Performance evaluation of FSO MIMO links in Gamma-Gamma fading with pointing errors

In this paper, we study the equal gain combining (EGC) scheme in free space optical (FSO) multiple-input multiple-output (MIMO) communication systems over the Gamma-Gamma fading channel with pointing errors. The probability density function (PDF) of the Gamma-Gamma fading with pointing errors contains the Meijer-G function, which makes the error analysis of the considered system very difficult (almost undoable). We propose a new power series based representation for the PDF of the Gamma-Gamma fading with pointing errors. The average bit error rate (BER) for the EGC scheme is derived by using the proposed series based expression of the PDF. We also derive the asymptotic BER for the EGC scheme. The effect of pointing errors over the performance of the scheme is analyzed under different scenarios and it is observed that the pointing errors significantly degrade the diversity of the FSO MIMO system; but under strong atmospheric turbulence pointing errors can be neglected.

[1]  Murat Uysal,et al.  Error rate performance analysis of coded free-space optical links over gamma-gamma atmospheric turbulence channels , 2006, IEEE Transactions on Wireless Communications.

[2]  Manav R. Bhatnagar,et al.  Performance Analysis of Decode-and-Forward Relaying in Gamma-Gamma Fading Channels , 2012, IEEE Photonics Technology Letters.

[3]  Siavash M. Alamouti,et al.  A simple transmit diversity technique for wireless communications , 1998, IEEE J. Sel. Areas Commun..

[4]  Manav R. Bhatnagar,et al.  Differential Decoding of SIM DPSK over FSO MIMO Links , 2013, IEEE Communications Letters.

[5]  Manav R. Bhatnagar,et al.  Average BER analysis of relay selection based decode-and-forward cooperative communication over Gamma-Gamma fading FSO links , 2013, 2013 IEEE International Conference on Communications (ICC).

[6]  K. Peppas,et al.  Average Symbol Error Probability of General-Order Rectangular Quadrature Amplitude Modulation of Optical Wireless Communication Systems Over Atmospheric Turbulence Channels , 2010, IEEE/OSA Journal of Optical Communications and Networking.

[7]  Wilfried Gappmair.  Further results on the capacity of free-space optical channels in turbulent atmosphere , 2011, IET Commun..

[8]  Giwan Yoon,et al.  Average Bit-Error Rate of the Alamouti Scheme in Gamma-Gamma Fading Channels , 2011, IEEE Photonics Technology Letters.

[9]  Ranjan K. Mallik,et al.  Performance analysis of MIMO free-space optical systems in gamma-gamma fading , 2009, IEEE Transactions on Communications.

[10]  Albert Guillén i Fàbregas,et al.  Outage probability of the Gaussian MIMO free-space optical channel with PPM , 2009, IEEE Transactions on Communications.

[11]  I. S. Gradshteyn,et al.  Table of Integrals, Series, and Products , 1976 .

[12]  Manav R. Bhatnagar,et al.  On the capacity of decode-and-forward dual-hop free space optical communication systems , 2014, 2014 IEEE Wireless Communications and Networking Conference (WCNC).

[13]  L. Andrews,et al.  Laser Beam Scintillation with Applications , 2001 .

[14]  K. Roach.  Meijer G function representations , 1997, ISSAC.

[15]  A. García-Zambrana,et al.  Asymptotic error-rate analysis of FSO links using transmit laser selection over gamma-gamma atmospheric turbulence channels with pointing errors. , 2012, Optics express.

[16]  Manav R. Bhatnagar,et al.  On the Performance of Alamouti Scheme in Gamma-Gamma Fading FSO Links With Pointing Errors , 2015, IEEE Wireless Communications Letters.

[17]  Xuan Tang,et al.  Multihop Free-Space Optical Communications Over Turbulence Channels with Pointing Errors using Heterodyne Detection , 2014, Journal of Lightwave Technology.

[18]  George K. Karagiannidis,et al.  Optical wireless links with spatial diversity over strong atmospheric turbulence channels , 2009, IEEE Transactions on Wireless Communications.

[19]  Jianhua Lu,et al.  M-PSK and M-QAM BER computation using signal-space concepts , 1999, IEEE Trans. Commun..

[20]  Zabih Ghassemlooy,et al.  BPSK Subcarrier Intensity Modulated Free-Space Optical Communications in Atmospheric Turbulence , 2009, Journal of Lightwave Technology.

[21]  Joseph Lipka,et al.  A Table of Integrals , 2010 .

[22]  Manav R. Bhatnagar,et al.  Average BER Analysis of Differential Modulation in DF Cooperative Communication System over Gamma-Gamma Fading FSO Links , 2012, IEEE Communications Letters.

[23]  Steve Hranilovic,et al.  Diversity Gain and Outage Probability for MIMO Free-Space Optical Links with Misalignment , 2012, IEEE Transactions on Communications.

[24]  Manav R. Bhatnagar.  A One Bit Feedback Based Beamforming Scheme for FSO MISO System Over Gamma-Gamma Fading , 2015, IEEE Transactions on Communications.

[25]  Debbie Kedar,et al.  Urban optical wireless communication networks: the main challenges and possible solutions , 2004, IEEE Communications Magazine.

[26]  Xian Liu,et al.  Free-space optics optimization models for building sway and atmospheric interference using variable wavelength , 2009, IEEE Transactions on Communications.

[27]  Fan Yang,et al.  Free-Space Optical Communication with Nonzero Boresight Pointing Errors , 2014, IEEE Transactions on Communications.