Adaptive Pilot-Embedded Data-Bearing Approach Channel Estimation in Space-Frequency Coded MIMO-OFDM Systems

In this paper, we study the effects of model mismatch error inherently in the FFT-based channel estimation approach when considering the multipath delay profiles with non-integer delays. We propose an adaptive FFT-based channel estimator that employs the optimum number of significant taps such that the average total energy of the channels dissipating in each tap is completely captured in order to compensate the model mismatch error. Furthermore, our proposed pilot-embedded data-bearing approach is employed for joint channel estimation and data detection. Simulation results reveal that the adaptive FFT-based channel estimator is superior to the FFT-based and LS channel estimators; however, in nonquasi-static fading channels under high Doppler´s shift regimes, the performances of all three channel estimators are quite close resulting from the influence of the channel mismatch error that dominates all factors causing the detection error