A ray tracing algorithm using the discrete prolate spheroidal subspace

IEEE Trans. Veh. Technol.

Steinböck

et al. 2018

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Wave propagation in tunnels for vehicle-to-vehicle (V2V) communications scenarios is characterized by multiple diffuse reflections on tunnel surfaces as well as specular reflections on other objects inside the tunnel, leading to a non-stationary fading process. Such a fading process is difficult to model by ray tracing (RT), requiring a prohibitively high computational complexity due to the large number of diffuse reflections. In this work we propose two new ideas for modeling diffuse reflections in a non-stationary scenarios: (i) We partition the non-stationary fading process into multiple stationarity regions with a given extent in time and frequency for which approximate wide-sense stationarity can be assumed; (ii) we propose a hybrid model, tightly interlinking RT with a propagation graph, such that vertices for the propagation graph are obtained from interaction points calculated by RT for each stationarity region. We compare our hybrid model with measurement data in terms of the timevariant power-delay and the Doppler-power spectral-density as well as the root-mean square delay-and Doppler-spread. This analysis shows, that our hybrid model is the first numerical simulation model that is able to model diffuse reflections inside a tunnel with correct non-stationary (i.e. time-variant) temporal correlation for a non-stationary V2V communication link.

Section: Ray Tracing (Rt)mentioning

confidence: 99%

“…We reduce the complexity of RT by applying the SoCE algorithm [38] for each stationarity region. The SoCE algorithm relies on the assumption that within one stationarity region, the magnitude of each ray remains constant and only the phase changes.…”

Section: B Sum Of Complex Exponentials (Soce) Algorithmmentioning

confidence: 99%

A Hybrid Ray and Graph Model for Simulating Vehicle-to-Vehicle Channels in Tunnels

IEEE Trans. Veh. Technol.

Steinböck

et al. 2018

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“…The RT tool employed in the present work is for threedimensional (3D) environment and three major wave propagation mechanisms are taken into account: (i) line of sight (LOS), (ii) specular components as well as (iii) diffuse scattering [8]. The specular components contain reflection, penetration and diffraction contributions.…”

Section: Rt Channel Modelmentioning

confidence: 99%

Low-complexity sub-band divided ray tracing for UWB indoor channels

2014 IEEE Wireless Communications and Networking Conference (WCNC)

Meißner

Mani

et al. 2014

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Ray tracing has been extensively used to simulate indoor channel characteristics. For an ultra-wideband system, the channel characteristics vary significantly over the entire bandwidth. To cope with this, sub-band divided RT has been proposed by dividing the frequency of interest into multiple subbands and superposing the RT results at the individual center frequency of each subband. Thus, the computational complexity is directly proportional to the number of subbands. In this paper, we propose a mathematical method to significantly reduce the computational complexity of the sub-band divided RT, making it almost independent of the number of subbands. It is important to note that, based on our approach, not only the determination of the rays reaching a give location is made only once, but also the electromagnetic calculation of the received signal is not needed to perform repeatedly. The accuracy of low-complexity subband divided RT algorithm is verified through a measurement campaign.

“…All propagation paths connecting Tx and Rx are calculated based on the geometrical and electromagnetic description of the environment and the relevant propagation mechanisms. The geometrical relationships between the incident and the reflected/penetrated/diffracted rays are based on optical principles [8]. Complex dyadic coefficients for the reflection and penetration are obtained using Fresnel formulas, while the diffraction coefficient is calculated by the uniform theory of diffraction (UTD) [9].…”

Section: A Conventional Rtmentioning

confidence: 99%

A ray tracing algorithm for intelligent transport systems in tunnels

2014 IEEE 6th International Symposium on Wireless Vehicular Communications (WiVeC 2014)

Shivaldova³

et al. 2014

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It is well-known that the radio wave propagation mechanisms inside a tunnel are different from the typical outdoor and indoor situations. Since the tunnels represent a significant type of vehicular environments, understanding the channel characteristics for the in-tunnel scenario is crucial for intelligent transport systems design. A widely used tool for simulating channel characteristics for outdoor and indoor scenarios is a deterministic propagation prediction tool, known as ray tracing (RT). However, RT applied for tunnel scenarios has not been studied adequately.In this paper, we first evaluate the real-world in-tunnel vehicleto-vehicle radio channel measurements on the basis of timevarying power delay profile analysis. Secondly we introduce a RT tool that includes influence of the moving objects, to predict wave propagation mechanisms in the tunnel. In order to reduce computational complexity of RT, we suggest to combine an approximate algorithm for the higher-order reflection components with conventional RT and use a novel subdivision algorithm for modeling the diffuse scattering. Combining the higher-order reflection algorithm with conventional RT allows us to obtain more accurate delay spread results. The numerical simulations show that contribution of both the higher-order reflection and the diffuse components are equally important for the in-tunnel scenarios.Keywords-ray tracing (RT), intelligent transport systems, vehicle-to-vehicle, tunnel, computational complexity.