Performance Analysis of Energy Detection for MIMO Decision Fusion in Wireless Sensor Networks over Arbitrary Fading Channels

In this paper, we consider a wireless sensor network (WSN) with sensors simultaneously reporting their decision to a fusion center (FC) equipped with multiple antennas. A Gaussian mixture channel model is used to obtain a general fading characterization of the channels ensemble between the sensors and the FC. Energy detection is studied as an appealing low-complexity sub-optimal alternative to the (computationally expensive) optimal test based on log-likelihood ratio. Closed-form theoretical performance is obtained for the energy test and furthermore asymptotic analysis for both tests is derived in order to provide a detailed characterization of large-system scenarios. Finally, the simulation results are provided to confirm the theoretical results and compare performance trends of the two tests.