A Study on Linear Channel Estimation and Updating Channel State Information for OFDM System in High-Speed Train Environment

This paper focuses on “effective channel estimations for OFDM wireless communication system in high speed train environment.” Because of multi-path interference and Doppler effect, wireless communication signals are interfered and hard to be transmitted. Although there are the existence of line of sight and fewer delay paths in high speed train environment to improve the situation, we still have to use more known signals to estimate the channel state correctly, which will lower the transmission efficiency. In this paper, we will discuss some methods to improve this situation. We first use traditional linear channel estimation to figure out how many known signals are in use, and how much space do we need to set for the pilots in high mobility environment. Then, we use the method of updating channel state information to achieve lower bit error rate and higher transmission efficiency in high mobility environment. In order to improve the transmission efficiency, we also try many kinds of methods to solve the problems under different situations to achieve our goal. Finally, we compare each method of channel estimation by simulation, and we propose some ways that we can further improve the system in the future.