A method of estimating a symbol sequence contained in a received signal comprising a cyclic convolution of a transmitted Walsh code multiplexed data signal, hereinafter data signal, and a channel impulse response of a multipath channel, the data signal comprising modulation symbols and having a cyclic prefix appended before transmission, the method comprising: generating an estimate of the channel impulse response; calculating a transformation matrix; obtaining the inverse of the transformation matrix; and estimating the symbol sequence as a function of the transformation matrix and the received signal by multiplying the inverse of the transformation matrix and the received signal having the cyclic prefix removed, the symbol sequence comprising the modulation symbols, characterized in that: the transformation matrix relates the Walsh Hadamard Transform, WHT, domain spectra of the data signal, X, and the WHT domain spectra of the channel impulse response, H, to the received signal, wherein the relationship is given by: y = T H _ ⋅ X _, where y is the received signal, T is the transformation matrix, H is the Walsh Hadamard Transform, WHT, domain spectra of the channel impulse response, and X is the WHT domain spectra of the data signal, and where T H _ = 1 N ∑ i = 0 N 2 − 1 J i W Ξ ⊙ A i, with Ξ= H ·1 T, 1 T being an N -by-1 all-one vector, A (i) = 1/ N WM i W T, with W being the Walsh Hadamard transform matrix and M = 0 0 ⋯ 0 1 1 0 ⋯ 0 0 0 1 ⋯ 0 0 ⋮ ⋮ ⋱ ⋮ ⋮ 0 0 ⋯ 1 0 N × N, and J 0 = 0 0 0 ⋯ 0 0 0 0 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ⋮ O N 2 × N 2 0 0 0 ⋯ 0 0 0 0 ⋯ 1 0 0 0 ⋯ 0 0 0 0 ⋯ 0 O N 2 × N 2 ⋮ ⋮ ⋮ ⋱ ⋮ 0 0 0 ⋯ 0 0 0 0 ⋯ 1 N × N, J 1 = 0 0 0 ⋯ 0 0 0 0 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ⋮ O N 2 × N 2 0 0 0 ⋯ 1 0 0 0 ⋯ 0 0 0 0 ⋯ 0 0 0 0 ⋯ 0 O N 2 × N 2 ⋮ ⋮ ⋮ ⋱ ⋮ 0 0 0 ⋯ 1 0 0 0 ⋯ 0 N × N, J N 2 − 1 = 0 0 0 ⋯ 1 0 0 0 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ⋮ O N 2 × N 2 0 0 0 ⋯ 0 0 0 0 ⋯ 0 0 0 0 ⋯ 1 0 0 0 ⋯ 0 O N 2 × N 2 ⋮ ⋮ ⋮ ⋱ ⋮ 0 0 0 ⋯ 0 0 0 0 ⋯ 0 N × N, wherein the estimation of the symbol sequence is given by X _ = T H _ − 1 y. generating an estimate of the channel impulse response; calculating a transformation matrix; obtaining the inverse of the transformation matrix; and estimating the symbol sequence as a function of the transformation matrix and the received signal by multiplying the inverse of the transformation matrix and the received signal having the cyclic prefix removed, the symbol sequence comprising the modulation symbols, the transformation matrix relates the Walsh Hadamard Transform, WHT, domain spectra of the data signal, X, and the WHT domain spectra of the channel impulse response, H, to the received signal, wherein the relationship is given by: y = T H _ ⋅ X _, where y is the received signal, T is the transformation matrix, H is the Walsh Hadamard Transform, WHT, domain spectra of the channel impulse response, and X is the WHT domain spectra of the data signal, and where T H _ = 1 N ∑ i = 0 N 2 − 1 J i W Ξ ⊙ A i, with Ξ= H ·1 T, 1 T being an N -by-1 all-one vector, A (i) = 1/ N WM i W T, with W being the Walsh Hadamard transform matrix and M = 0 0 ⋯ 0 1 1 0 ⋯ 0 0 0 1 ⋯ 0 0 ⋮ ⋮ ⋱ ⋮ ⋮ 0 0 ⋯ 1 0 N × N, and J 0 = 0 0 0 ⋯ 0 0 0 0 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ⋮ O N 2 × N 2 0 0 0 ⋯ 0 0 0 0 ⋯ 1 0 0 0 ⋯ 0 0 0 0 ⋯ 0 O N 2 × N 2 ⋮ ⋮ ⋮ ⋱ ⋮ 0 0 0 ⋯ 0 0 0 0 ⋯ 1 N × N, J 1 = 0 0 0 ⋯ 0 0 0 0 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ⋮ O N 2 × N 2 0 0 0 ⋯ 1 0 0 0 ⋯ 0 0 0 0 ⋯ 0 0 0 0 ⋯ 0 O N 2 × N 2 ⋮ ⋮ ⋮ ⋱ ⋮ 0 0 0 ⋯ 1 0 0 0 ⋯ 0 N × N, J N 2 − 1 = 0 0 0 ⋯ 1 0 0 0 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ⋮ O N 2 × N 2 0 0 0 ⋯ 0 0 0 0 ⋯ 0 0 0 0 ⋯ 1 0 0 0 ⋯ 0 O N 2 × N 2 ⋮ ⋮ ⋮ ⋱ ⋮ 0 0 0 ⋯ 0 0 0 0 ⋯ 0 N × N, wherein the estimation of the symbol sequence is given by X _ = T H _ − 1 y.