LS FFT-based channel estimators using pilot-embedded data-bearing approach in space-frequency coded MIMO-OFDM systems

Multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) is one prominent communication system for realizing high speed data transmission services. One critical issue for such systems is channel estimation. In this paper, we first develop a pilot-embedded data-bearing (PEDB) approach for joint channel estimation and data detection. Then we propose a least square (LS) FFT-based channel estimator by employing the concept of FFT-based channel estimation to improve the performance of the PEDB-LS channel estimation. Also, the effects of model mismatch error when considering non-integer multipath delay profiles, and its performance are investigated. We further propose an adaptive LS FFT-based channel estimator that employs the optimum number of significant taps. Simulation results reveal that the adaptive LS FFT-based estimator provides superior performance under quasi-static channels or low Doppler´s shift regimes