A measurement-based channel model for vehicular communications in tunnels

In this paper, we present a new version of the iterative nonlinear least square approximation (INLSA) algorithm for the design of measurement-based channel simulators. The proposed method aims to match the time-variant impulse response (TVIR) of the simulation model to that of the measured channel. The propagation delays are discerned directly from the measurements, whereas the gains, the Doppler frequencies, and the phases are computed iteratively by minimizing a matching error norm. We evaluate the performance of the proposed method in terms of the approximation of the transfer function and correlation properties of the measured channel. We demonstrate how the resulting channel simulator can be deployed for a more reliable estimation of the channel statistics. The obtained results indicate that the proposed method allows a precise emulation of the measured channel impulse response. Its remarkable performance and simplicity makes the proposed method a powerful tool for designing realistic channel models.