Risk Sensitive Filter for MIMO-OFDM System Channel Estimation using Combined Orthogonal Pilot Approch under Parameter Uncertainty

Abstract

In this paper risk-sensitive filter RSF based channel estimation has been proposed for MIMO-OFDM system The uniqueness of the risk sensitive filter s performance in the presence of uncertainty is explored for channel estimation problem In general the channel estimation problem is formulated as the estimation of time varying coefficients of FIR filter Estimation of channel is very critical task to recover the error free signal at the end of the receiver under the unknown statistics of the channel Several Kalman based algorithms are proposed for channel estimation in MIMO-OFDM system under different channel considerations using traditional pilot based estimation Auto regressive AR model is used to formulate the parameters to be estimated Unlike to the traditional pilot based approach in this work combined orthogonal pilot aided COPA channel estimation is used to eliminate the same frequency interference created by the OFDM frequency among different transmit-receive antenna pairs The results proved that proposed estimator is outperforming when compared with Kalman under uncertainty in parameter