A method for time delay measurement based on eigen-subspace is proposed.In our method

the time delay measurement is first transformed into the frequency domain

in which the problem is converted into the parameter estimation of sinusoidal signals with low-pass envelopes by computing the inverse discrete fourier transform (IDFT) of the cross-correlation function for sent signal and received signal.Next

a lower order covariance matrix of signal matrix is constructed by rebuilding the IDFT series.Then

a multiple-signal-classification (MUSIC) type algorithm is applied to achieve the time delay of each multipath signals.The computational complexity of the method is reduced significantly compare to classical MUSIC approach.Both theory analysis and simulation verify the method.Simulation shows computational complexity of the method is reduced significantly in the cost of decreasing the performance of Time Delay Measurement.