A sliding-correlator-based SAGE algorithm for Mm-wave wideband channel parameter estimation

In this contribution, a high-resolution parameter estimation algorithm is derived based on the Space-Alternating Generalized Expectation-maximization (SAGE) principle for extracting multipath channel parameters from the output of sliding correlator (SC) which is used in millimeter-wave wideband channel measurements. By utilizing a parametric model describing the SC´s output, the multipath parameters can be estimated by exploiting both low- and high-frequency components in the SC´s output. Notice that conventional channel parameter estimation algorithms only make use of the time-dilated channel impulse response (CIR) calculated from the low-frequency component, and the high-frequency components, which are considered as distortions are discarded by low-pass filtering the SC´s output. The algorithm proposed here can also be applied to estimate the Doppler frequencies of multipath from the SC´s output containing only one observation of the time-dilated CIR, which is useful for the cases where channels change too fast to collect multiple observations of CIRs within channel coherence time. Simulations are conducted to verify the effectiveness of the proposed algorithm and evaluate its performance in terms of root mean square estimation errors.