On the Design of an Elegant CFO Estimate System with the Assistance of Pilots for OFDM Transmission

Abstract

We present an improved line search method of the carrier frequency offset (CFO) estimate technique for OFDM systems aided with pilots. Unlike the conventional approaches, prior knowledge of channel order is unnecessary for the presented scheme, because we apply an interpolation technique for obtaining the extended channel frequency response. The search mechanism of the proposed approach is primarily based on the criterion that CFO can be found by discovering the frequency that achieves the minimum value of the well-defined channel residual energy. In addition, we substitute the line search method with an iterative approach to reduce the proposed estimator's complexity. Analytical and simulation results have been conducted to verify the efficacy of the proposed schemes in this paper.

A Haar Wavelet Decision Feedback Channel Estimation Method in OFDM Systems

“…median(·) is the operation of obtaining the mid-value of a vector. In [16], constant value 0.6745 is used as the denominator in Equation (9). The channel environment used in this paper is different from the paper [16].…”

“…To estimate the characteristics of the channel, some conventional channel estimation methods are often performed in frequency-domain using pilots [9], such as least square (LS) method [10][11][12], minimum mean square error (MMSE) method [13], linear MMSE (LMMSE) method [14], singular value decomposition (SVD) method [15], noise suppression threshold method [16,17], and so on. The LS channel estimation method has the advantage of low complexity and easy implementation.…”