Connectivity gain evaluation using diversity in wireless sensor networks under correlated shadowing

In this paper, common diversity techniques are proposed in order to achieve connectivity improvement in wireless sensor networks under correlated shadowing channels. In the operational environment of WSN´s, shadowing is the dominant fading mechanism and has the greatest impact on network´s performance and connectivity. A new model based on Inverse Gaussian and Bivariate Inverse Gaussian distribution is proposed for approximating the statistical behavior of Signal-to-Noise ratio (SNR) for both correlated and uncorrelated shadowing channels. In order to counterbalance the impact of fading, we suggest the use of Selection Combining (SC) diversity reception scheme. Moreover, our analysis is based on the realistic assumption that the corresponding radio links of the diversity branches are considered correlated. Finally, the connectivity gain from the use of diversity is formulated and calculated for several operational parameters.