Channel estimation based on pilot tones for OFDM on time-varying channel

The orthogonal frequency division multiplexing (OFDM) is one of the most promising techniques for high speed wireless data communication. OFDM can provide high data rates with sufficient robustness to radio channel impairments. In this paper, the time-varying channel estimation methods based oil pilot tones in OFDM systems are investigated. The mobile channel is time-varying and frequency selective and we must take into account the channel interference due to Doppler shift, so we adopt grouped pilot pattern and low-pass interpolation methods to estimate the channel impulse response (CIR). The simulation result shows that grouped pilot pattern can achieve low bit error rate (BER) than other traditional methods. Compared with linear interpolation, the interpolation method proposed in this paper has better performance in OFDM systems with high Doppler shift.