Distributed decision fusion over fading channels in hierarchical wireless sensor networks

In this work, we investigate distributed decision fusion in hierarchical wireless sensor networks that are degraded by fading and noise. With the use of the complete fading channel state information (CSI), we first derive the likelihood ratio test (LRT) based optimum fusion rule, which we call LRT–CSI. Then, we relax the use of the complete CSI and only the exact phase information is employed together with channel envelope statistics (CS), and we develop another LRT based fusion rule named LRT–CS, which is computationally simpler to implement compared to LRT–CSI. Finally, we analyze the detection performance of all the proposed fusion rules through extensive numerical results.