Impact of Vehicular Array Position on Urban MIMO Channel Characteristics

Abstract

MIMO channel measurements have been performed in urban environments with antenna arrays positioned on the roof and sides of the measurement vehicle. Analysis of the data shows that the array's position on the vehicle, along with the location and orientation of the vehicle with respect to the transmitter, can have a considerable impact on the channel characteristics observed. Array elements on the vehicle's roof receive the same multipath components, and, therefore, have identically distributed channel responses. However, the characteristics of the multipath components observed at each side of the vehicle can differ significantly. Specifically, shadowing from the vehicle combined with the directionality of the side-mounted array elements affects the angular distribution and powers of the received multipath components, affecting the achievable diversity and channel capacity. This can have significant impact on system performance and should be considered when designing and analyzing vehicular-based signalling techniques.

Challenges Toward Wireless Communications for High-Speed Railway

“…It contains four types of parameters for MIMO antenna array configuration corresponding to the four different channel regions defined in [61] when the train runs toward the BS. For the optimal MIMO antenna and location, Christopher et al [64] have carried out a vehicular (automobile) MIMO measurement to investigate the effect of antenna array location, roof, or two sides of the car on the MIMO system performance. The array on the roof can obtain more signal power.…”

Measurement‐based analysis of cross‐layer adaptation for MIMO in mobile urban environments

“…The average BERs on the two segments are also much closer for M/L = 3/2 at 370 MHz than at 2 GHz. This appears to be because of the different reflected multipath components in the intersection: at 2 GHz, it was seen in [2] that there are multipath components arriving from the east side, away from the transmitter, increasing the total received power as the vehicle enters and exits the intersection. This effect is seen at the previous intersection with Gloucester St. (Fig.…”

“…x (t) = E X (t) 2 F / N t N r for M/L = 3/2 at a delay of t = 5 ms, where E X was defined in Section 3.3 as…”

“…The performance of MIMO systems is highly dependent on the local environment in the area between and surrounding the transmitter and receiver, which determines the channel characteristics, in particular the number, strength and angles of multipath components. For mobile communications, the channel characteristics change with distance [1,2] and the radio system must take into account the effects of these changes to maintain quality of service.…”

Limits on Estimating Autocorrelation Matrices from Mobile MIMO Measurements

“…In practice, within an urban canyon, the strongest multipath components arrive from angles close to the front and/or rear of the vehicle, and not from the sides [6]. In the intersection, as seen in [10], the signal power arrives predominantly from the side, along the direction of the intersecting street, with some reflections off the buildings on opposite corners. These directional components lead to higher temporal correlations and greater variation from subblock to subblock as the angles of arrival change with distance.…”