Analysis and compensation of channel correction in pilot-aided OFDM systems with symbol timing offset

Symbol timing offset (STO) can cause phase shift proportional to the subcarrier index at the FFT output of an OFDM receiver. For the OFDM systems that channel estimation is performed symbol by symbol, the rotated phase can be compensated by channel equalization so that only a coarse STO estimation for shifting the FFT window to avoid intersymbol interference is enough. But a large number of shift samples will deteriorate the subcarrier channels requiring interpolation from pilot subcarriers. In this paper we analyze the effect of STO on channel interpolation and propose a compensation factor for channel correction. The new technique resists to the variation of residual STO estimation so that a simple residual STO estimation method can be used with low complexity.