Improvement of ground to satellite fso link performance using transmit diversity in weak atmospheric turbulence

The performance of ground to satellite Free Space Optical (FSO) communication link is degraded due to the presence of atmospheric turbulence that causes fluctuations in both intensity and phase of the received optical signal. In this paper, bit error rate (BER) performance of FSO link using transmit diversity is investigated for coherent (sub-carrier BPSK and sub-carrier QPSK) and non-coherent (OOK and Q-PPM) modulation schemes in weak atmospheric turbulence channel. It is seen that multiple transmitting antennae help to overcome the turbulence induced fading effect. It is observed that sub-carrier BPSK modulation outperforms the other modulation schemes in terms of minimum SNR requirement for a given BER. Among non-coherent modulation schemes, Q-PPM performs better than OOK. However, as the level of Q in Q-PPM increases, its performance degrades and it becomes worse than OOK for certain values of atmospheric turbulence. Also, the effect of correlation among different transmitting antennae beams is analysed on the link performance.

[1]  Jason D. Schmidt,et al.  Anisoplanatism in airborne laser communication. , 2008, Optics express.

[2]  Isaac I. Kim,et al.  Scintillation reduction using multiple transmitters , 1997, Photonics West.

[3]  H. A. Willebrand,et al.  Fiber optics without fiber , 2001 .

[4]  Shane M. Haas,et al.  Capacity of and coding for multiple-aperture, wireless, optical communications , 2006 .

[5]  Larry C. Andrews,et al.  Aperture averaging of optical scintillations: power fluctuations and the temporal spectrum , 2000 .

[6]  Subrat Kar,et al.  Ground-to-Satellite Optical Communication Link Performance with Spatial Diversity in Weak Atmospheric Turbulence , 2010 .

[7]  Etty J. Lee,et al.  Part 1: optical communication over the clear turbulent atmospheric channel using diversity , 2004, IEEE Journal on Selected Areas in Communications.

[8]  Desmond P. Taylor,et al.  Optical Communication Using Subcarrier PSK Intensity Modulation Through Atmospheric Turbulence Channels , 2007, IEEE Transactions on Communications.

[9]  Jia Li,et al.  Optical Communication Using Subcarrier PSK Intensity Modulation Through Atmospheric Turbulence Channels , 2007, IEEE Trans. Commun..

[10]  Joseph M. Kahn,et al.  Free-space optical communication through atmospheric turbulence channels , 2002, IEEE Trans. Commun..

[11]  Akira Ishimaru,et al.  Wave propagation and scattering in random media , 1997 .

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

[13]  Aniceto Belmonte,et al.  Performance of synchronous optical receivers using atmospheric compensation techniques. , 2008, Optics express.

[14]  H. Yura,et al.  Optical scintillation statistics for IR ground-to-space laser communication systems. , 1983, Applied optics.

[15]  Mohamed-Slim Alouini,et al.  Digital Communication over Fading Channels: Simon/Digital Communications 2e , 2004 .

[16]  S. Bourennane,et al.  Fading Reduction by Aperture Averaging and Spatial Diversity in Optical Wireless Systems , 2009, IEEE/OSA Journal of Optical Communications and Networking.

[17]  L C Andrews,et al.  Optical scintillations and fade statistics for a satellite-communication system. , 1995, Applied optics.