Novel Optical Scattering-Based V2V Communications With Experimental Analysis

Taking advantage of the proliferation of optical wireless communications, this paper proposes a new paradigm of optical scattering (or ultraviolet) vehicle-to-vehicle (V2V) communication with experimental analysis based on extensive channel measurements at a wavelength of 266 nm. This new optical scattering-based V2V technology can ease a fundamental requirement of pointing, acquisition, and tracking (PAT) commonly found in conventional optical V2V systems and can also provide an additional robust capability of efficient non-line-of-sight (NLOS) V2V transmission. Based on the experiments, it is demonstrated that in a mobile V2V channel where the dynamics are changing rapidly, the scattering of the UV photons in the upper atmosphere produces some unique characteristics, resulting in greater randomness and severe fading. From the experimental results, we characterize the channel by a non-stationary time-frequency-selective fading channel with a statistical description of the time-frequency-varying power profile. An examination of the measured data reveals that the distribution of the fading statistics follows the Rayleigh distribution but a departure from the Rayleigh distribution is also observed. In addition, to facilitate the real-time capture of the dynamic behavior of the UV-based V2V channel, a Kalman filter-based algorithm is presented to estimate the time-varying optical scattering channel parameters. Finally, some open issues and challenges in the optical scattering-based V2V technology are presented.