A comparison of pilot-aided channel estimation methods for OFDM systems

This paper deals with the estimation of the channel impulse response (CIR) in orthogonal frequency division multiplexed (OFDM) systems. In particular, we focus on two pilot-aided schemes: the maximum likelihood estimator (MLE ) and the Bayesian minimum mean square error estimator (MMSEE). The advanta ge of the former is that it is simpler to implement as it needs no informat ion on the channel statistics. On the other hand, the MMSEE is expected to have better performance as it exploits prior information about the channel. Theoretical analysis and computer simulations are used in the comparisons. At SNR values of practical interest, the two schemes are found to exhibit n early equal performance, provided that the number of pilot tones is suffici ently greater than the CIRs length. Otherwise, the MMSEE is superior. In an y case, the MMSEE is more complex to implement.