Frequency-domain interpolation-based channel estimation in pilot-aided OFDM systems

We propose a novel frequency-domain interpolation algorithm for channel estimation in comb-type pilot-aided orthogonal frequency-division multiplexing (OFDM) systems. There exist two major types of pilot-aided OFDM channel estimation methods: time-domain and frequency-domain. We show that these two estimation methods have mathematical equivalence. The performance of these channel estimators mainly depends on how the channel impulse response (CIR) is reconstructed from the frequency-domain channel response sample at the pilot sub-carriers. By closely examining time-domain CIR characteristics, we propose a new frequency-domain interpolation-based algorithm that can overcome the limitation of conventional frequency-domain algorithms. Meanwhile, this new algorithm has the advantages of less latency and computation complexity when compared to time-domain approaches. Simulation results show that the proposed algorithm outperforms frequency-domain interpolation-based and time-domain algorithms in most cases.