Detection performance limits of channel impaired distributed sensor networks

Traditional parallel distributed detection systems assume perfect channels between local sensors and a fusion center. However, for the emerging wireless sensor networks with inexpensive sensors and stringent power/delay constraints, error-free transmission is not guaranteed. In this paper, we study the performance degradation due to imperfect channels between the sensors and the fusion center under both asymptotic and non-asymptotic regimes. For asymptotic analysis, we compute the error exponents of the underlying hypothesis testing problem in the presence of discrete transmission channels; while for cases with a finite number of sensors, we determine channel conditions under which the distributed detection systems become useless -observing the channel output might not help in reducing the error probability performance at the fusion center. Numerical examples are provided to illustrate the concepts.