Coverage Analysis for Millimeter Wave Cellular Networks With Imperfect Beam Alignment

Millimeter wave (mmWave) communications is a promising approach to satisfy the increasing high data rate requirement of next generation mobile communications. This paper studies the downlink coverage performance of mmWave cellular networks with imperfect beam alignment. An enhanced antenna model is adopted to model the directional antenna beamforming pattern, in which the mainlobe beamwidth and directivity gain can be expressed as functions of the number of elements in the antenna array. After deriving the probability density function of the distance between mobile station and its serving base station (BS), the directivity gain with imperfect beam alignment is obtained as a discrete random variable. Then, a computationally tractable expression is obtained for the coverage probability of mmWave cellular networks. This generalized expression can be applied in different blockage regimes, e.g., general blockage regime, full-blockage regime, and nonblockage regime with or without beam alignment errors. Numerical results show that small beam alignment errors will not deteriorate the coverage performance significantly, and the antenna array with the less number of elements provides higher robustness against the beam alignment errors. Moreover, when the beam alignment error is small enough, the coverage performance can be improved by increasing the BS intensity and the number of elements in the antenna array.

[1]  Martin Haenggi,et al.  Coverage Analysis for Millimeter Wave Networks: The Impact of Directional Antenna Arrays , 2017, IEEE Journal on Selected Areas in Communications.

[2]  Jeffrey G. Andrews,et al.  A Tractable Approach to Coverage and Rate in Cellular Networks , 2010, IEEE Transactions on Communications.

[3]  Theodore S. Rappaport,et al.  Millimeter Wave Mobile Communications for 5G Cellular: It Will Work! , 2013, IEEE Access.

[4]  Zhouyue Pi,et al.  An introduction to millimeter-wave mobile broadband systems , 2011, IEEE Communications Magazine.

[5]  Theodore S. Rappaport,et al.  Broadband Millimeter-Wave Propagation Measurements and Models Using Adaptive-Beam Antennas for Outdoor Urban Cellular Communications , 2013, IEEE Transactions on Antennas and Propagation.

[6]  Robert W. Heath,et al.  Auxiliary Beam Pair Enabled AoD and AoA Estimation in Closed-Loop Large-Scale Millimeter-Wave MIMO Systems , 2017, IEEE Transactions on Wireless Communications.

[7]  Robert W. Heath,et al.  Analysis of Blockage Effects on Urban Cellular Networks , 2013, IEEE Transactions on Wireless Communications.

[8]  Xiqi Gao,et al.  Cellular architecture and key technologies for 5G wireless communication networks , 2014, IEEE Communications Magazine.

[9]  Jeffrey G. Andrews,et al.  Modeling and Analyzing Millimeter Wave Cellular Systems , 2016, IEEE Transactions on Communications.

[10]  Taoka Hidekazu,et al.  Scenarios for 5G mobile and wireless communications: the vision of the METIS project , 2014, IEEE Communications Magazine.

[11]  Jeffrey G. Andrews,et al.  Transmission capacity of ad hoc networks with spatial diversity , 2007, IEEE Transactions on Wireless Communications.

[12]  Jeffrey G. Andrews,et al.  Downlink and Uplink Cell Association With Traditional Macrocells and Millimeter Wave Small Cells , 2016, IEEE Transactions on Wireless Communications.

[13]  Sridhar Rajagopal,et al.  Channel Feasibility for Outdoor Non-Line-of-Sight mmWave Mobile Communication , 2012, 2012 IEEE Vehicular Technology Conference (VTC Fall).

[14]  Andrea J. Goldsmith,et al.  Rainfall Effect on the Performance of Millimeter-Wave MIMO Systems , 2015, IEEE Transactions on Wireless Communications.

[15]  Daniela Tuninetti,et al.  Coverage in mmWave Cellular Networks With Base Station Co-Operation , 2015, IEEE Transactions on Wireless Communications.

[16]  Ashwin Sampath,et al.  Beamforming Tradeoffs for Initial UE Discovery in Millimeter-Wave MIMO Systems , 2016, IEEE Journal of Selected Topics in Signal Processing.

[17]  Robert W. Heath,et al.  Wireless Powered Dense Cellular Networks: How Many Small Cells Do We Need? , 2017, IEEE Journal on Selected Areas in Communications.

[18]  Andreas F. Molisch,et al.  Performance evaluation of CDMA reverse links with imperfect beamforming in a multicell environment using a simplified beamforming model , 2006, IEEE Transactions on Vehicular Technology.

[19]  Jeffrey G. Andrews,et al.  What Will 5G Be? , 2014, IEEE Journal on Selected Areas in Communications.

[20]  Xiang-Gen Xia,et al.  Coverage Analysis for Millimeter Wave Cellular Networks with Beam Alignment Errors , 2017, 2017 IEEE Globecom Workshops (GC Wkshps).

[21]  Robert W. Heath,et al.  Secure Communications in Millimeter Wave Ad Hoc Networks , 2016, IEEE Transactions on Wireless Communications.

[22]  Sayandev Mukherjee Analytical Modeling of Heterogeneous Cellular Networks: Geometry, Coverage, and Capacity , 2013 .

[23]  Robert W. Heath,et al.  Performance Analysis of Outdoor mmWave Ad Hoc Networks , 2014, IEEE Transactions on Signal Processing.

[24]  Horst Alzer,et al.  On some inequalities for the incomplete gamma function , 1997, Math. Comput..

[25]  Marco Di Renzo,et al.  Stochastic Geometry Modeling and Analysis of Multi-Tier Millimeter Wave Cellular Networks , 2014, IEEE Transactions on Wireless Communications.

[26]  Jeffrey G. Andrews,et al.  Tractable Model for Rate in Self-Backhauled Millimeter Wave Cellular Networks , 2014, IEEE Journal on Selected Areas in Communications.

[27]  Robert W. Heath,et al.  Ergodic capacity in mmWave ad hoc network with imperfect beam alignment , 2015, MILCOM 2015 - 2015 IEEE Military Communications Conference.

[28]  Theodore S. Rappaport,et al.  Millimeter Wave Channel Modeling and Cellular Capacity Evaluation , 2013, IEEE Journal on Selected Areas in Communications.

[29]  François Baccelli,et al.  Stochastic geometry and wireless networks , 2009 .

[30]  A. Lozano,et al.  What Will 5 G Be ? , 2014 .

[31]  Robert W. Heath,et al.  Coverage and Rate Analysis for Millimeter-Wave Cellular Networks , 2014, IEEE Transactions on Wireless Communications.