Ray tracing technique for wireless channel measurements
The computer-implemented method includes simulating, by a processor, using an electromagnetic solver including ray launching or ray tracing, multiple rays that reach a vicinity of a receiver of a wireless channel, determining locations of interactions of the rays with an environment of the wireless channel, post-processing, using one or more of the multiple rays, information about received signal at the receiver to obtain temporal variations therein, and determining a characteristic of the wireless channel using results of the post-processing.
1. A computer implemented method, comprising:
simulating, by a processor, using an electromagnetic solver including ray launching or ray tracing, multiple rays that reach a vicinity of a receiver of a wireless channel;
determining locations of interactions of the rays with an environment of the wireless channel;
post-processing, using one or more of the multiple rays, information about received signal at the receiver to obtain temporal variations therein; and
determining a characteristic of the wireless channel using results of the post-processing;
further including estimating the one or more rays by:
generating a ray tracing model and incorporating effects from one or more of moving cars, moving vegetation or moving people, wherein the generating the ray tracing model includes controlling a beam width of a given ray to be below a threshold, wherein the given ray is split into subcones in case that a cone cross section of the given ray exceeds the threshold.
2. The method of claim 1 , wherein the post-processing comprises determining a Doppler spectrum and/or temporal Rice factor of the one or more rays.
3. The method of claim 2 , wherein in case that the beam width is larger than size of a vehicle, and the temporal Rice factor of the given ray is determined through weighting that depends on a ratio of an area covered by the cone corresponding to the given ray over the size of the vehicle.
4. The method of claim 1 , wherein the estimating the one or more rays includes identifying rays affected by moving vehicles and obtaining Doppler spectra and Rice factors therefor using a stochastic traffic model.
5. The method of claim 4 , wherein the stochastic traffic model includes a probabilistic model of locations of the moving vehicles or a model descripting inter-vehicle distance and a number of vehicles passing through an area covered by the wireless channel per unit time.
6. The method of claim 1 , wherein the ray tracing model includes one or more of scatterers including one or more of moving discrete objects or moving clusters of objects.
7. A computer implemented method, comprising:
simulating, by a processor, using an electromagnetic solver including ray launching or ray tracing, multiple rays that reach a vicinity of a receiver of a wireless channel;
determining locations of interactions of the rays with an environment of the wireless channel;
post-processing, using one or more of the multiple rays, information about received signal at the receiver to obtain temporal variations therein; and
determining a characteristic of the wireless channel using results of the post-processing;
wherein the ray tracing further includes:
dividing the multiple rays into at least two groups, wherein the at least two groups comprise:
a first group of rays that hit ground and a second group of rays that do not hit the ground; or
a group of rays that is used to determine a time-invariant portion of the wireless channel and another group of rays that is used to determine a time-variant portion using rays that hit foliage or a person that is indoors near the receiver.
8. The method of claim 7 , wherein the ray tracing further includes:
identifying, from the first group of rays that hit the ground, a set of rays that hit a vehicle; and
ascertaining, for a given ray in the set of rays, whether the given ray is shadowed off by another vehicle based on dimensions of the another vehicles.
9. The method of claim 8 , wherein the shadowing off is calculated by choosing the given ray stochastically and based on statistics related to a traffic model of other vehicles around the vehicle.
10. The method of claim 7 , wherein the post-processing comprises determining a Doppler spectrum and/or temporal Rice factor of the one or more rays.
11. The method of claim 10 , wherein in case that a beam width is larger than size of a vehicle, and a temporal Rice factor of a given ray is determined through weighting that depends on a ratio of an area covered by a cone corresponding to the given ray over the size of the vehicle.
12. An apparatus comprising a processor configure to implement a method, comprising:
simulating, by the processor, using an electromagnetic solver including ray launching or ray tracing, multiple rays that reach a vicinity of a receiver of a wireless channel;
determining locations of interactions of the rays with an environment of the wireless channel;
post-processing, using one or more of the multiple rays, information about received signal at the receiver to obtain temporal variations therein; and
determining a characteristic of the wireless channel using results of the post-processing;
wherein the method further includes estimating the one or more rays by:
generating a ray tracing model and incorporating effects from one or more of moving cars, moving vegetation or moving people, wherein the generating the ray tracing model includes controlling a beam width of a given ray to be below a threshold, wherein the given ray is split into subcones in case that a cone cross section of the given ray exceeds the threshold.
13. The apparatus of claim 12 , wherein the post-processing comprises determining a Doppler spectrum and/or temporal Rice factor of the one or more rays.
14. The apparatus of claim 12 , wherein in case that the beam width is larger than size of a vehicle, and a temporal Rice factor of the given ray is determined through weighting that depends on a ratio of an area covered by the cone corresponding to the given ray over the size of the vehicle.
15. The apparatus of claim 12 , wherein the estimating the one or more rays includes identifying rays affected by moving vehicles and obtaining Doppler spectra and Rice factors therefor using a stochastic traffic model.
16. The apparatus of claim 15 , wherein the stochastic traffic model includes a probabilistic model of locations of the moving vehicles or a model descripting inter-vehicle distance and a number of vehicles passing through an area covered by the wireless channel per unit time.
17. The apparatus of claim 12 , wherein the ray tracing model includes one or more of scatterers including one or more of moving discrete objects or moving clusters of objects.
18. An apparatus comprising a processor configure to implement a method, comprising:
simulating, by the processor, using an electromagnetic solver including ray launching or ray tracing, multiple rays that reach a vicinity of a receiver of a wireless channel;
determining locations of interactions of the rays with an environment of the wireless channel;
post-processing, using one or more of the multiple rays, information about received signal at the receiver to obtain temporal variations therein; and
determining a characteristic of the wireless channel using results of the post-processing;
wherein the ray tracing further includes:
identifying, from a first group of rays that hit the ground, a set of rays that hit a vehicle; and
ascertaining, for a given ray in the set of rays, whether the given ray is shadowed off by another vehicle based on dimensions of the another vehicles.
19. The apparatus of claim 18 , wherein the shadowing off is calculated by choosing the given ray stochastically and based on statistics related to a traffic model of other vehicles around the vehicle.
20. The apparatus of claim 18 , wherein the post-processing comprises determining a Doppler spectrum and/or temporal Rice factor of the one or more rays.