  The sparsity of multipaths in the wideband channel has motivated the use of
compressed sensing for channel estimation. In this letter, we propose a
different approach to sparse channel estimation. We exploit the fact that $L$
taps of channel impulse response in time domain constitute a non-orthogonal
superposition of $L$ geometric sequences in frequency domain. This converts the
channel estimation problem into the extraction of the parameters of geometric
sequences. Numerical results show that the proposed scheme is superior to
existing algorithms in high signal-to-noise ratio (SNR) and large bandwidth
conditions.
