Cramer-Rao bound for blind, semi-blind and non-blind channel estimation in OFDM systems

In the estimation theory, the Cramer-Rao bound (CRB) is a very powerful theory tool. In this paper, based on the matrix formulation of OFDM signals, the CRB for blind, semi-blind and non-blind channel estimation in OFDM systems is derived. We simulate the performance of the channel estimation in two different OFDM systems such as CP-OFDM and ZP-OFDM. In the simulations, we validate the correctness of the CRB and evaluate some channel estimation methods by using the CRB.