Joint Carrier Frequency Offset and Channel Estimation for Uplink MIMO-OFDMA Systems Using Parallel Schmidt Rao-Blackwellized Particle Filters
Joint Carrier Frequency Offset (CFO) and channel estimation for uplink MIMO-OFDMA systems over time-varying channels is investigated. To cope with the prohibitive computational complexity involved in estimating multiple CFOs and channels, pilot-assisted and semi-blind schemes comprised of parallel Schmidt Extended Kalman Filters (SEKFs) and Schmidt-Kalman Approximate Particle Filters (SK-APF) are proposed. In the SK-APF, a Rao-Blackwellized Particle Filter (RBPF) is developed to first estimate the nonlinear state variable, i.e. the desired user's CFO, through the Sampling-Importance-ReSampling (SIRS) technique.