We present a consensus-based distributed particle filter (PF) for wireless
sensor networks. Each sensor runs a local PF to compute a global state estimate
that takes into account the measurements of all sensors. The local PFs use the
joint (all-sensors) likelihood function, which is calculated in a distributed
way by a novel generalization of the likelihood consensus scheme. A performance
improvement (or a reduction of the required number of particles) is achieved by
a novel distributed, consensus-based method for adapting the proposal densities
of the local PFs.
We consider distributed state estimation in a wireless sensor network without
a fusion center. Each sensor performs a global estimation task - based on the
past and current measurements of all sensors - using only local processing and
local communications with its neighbors. In this task, the joint (all-sensors)
likelihood function (JLF) plays a central role as it epitomizes the
measurements of all sensors. We propose a distributed method for computing an
approximation of the JLF by means of consensus algorithms.