First, we give an overview of channel estimation in Orthogonal Frequency Division Multiplexing (OFDM) systems, then analyse Discrete Fourier Transform (DFT) algorithm. The received pilot-aided in frequency domain after Least Square (LS) algorithm, is converted to time domain based on Inverse Discrete Fourier Transform (IDFT). Usually, It consider primary channel energy is in the area of the maximum multipath expansion, but there are noise in these area. Also, there are energy leakage by IDFT, due to non-sample-spaced channel. Thus, we propose a method of computing noisy threshold to minish noise, but reserve primary energy path and leaking path. Notice the engineering application, we consider LTE-Advanced systems. The simulation indicates that, performance of using the method of the aboved-mentioned is effective than conventional algorithm.
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