LTE Transmission in Unlicensed Bands: Evaluating the Impact over Clear Channel Assessment

Among the significant advances in mobile network technology, as evident in the latest 3GPP releases, one of the most notable is the possibility to do aggregation between licensed and unlicensed carriers. With LTE transmitting over unlicensed bands, obvious concerns of a fair co- existence with other preexisting technologies have risen up. In this study, we aim to evaluate the impact of LTE transmission on the key mechanism of Clear Channel Assessment (CCA), which is common to several unlicensed systems, amongst which Wi-Fi is the most notable. Relying on the statistical tool of stochastic geometry and a semianalytical approach, we will obtain the probabilities of Wi-Fi preamble false alarm and detection under a wide set of realistic propagation effects, such as path-loss and Rayleigh distributed fading. Above all, we will model the effect of a single LTE downlink interfering transmission, as well as the aggregate interference effect. Hence, we shall be able to evaluate the modified energy detection threshold that has been long debated between 3GPP and IEEE 802.11 Working Groups.

[1]  Jian Liu,et al.  Improved energy detection with interference cancellation in heterogeneous cognitive wireless networks , 2012, 2012 IEEE Global Communications Conference (GLOBECOM).

[2]  A. Giorgetti,et al.  The impact of OFDM interference on TH-PPM/BPAM transmission systems , 2005, IEEE Vehicular Technology Conference.

[3]  Mikko A. Uusitalo,et al.  System performance of LTE and IEEE 802.11 coexisting on a shared frequency band , 2013, 2013 IEEE Wireless Communications and Networking Conference (WCNC).

[4]  Mohamed-Slim Alouini,et al.  Modeling and Analysis of Cellular Networks Using Stochastic Geometry: A Tutorial , 2016, IEEE Communications Surveys & Tutorials.

[5]  Satoshi Nagata,et al.  Licensed-Assisted Access to Unlicensed Spectrum in LTE Release 13 , 2016, IEEE Communications Magazine.

[6]  R. Davies.  Numerical inversion of a characteristic function , 1973 .

[7]  Mohamed-Slim Alouini,et al.  On the Energy Detection of Unknown Signals Over Fading Channels , 2007, IEEE Transactions on Communications.

[8]  Hyundong Shin,et al.  Cognitive Network Interference , 2011, IEEE Journal on Selected Areas in Communications.

[9]  Stefania Sesia,et al.  LTE - The UMTS Long Term Evolution, Second Edition , 2011 .

[10]  R.P.F. Hoefel.  IEEE WLANS: 802.11, 802.11e MAC AND 802.11a, 802.11b, 802.11g PHY cross layer link budget model for cell coverage estimation , 2008, 2008 Canadian Conference on Electrical and Computer Engineering.

[11]  A. Rabbachin,et al.  UWB Energy Detection in the Presence of Multiple Narrowband Interferers , 2007, 2007 IEEE International Conference on Ultra-Wideband.

[12]  Yu Yang,et al.  System architecture and coexistence evaluation of licensed-assisted access LTE with IEEE 802.11 , 2015, 2015 IEEE International Conference on Communication Workshop (ICCW).

[13]  Jeffrey G. Andrews,et al.  Stochastic geometry and random graphs for the analysis and design of wireless networks , 2009, IEEE Journal on Selected Areas in Communications.

[14]  Jeffrey G. Andrews,et al.  Modeling and Analyzing the Coexistence of Wi-Fi and LTE in Unlicensed Spectrum , 2015, IEEE Transactions on Wireless Communications.