A method for transmitting data, comprising: determining one or more orthogonal frequency division multiplexing, OFDM, symbols for transmitting data in an uplink basic unit, wherein a starting transmission time of the uplink basic unit is preset advance time ahead of a starting transmission time of a downlink basic unit, and the preset advance time is determined according to a dynamic timing advance and a timing advance offset; and transmitting data on the determined one or more OFDM symbols; characterised in that the uplink basic unit comprises n1 OFDM symbols, each of first S OFDM symbols of the n1 OFDM symbols has a cyclic prefix with a first time length, a (S+1)th OFDM symbol has a cyclic prefix with a second time length, and each of at least one OFDM symbol of remaining n1-S-1 OFDM symbols other than first S+1 OFDM symbols has a cyclic prefix with the second time length, wherein the n1 OFDM symbols have a same valid data length, the first time length is less than the second time length, S<n1, and S and n1 are positive integers; or the uplink basic unit comprises n1 OFDM symbols, an additional cyclic prefix or an interval exists between a Sth OFDM symbol and a (S+1)th OFDM symbol of the n1 OFDM symbols, an additional cyclic prefix or an interval exists among remaining n1-S-1 OFDM symbols other than first S+1 OFDM symbols, wherein the additional cyclic prefix or the interval between the Sth OFDM symbol and the (S+1)th OFDM symbol is the same as the additional cyclic or the interval among the remaining n1-S-1 OFDM symbols, the n1 OFDM symbols have a same cyclic prefix length and a same valid data length, the same cyclic prefix length is a first time length, no information is transmitted or received in the interval, S<n1, and S and n1 are positive integers; wherein a time length of the S OFDM symbols is a first timing advance time offset of the uplink basic unit relative to an uplink reference unit or a part of the first timing advance time offset of the uplink basic unit relative to the uplink reference unit, wherein a starting transmission time of the uplink reference unit has a second timing advance offset relative to a starting transmission time of a downlink reference unit, the starting transmission time of the downlink reference unit is the same as the starting transmission time of the downlink basic unit, the uplink reference unit and the uplink basic unit have a same time length, the downlink reference unit and the downlink basic unit have a same time length, wherein the first timing advance time offset and the second timing advance time offset are both greater than 0. determining one or more orthogonal frequency division multiplexing, OFDM, symbols for transmitting data in an uplink basic unit, wherein a starting transmission time of the uplink basic unit is preset advance time ahead of a starting transmission time of a downlink basic unit, and the preset advance time is determined according to a dynamic timing advance and a timing advance offset; and transmitting data on the determined one or more OFDM symbols; characterised in that the uplink basic unit comprises n1 OFDM symbols, each of first S OFDM symbols of the n1 OFDM symbols has a cyclic prefix with a first time length, a (S+1)th OFDM symbol has a cyclic prefix with a second time length, and each of at least one OFDM symbol of remaining n1-S-1 OFDM symbols other than first S+1 OFDM symbols has a cyclic prefix with the second time length, wherein the n1 OFDM symbols have a same valid data length, the first time length is less than the second time length, S<n1, and S and n1 are positive integers; or the uplink basic unit comprises n1 OFDM symbols, an additional cyclic prefix or an interval exists between a Sth OFDM symbol and a (S+1)th OFDM symbol of the n1 OFDM symbols, an additional cyclic prefix or an interval exists among remaining n1-S-1 OFDM symbols other than first S+1 OFDM symbols, wherein the additional cyclic prefix or the interval between the Sth OFDM symbol and the (S+1)th OFDM symbol is the same as the additional cyclic or the interval among the remaining n1-S-1 OFDM symbols, the n1 OFDM symbols have a same cyclic prefix length and a same valid data length, the same cyclic prefix length is a first time length, no information is transmitted or received in the interval, S<n1, and S and n1 are positive integers; wherein a time length of the S OFDM symbols is a first timing advance time offset of the uplink basic unit relative to an uplink reference unit or a part of the first timing advance time offset of the uplink basic unit relative to the uplink reference unit, wherein a starting transmission time of the uplink reference unit has a second timing advance offset relative to a starting transmission time of a downlink reference unit, the starting transmission time of the downlink reference unit is the same as the starting transmission time of the downlink basic unit, the uplink reference unit and the uplink basic unit have a same time length, the downlink reference unit and the downlink basic unit have a same time length, wherein the first timing advance time offset and the second timing advance time offset are both greater than 0.