Reconfigurable Adaptive Channel Sensing

Channel sensing consists of probing the channel from time to time to check whether or not it is active—say, because of an incoming message. When communication is sparse with information being sent once in a long while, channel sensing becomes a significant source of energy consumption. How to reliably detect messages while minimizing the receiver energy consumption? This paper addresses this problem through a reconfigurable scheme, referred to as AdaSense, which exploits the dependency between the receiver noise figure (i.e., the receiver added noise) and the receiver power consumption; a higher power typically translates into less noisy channel observations. AdaSense begins in a low power low reliability mode and makes a first tentative decision based on a few channel observations. If a message is declared, it switches to a high power high reliability mode to confirm the decision, else it sleeps for the entire duration of the second phase. Compared to prominent detection schemes such as the BMAC protocol, AdaSense provides relative energy gains that grow unbounded in the small probability of falsealarm regime, as communication gets sparser. In the non-asymptotic regime energy gains are 30% to 75% for communication scenarios typically found in the context of wake-up receivers.