A New Delay-Doppler-Based Pilot Scheme for OFDM Systems

The orthogonal frequency division multiplexing (OFDM) waveform presents some limitations in time-varying channels, experienced e.g., in high-mobility environment. In this paper, we introduce a new channel estimation approach to enhance OFDM system performance in high-Doppler channels. This novel approach consists in inserting a pilot in the delay-Doppler domain, without puncturing the data in the frequency-time domain. Therefore, it avoids pilot overhead when the channel is very selective. Simulation results show that the proposed method outperforms the standard techniques by achieving a higher data throughput in high-mobility scenarios.