1. Introduction
Particle filters [1] are used in state estimation, where the underlying state-space models can be nonlinear and non-Gaussian. They use a large number of weighted samples, called particles, to represent probability distributions involved in the estimation. Because particle filters do not approximate the nonlinearities in the state-space systems, they are computationally complex. Hence, some particle filter applications require real-time hardware implementations that must be efficient in speed, accuracy, and power consumed.