A method for achieving frequency domain scheduling in a time division duplex system, characterized in that the method comprises the steps of: a first device transmits a non pre-coded reference symbol to a second device; the second device obtains a channel impulse response matrix from the reference symbol transmitted from the first device, and from the channel impulse response matrix, obtains linear spatial domain pre-coding matrix used in the candidate physical resource blocks to transmit data to the first device; from the channel impulse response matrix and the linear spatial domain pre-coding matrix, the second device obtains the channel quality indicator of each of the candidate physical resource blocks; and the frequency domain scheduling is performed by a base station according to said channel quality indicator, wherein the obtaining of the channel quality indicator of each of the candidate physical resource blocks comprises the steps of: for every physical resource block, obtaining the equivalent channel matrix of each sub-carrier according to the linear spatial domain pre-coding matrix and the channel impulse response matrix corresponding to each sub-carrier in the physical resource block, wherein the equivalent channel matrix is the product of the conjugate transpose of the channel impulse response matrix and the linear spatial domain pre-coding matrix; determining the receiving signal-to-noise ratio on each sub-carrier of the physical resource block as a function of the equivalent channel matrix; and obtaining the equivalent signal-to-noise ratio on the corresponding physical resource block according to the receiving signal-to-noise ratio of each sub-carrier, wherein the equivalent signal-to-noise ratio is a function of a signal-to-noise ratio on all of the sub-carriers within the physical resource block and the signal-to-noise ratio on all the sub-carriers within the physical resource block is the collection for the number of sub-carriers within the physical resource block of the receiving signal-to-noise ratio on each of the sub-carriers within the physical resource block; and determining the channel quality indicator on the physical resource block according to the equivalent signal-to-noise ratio. a first device transmits a non pre-coded reference symbol to a second device; the second device obtains a channel impulse response matrix from the reference symbol transmitted from the first device, and from the channel impulse response matrix, obtains linear spatial domain pre-coding matrix used in the candidate physical resource blocks to transmit data to the first device; from the channel impulse response matrix and the linear spatial domain pre-coding matrix, the second device obtains the channel quality indicator of each of the candidate physical resource blocks; and the frequency domain scheduling is performed by a base station according to said channel quality indicator, wherein the obtaining of the channel quality indicator of each of the candidate physical resource blocks comprises the steps of: for every physical resource block, obtaining the equivalent channel matrix of each sub-carrier according to the linear spatial domain pre-coding matrix and the channel impulse response matrix corresponding to each sub-carrier in the physical resource block, wherein the equivalent channel matrix is the product of the conjugate transpose of the channel impulse response matrix and the linear spatial domain pre-coding matrix; for every physical resource block, obtaining the equivalent channel matrix of each sub-carrier according to the linear spatial domain pre-coding matrix and the channel impulse response matrix corresponding to each sub-carrier in the physical resource block, wherein the equivalent channel matrix is the product of the conjugate transpose of the channel impulse response matrix and the linear spatial domain pre-coding matrix; determining the receiving signal-to-noise ratio on each sub-carrier of the physical resource block as a function of the equivalent channel matrix; and obtaining the equivalent signal-to-noise ratio on the corresponding physical resource block according to the receiving signal-to-noise ratio of each sub-carrier, wherein the equivalent signal-to-noise ratio is a function of a signal-to-noise ratio on all of the sub-carriers within the physical resource block and the signal-to-noise ratio on all the sub-carriers within the physical resource block is the collection for the number of sub-carriers within the physical resource block of the receiving signal-to-noise ratio on each of the sub-carriers within the physical resource block; and determining the channel quality indicator on the physical resource block according to the equivalent signal-to-noise ratio.