Simplified MAP Estimator for OFDM Systems Under Fading

This paper presents a simplified maximum a posteriori (MAP) estimator, which yields channel taps in OFDM systems under fading conditions using a parametric correlation model, assuming that the channel is frequency selective, slowly time varying and Gaussian. Expressions for the variance of estimation error are derived to evaluate the performance of the MAP estimator. The relation between the correlation of subchannels taps and error variance and the effect of signal to noise ratio (SNR) are investigated. The performance of the simplified MAP estimator is analyzed using measured channel data. Approximations are developed in order to make the MAP estimator practical. The simulations show that the proposed estimator operates satisfactorily.