Performance analysis of general pilot-aided linear channel estimation in the LTE OFDMA systems with application to simplified MMSE schemes

In this paper we provide a general framework for the performance analysis o pilot-aided linear channel estimators class including the general interpolation, least squares (LS), regularized LS, minimum-mean-squared-error (MMSE) and approximated MMSE estimators. The analysis is performed from the perspective of Long Term Evolution Orthogonal Frequency Division Multiple Access (LTE OFDMA) down-link systems. We also propose two novel modified MMS schemes, an Exponential Mismatched MMSE and a Simplified MMSE, to overcome the high implementation complexity of the MMSE and offering improvements to other known approximated methods. At the end, we verify the analytical results by means of Monte-Carlo simulations in terms of Normalized Mean Square Error (NMSE) and coded Bit Error Rate (BER).