A method for channel estimation in an Orthogonal Frequency Division Multiplexing, OFDM, system, comprising: a. in a transmitter, determining a distribution density of pilot OFDM symbols according to the maximum Doppler frequency shift supported by the system, and transmitting pilot OFDM symbols and data OFDM symbols based on the distribution density of the pilot OFDM symbols; further comprising the steps of: b11. in a receiver, obtaining (1501, 1601) time-domain channel responses of pilot OFDM symbols transmitted by the transmitter on the basis of time-domain signal sequences of the pilot OFDM symbols and frequency-domain signal sequences of the pilot OFDM symbols; b12. extracting (1502, 1602) time-domain channel information of the pilot OFDM symbols from the time-domain channel response of the pilot OFDM symbols; and b13. estimating (1503-1504,1603-1604) frequency-domain channel information of a data OFDM symbol by interpolating the time-domain channel information of the adjacent pilot OFDM symbols; wherein the Step b12 comprises: determining a truncation range according to a time delay spread supported by the system; obtaining time-domain channel values within the truncation range from the time-domain channel response of the pilot OFDM symbols obtained in Step b11; and substituting zero for the time-domain channel values that have been truncated; or determining one or more than one most powerful paths of time-domain channels through analyzing time-domain channel response of pilot OFDM symbols; selecting time-domain channel value corresponding to the determined one or more than one most powerful paths; and substituting zero for the time-domain channel values that have not been selected; or determining a truncation range by analyzing time-domain channel response pilot OFDM symbols; selecting time-domain channel values within the truncation range; and substituting zero for the time-domain channel values that have not been selected. a. in a transmitter, determining a distribution density of pilot OFDM symbols according to the maximum Doppler frequency shift supported by the system, and transmitting pilot OFDM symbols and data OFDM symbols based on the distribution density of the pilot OFDM symbols; further comprising the steps of: b11. in a receiver, obtaining (1501, 1601) time-domain channel responses of pilot OFDM symbols transmitted by the transmitter on the basis of time-domain signal sequences of the pilot OFDM symbols and frequency-domain signal sequences of the pilot OFDM symbols; b12. extracting (1502, 1602) time-domain channel information of the pilot OFDM symbols from the time-domain channel response of the pilot OFDM symbols; and b13. estimating (1503-1504,1603-1604) frequency-domain channel information of a data OFDM symbol by interpolating the time-domain channel information of the adjacent pilot OFDM symbols; wherein the Step b12 comprises: determining a truncation range according to a time delay spread supported by the system; obtaining time-domain channel values within the truncation range from the time-domain channel response of the pilot OFDM symbols obtained in Step b11; and substituting zero for the time-domain channel values that have been truncated; or determining one or more than one most powerful paths of time-domain channels through analyzing time-domain channel response of pilot OFDM symbols; selecting time-domain channel value corresponding to the determined one or more than one most powerful paths; and substituting zero for the time-domain channel values that have not been selected; or determining a truncation range by analyzing time-domain channel response pilot OFDM symbols; selecting time-domain channel values within the truncation range; and substituting zero for the time-domain channel values that have not been selected. b11. in a receiver, obtaining (1501, 1601) time-domain channel responses of pilot OFDM symbols transmitted by the transmitter on the basis of time-domain signal sequences of the pilot OFDM symbols and frequency-domain signal sequences of the pilot OFDM symbols; b12. extracting (1502, 1602) time-domain channel information of the pilot OFDM symbols from the time-domain channel response of the pilot OFDM symbols; and b13. estimating (1503-1504,1603-1604) frequency-domain channel information of a data OFDM symbol by interpolating the time-domain channel information of the adjacent pilot OFDM symbols; determining a truncation range according to a time delay spread supported by the system; obtaining time-domain channel values within the truncation range from the time-domain channel response of the pilot OFDM symbols obtained in Step b11; and substituting zero for the time-domain channel values that have been truncated; or determining one or more than one most powerful paths of time-domain channels through analyzing time-domain channel response of pilot OFDM symbols; selecting time-domain channel value corresponding to the determined one or more than one most powerful paths; and substituting zero for the time-domain channel values that have not been selected; or determining a truncation range by analyzing time-domain channel response pilot OFDM symbols; selecting time-domain channel values within the truncation range; and substituting zero for the time-domain channel values that have not been selected.