Sparsity in the Delay-Doppler Domain for Measured 60 GHz Vehicle-to-Infrastructure Communication Channels

We report results from millimeter wave vehicle-to-infrastructure (V21) channel measurements conducted on Sept. 25, 2018 in an urban street environment, down-town Vienna, Austria. Measurements of a frequency-division multiplexed multiple-input single-output channel have been acquired with a time-domain channel sounder at 60 GHz with a bandwidth of 100 MHz and a frequency resolution of 5 MHz. Two horn antennas were used on a moving transmitter vehicle: one horn emitted a beam towards the horizon and the second horn emitted an elevated beam at 15-degrees up-tilt. This configuration was chosen to assess the impact of beam elevation on V2I communication channel characteristics: propagation loss and sparsity of the local scattering function in the delay-Doppler domain. The measurement results within urban speed limits show high sparsity in the delay-Doppler domain.