Parameter Based Channel Estimation for OFDM Systems Over Time-Varying Channels

This paper investigates the parameter-based (PB) channel estimation for orthogonal frequency division multiplexing over time-varying channels. The time-varying channel impulse response (CIR) can be represented using limited number of channel parameters. Instead of estimating the CIR directly, the PB approach estimates these parameters, from which, the CIR can be regenerated. To estimate these parameters, a differential scheme, utilizing the repetitive structure of the training signal, is proposed in this paper. When expressing the received signal in time-frequency-representation form, the repetitive structure can cause a phase difference between consecutive signal branches. This provides the chance for parameter estimation. Space domain sampling using multiple receive antennas are also employed to gain unique solution for parameter estimation. The effectiveness of the proposed algorithm is demonstrated by computer simulations.