Particle swarm enhanced graph-based iterative receiver with phase noise and frequency offset

In this paper, an improved message passing approach for iterative receiver is proposed using particle swarm optimized (PSO) particle filter (PF) over channels affected by phase noise and carrier frequency offset (CFO). The sum-product algorithm (SPA) is employed on the factor graph that represents the joint posterior distribution of the information symbols and the unknown parameters. A new sequential updating scheme is developed for continuous density propagation on factor graph using particle filters. To overcome the particle degeneracy and impoverishment problem, PSO scheme is incorporated into particle updating procedure to move the particles to higher likelihood area and then obtain the better approximation of the true posterior probability density function. Numerical results demonstrate the effectiveness of the proposed PSO-PF based algorithm for the graph-based iterative receiver.