In-Vehicle Channel Measurement, Characterization, and Spatial Consistency Comparison of $\text{30}\hbox{--}\text{11 GHz}$ and $\text{55}\hbox{--}\text{65 GHz}$ Frequency Bands

Abstract

The paper provides real-word wireless measurement data of the intravehicular channel for both the $\text{3}\hbox{--}\text{11 GHz}$ and the $\text{55}\hbox{--}\text{65 GHz}$ frequency bands under similar conditions. By spatially averaging channel impulse response realizations within a $10\times 10$ grid, we obtain the power-delay profile (PDP). The data measured at $\text{3}\hbox{--}\text{11 GHz}$ and $\text{55}\hbox{--}\text{65 GHz}$ exhibit significant differences in terms of root mean square (RMS) delay spread, number of resolvable clusters, and variance of the maximal excess delay. Moreover, we evaluate the spatial stationarity via the Pearson correlation coefficient and via the PDP collinearity, depending on the distance in the grid. The measured and calculated results indicate that a strong reverberation inside the vehicle produces similar PDPs within the range of approximately ten wavelengths. We also provide a linear piecewise model of the PDP in logarithmic scale and a generalized extreme value model of a small-scale signal fading. Our channel model is validated utilizing the Kolmogorov–Smirnov test.