Combination of spatial diversity receiving technology of wireless optical communication in weak turbulence atmosphere channel

LIU Yang; ZHANG Guoan

doi:10.7510/jgjs.issn.1001-3806.2014.05.026

In order to overcome the channel fade effect caused by the atmospheric turbulence, the free space optical (FSO) system model with spatial diversity was analyzed based on intensity detection pulse position modulation (PPM) in weak turbulence atmosphere. The calculating formula of slot error rate (SER) of the system without diversity was derived under PPM firstly. Then as a benchmark, under the case of independent and identical distribution, the average slot error rates of three linear combining technologies, i.e., the maximal ratio combing (MRC), equal gain combining (EGC) and selection combining (SC) were compared by means of numerical simulation. The results show that the improvement of system by MRC is the best, followed by EGC and SC is poor. However, SC is simpler and more convenient. The technology of spatial diversity receiver combination is efficient to improve the performance of FSO and has strong ability of resistance to atmospheric channel fade, and is suited for optical wireless communications systems.

Combination of spatial diversity receiving technology of wireless optical communication in weak turbulence atmosphere channel

Corresponding author: ZHANG Guoan, gzhang@ntu.edu.cn

1. School of Electronics and Information, Nantong University, Nantong 226019, China

Received Date: 2013-10-30

Accepted Date: 2013-11-07

Available Online: 2014-09-25

Abstract: In order to overcome the channel fade effect caused by the atmospheric turbulence, the free space optical (FSO) system model with spatial diversity was analyzed based on intensity detection pulse position modulation (PPM) in weak turbulence atmosphere. The calculating formula of slot error rate (SER) of the system without diversity was derived under PPM firstly. Then as a benchmark, under the case of independent and identical distribution, the average slot error rates of three linear combining technologies, i.e., the maximal ratio combing (MRC), equal gain combining (EGC) and selection combining (SC) were compared by means of numerical simulation. The results show that the improvement of system by MRC is the best, followed by EGC and SC is poor. However, SC is simpler and more convenient. The technology of spatial diversity receiver combination is efficient to improve the performance of FSO and has strong ability of resistance to atmospheric channel fade, and is suited for optical wireless communications systems.

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Reference (14)

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Combination of spatial diversity receiving technology of wireless optical communication in weak turbulence atmosphere channel

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