Pilot based time delay estimation for KSP-OFDM systems in a multipath fading environment

We propose two time delay estimators for known symbol padding (KSP) orthogonal frequency division multiplexing (OFDM) in a multipath fading environment. Both estimators make use of pilot symbols in the guard interval and known pilot carriers and take the frequency selectivity of the channel into account. The performance of the estimators is illustrated by means of simulation results for the mean squared error (MSE) and the bit error rate (BER). There is a degradation in performance compared with a receiver with perfect synchronization, especially for high Es/N0, but KSP-OFDM systems with the proposed estimators outperform a cyclic prefix OFDM system with the time delay estimator from [1].