Coherence Time and Doppler Spectrum of V2V Channel with Moving Scatterer Based on Autocorrelation Function

—Vehicular Ad Hoc Network (VANET) technology allows vehicles to communicate with each other in mobile conditions. Modeling the channel by observing the movement of the vehicle as the transmitter, the receiver and the surrounding moving objects has been done and generates a large Doppler Shift. This modeling affects the Coherence Time value that determines the duration of the channel to not change at a certain time period. In this paper, the Coherence Time value was obtained through the autocorrelation of complex envelope V2V channel modeling. Furthermore, for various speeds of the transmitter, receiver, and scatterer, the Coherence Time values were validated using the equation on the correlation limit value that had been determined by the auto-correlation results. In addition, the obtained Doppler Spectrum values were validated through the inverse Fourier Transform process of the V2V channel complex autocorrelation function. Coherence Time value at the limit of autocorrelation function> 0.5 that was used on the wireless communication system channel had a slight difference with the results of V2V channel validation that generated a limit of autocorrelation function <0.5 at the same Coherence Time value. Meanwhile, the value of Coherence Time from the Geometric Mean results had a limit of the autocorrelation function at the position around of the first minimum value that approached zero.