Generation Path-Switching in Sequential Monte-Carlo Methods

Traditional sequential Monte-Carlo methods suffer from weight degeneracy which is where the number of distinct particles collapse. This is a particularly debilitating problem in many practical applications. A new method, the adaptive path particle filter, based on the generation gap concept from evolutionary computation, is proposed for recursive Bayesian estimation of non-linear non-Gaussian dynamical systems. A generation-based path evaluation step is embedded into the general sequential importance resampling algorithm leveraging the descriptive ability of discarded particles. A simulation example of the stochastic volatility problem is presented. In this simulation, the adaptive path particle filter is greatly superior to the standard particle filter and the Markov chain Monte-Carlo particle filter. We present a detailed analysis of the results, and suggest directions for future research.