Spatial Multiplexing

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.

2014 IEEE Global Communications Conference, GLOBECOM 2014

Spatial multiplexing in heterogeneous networks with MMSE receiver

This paper analyzes the cell edge mobile user performance in the downlink cellular system. We develop frame-work for coverage probability and spectral efficiency. In particular, we analyzed the performance of multi-antenna mobile users under multi-antenna base stations (BSs). The expressions of coverage probability and spectral efficiency are derived for cell edge user using stochastic geometry. We investigate how much the performance of cell edge user is improved when distances connecting BSs and cell edge users are modeled with cell edge null probability distribution. The probability of coverage and spectral efficiency is studied using zero-forcing beam-forming and the performance metrics are compared between coordinated scheduling (CS) and without coordinated scheduling (w/o CS). The interesting observation from our results is that the edge user coverage and rate is closely approaching towards the inner cell typical mobile user's rate and coverage, and the performance is verified with relative probability of coverage gain analysis.

Journal of Circuits, Systems and Computers

Enhancing Coverage and Rate of Cell Edge User in Multi-Antenna Poisson Voronoi Cells

Wiley Series in Probability and Statistics

Stochastic Geometry and its Applications

IEEE Transactions on Information Theory

Transmission Capacity of Ad-hoc Networks With Multiple Antennas Using Transmit Stream Adaptation and Interference Cancellation

IEEE Transactions on Communications

A Tractable Approach to Coverage and Rate in Cellular Networks

Multi-Antenna Communication in Ad Hoc Networks: Achieving MIMO Gains with SIMO Transmission

Open-Loop Spatial Multiplexing and Diversity Communications in Ad Hoc Networks

Journal	Data powered by TypesetIEEE International Conference on Communications
Publisher	Data powered by TypesetInstitute of Electrical and Electronics Engineers Inc.
ISSN	15503607
Open Access	No