1. A method for deriving an estimate of a wireless channel in a wireless communication system, comprising: obtaining an intermediate vector derived based on K sub-vectors of a vector for a first channel estimate and at least two discrete Fourier transform (DFT) sub-matrices for a DFT matrix, wherein the DFT matrix corresponds to the vector for the first channel estimate and K is an integer greater than one; obtaining an intermediate matrix for the DFT matrix; and deriving a second channel estimate based on the intermediate vector and the intermediate matrix.