Energy-efficient noncoherent signal detection for networked sensors using ordered transmissions

Energy efficiency has been a topic of recent interest in networks employing wireless sensors used for signal detection. Energy efficient signal detection is of particular interest in systems where such sensors carry their own energy sources with a limited capacity. It has been demonstrated that ordering the sensor transmissions and halting them upon accumulating enough evidence can save transmissions (energy) without degrading the systems detection performance. We extend this concept to a system employing noncoherent signal detection where the hypothesis testing problem involves a log-likelihood ratio which can only take on nonnegative values. We propose a new algorithm for ordering the transmissions for such systems and show that the new algorithm tends to provide more significant savings than the existing methods, requiring as little as one sensor transmission in certain cases. We utilize MIMO radar as an example in our paper, and provide results demonstrating the savings achieved.