Effect of Mutual Coupling on the Energy Requirement of MIMO-Based Wireless Sensor Networks

A theoretical model was developed to estimate effect of the mutual coupling on the energy requirement of a multiple-input multiple-output (MIMO) based wireless sensor network (WSN). Clustered channel modeling with Rician fading distribution is assumed to include the effect of the line-of-sight (LOS) ray paths. The effect of propagation environments is included in the analysis by assuming a two-slope path loss model. The effect of knowing the channel state information (CSI) in the MIMO system (MIMO _csi) is also included in the analysis. It is shown that the presence of mutual coupling between elements of MIMO array decreases the energy required by the MIMO based WSN. Simulation results also show that it is possible to use a compact circular antenna array with a quarter wavelength diameter to build a MIMO _csi based WSN that requires almost constant energy for applications that cover a range from few meters up to around 100 m.