  A framework is proposed for developing and evaluating algorithms for
extracting multipath propagation components (MPCs) from measurements collected
by sounders at millimeter-wave (mmW) frequencies. To focus on algorithmic
performance, an idealized model is proposed for the spatial frequency response
of the propagation environment measured by a sounder. The input to the sounder
model is a pre-determined set of MPC parameters that serve as the "ground
truth." A three-dimensional angle-delay (beamspace) representation of the
measured spatial frequency response serves as a natural domain for implementing
and analyzing MPC extraction algorithms. Metrics for quantifying the error in
estimated MPC parameters are introduced. Initial results are presented for a
greedy matching pursuit algorithm that performs a least-squares (LS)
reconstruction of the MPC path gains within the iterations. The results
indicate that the simple greedy-LS algorithm has the ability to extract MPCs
over a large dynamic range, and suggest several avenues for further performance
improvement through extensions of the greedy-LS algorithm as well as by
incorporating features of other algorithms, such as SAGE and RIMAX.
