Opportunistic random access for distributed parameter estimation in wireless sensor networks

In this paper, we propose and analyze an opportunistic random access scheme suitable for distributed parameter estimation via wireless sensor networks (WSN). At the fusion center (FC), we assume that a Successive Interference Cancellation (SIC) scheme is available. Consequently, several sensor observations can be sent in parallel to the FC, this resulting into a reduction of the time needed to collect a sufficient number of observations from which the unknown parameter can be estimated with a given accuracy (i.e. lower system latency). Throughout the analysis, we aim to minimize the overall energy consumption, namely, both for the random access and data transmission. To do so, we derive closed form expressions of the energy required for random access and the latency of the system and, also, accurate numerical expressions of the energy spent in data transmission. Computer simulation results reveal a number of interesting trade-offs in terms of overall energy consumption, computational complexity required at the FC and system latency.