Position-Specific Statistics of 60 GHz Vehicular Channels During Overtaking

Abstract

The time-variant vehicle-to-vehicle radio propagation channel in the frequency band from 59.75 to 60.25 GHz has been measured in an urban street in the city center of Vienna, Austria. We have measured a set of 30 vehicle-to-vehicle channel realizations to capture the effect of an overtaking vehicle. Our experiment was designed for characterizing the large-scale fading and the small-scale fading depending on the overtaking vehicle's position. We demonstrate that large overtaking vehicles boost the mean receive power by up to 10 dB. The analysis of the small-scale fading reveals that the two-wave with diffuse power (TWDP) fading model is adequate. By means of the model selection, we demonstrate the regions where the TWDP model is more favorable than the customarily used the Rician fading model. Furthermore, we analyze the time selectivity of our vehicular channel. To precisely define the Doppler and delay resolutions, a multitaper spectral estimator with discrete prolate spheroidal windows is used. The delay and Doppler profiles are inferred from the estimated local scattering function. Spatial filtering by the transmitting horn antenna decreases the delay and Doppler spread values. We observe that the RMS Doppler spread is below one-tenth of the maximum Doppler shift 2f v/c. For example, at 60 GHz, a relative speed of 30 km/h yields a maximum Doppler shift of approximately 3300 Hz. The maximum RMS Doppler spread of all observed vehicles is 450 Hz; the largest observed RMS delay spread is 4 ns.INDEX TERMS 5G mobile communication, automotive engineering, communication channels, fading channels, intelligent vehicles, millimeter wave propagation, millimeter wave measurement, multipath channels, RMS delay spread, RMS Doppler spread, parameter extraction, time-varying channels, two-wave with diffuse power fading, wireless communication.

Improved RMS Delay Spread Estimation for mmWave Channels Using Savitzky–Golay Filters

“…If we also consider the center frequency of the channel model f 0 = 60 GHz and 10 GHz channel bandwidth, we can assume that the channel model is frequency selective and represents the small-scale fading case. This assumption is valid for mmWave bands [13,14]. Such a channel can be described by CIR as:…”

“…It also serves to obtain an approximate estimate of the range of suitable S-G filter cut-off frequencies f c for application to noisy |H(jω)| and illustrate whether it adds some improvement to the basic τ RMS estimation method described by Witrisal [2]. If we relate the used two-ray channel model to the current widely utilized and discussed two-wave channel model with diffuse power fading (TWDP), which assumess an interference of two strong signals (specular components) and a number of diffuse signals, then the ratio of specular-to-diffuse power K TWDP → ∞ (only specular components are considered) and the ratio of the specular components ∆ TWDP equals 1 [13]. The examination of a number of combinations of the channel model parameters and the channel model types goes beyond the scope of this work.…”

Channel Characterization for Vehicle-to-Infrastructure Communications in Millimeter-Wave Band

“…In this section, by comparing the results obtained from the measurement campaign in [38] and the simulation results obtained through the RT simulator under the same environments, the accuracy of the RT simulator is verified.…”

Modeling and Analysis of MmWave V2X Networks With Vehicular Platoon Systems

“…Nowadays, thanks to the advance of integrated circuits used in mmWave bands [11][12][13], low-cost devices become possible and hence the study on mmWave V2X networks is reinvigorated. Recently, several research efforts have been devoted to exploring such networks [14][15][16][17]. During overtaking, the actual V2V propagation channel for the frequency range from 59.75 to 60.25 GHz was measured in [14].…”

“…Recently, several research efforts have been devoted to exploring such networks [14][15][16][17]. During overtaking, the actual V2V propagation channel for the frequency range from 59.75 to 60.25 GHz was measured in [14]. Since vehicular radars are also operated in mmWave bands, the authors in [15] proposed an adaptive cruise control mode to enhance mmWave V2X communications by incorporating radar sensing capabilities.…”