Joint channel and frequency offset estimation for OFDM systems

In this paper, a joint channel and frequency offset estimation algorithm is proposed. The time variation of the effective channel impulse response (CIR) due to frequency offset is tracked using a channel tracker. This variation is used to estimate the frequency offset as well as the actual time-invariant channel coefficients. The proposed method does not require transmission of repetitive pattern, thus allowing a covert communication for applications where security is important. It can be used to estimate not only the fractional part but also the integer part of the frequency offset, The proposed algorithm is tested using computer simulations. It is observed that it has performance close to the Cramer-Rao lower bound.