METHOD FOR ORIENTING REFLECTORS OF A TERAHERTZ COMMUNICATIONS SYSTEM

• US 20190326669A1
• Filed: 04/23/2019
• Published: 10/24/2019
• Est. Priority Date: 04/24/2018
• Status: Active Grant

• Current Assignee: Fundacion Centro De Tecnologias De Interaccion Visual Y Comunicaciones Vicomtech
• Original Assignee: Fundacion Centro De Tecnologias De Interaccion Visual Y Comunicaciones Vicomtech
• Inventors: GAINES, Sean, OTAEGUI MADURGA, Oihana, VELEZ ISASMENDI, Gorka, ARREGUI MARTIARENA, Harbil, MUJIKA AMUNARRIZ, Andoni, LOYO MENDIVIL, Estibaliz
• Granted Patent: US 11,011,839 B2
• Time in Patent Office: Days
• CPC Class Codes: G06N 20/20 Ensemble learning
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: G08G 1/0141 for traffic information dissemination
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors
• CPC Class Codes: H01Q 19/18 having two or more spaced reflecting surfaces H01Q19/20 takes precedence
• CPC Class Codes: H01Q 3/20 wherein the primary active element is fixed and the reflecting device is movable
• CPC Class Codes: H01Q 5/30 Arrangements for providing operation on different wavebands

Abstract

A method for orienting reflectors of a communications system in a zone, wherein the communications system includes an antenna and the reflectors. The antenna is operable in one or more frequencies in a frequency range from 0.1 THz to 10.0 THz, with each of the reflectors being spaced apart from each other and the antenna. The method includes the steps of digitally predicting a future motor vehicle density distribution in the zone based on obtained past motor vehicle density distributions in the zone; digitally computing an orientation of each reflector such that the estimated power reception of electromagnetic waves radiated by the antenna is globally maximized for each motor vehicle of the future motor vehicle density distribution; and orienting each reflector according to the digitally computed orientation.

Claims

1. A method for orienting a plurality of reflectors of a communications system in a zone, the communications system comprising an antenna and the plurality of reflectors, the antenna being operable in one or more frequencies in a frequency range from 0.1 THz to 10.0 THz, each reflector of the plurality of reflectors being spaced apart from each other and the antenna, the method including the steps of:

digitally predicting a future motor vehicle density distribution in the zone based on a plurality of obtained past motor vehicle density distributions in the zone;

digitally computing an orientation of each reflector of the plurality of reflectors such that estimated power reception of electromagnetic waves radiated by the antenna is globally maximized for each motor vehicle of the future motor vehicle density distribution; and

orienting each reflector of the plurality of reflectors according to the digitally computed orientation.

2. The method of claim 1, wherein digitally predicting the future motor vehicle density distribution in the zone based on the plurality of obtained past motor vehicle density distributions in the zone includes the steps of:

obtaining a number of motor vehicles in the zone in a plurality of time spans;

digitally providing a grid for each time span of the plurality of time spans, each grid comprising a plurality of cells each representing a number of motor vehicles in a corresponding portion of the zone in a corresponding time span of the plurality of time spans; and

digitally providing a prediction grid for a future time span based at least on the grids of the plurality of time spans, the prediction grid comprising a plurality of cells each representing a number of predicted motor vehicles in a corresponding portion of the zone in the future time span.

3. The method of claim 2, wherein digitally computing the orientation of each reflector of the plurality of reflectors such that estimated power reception of electromagnetic waves radiated by the antenna is globally maximized for each motor vehicle of the future motor vehicle density distribution includes the steps of:

digitally estimating a power reception of electromagnetic waves radiated by the antenna at each cell of the prediction grid and with a predetermined orientation of each reflector of the plurality of reflectors; and

digitally computing an orientation of each reflector of the plurality of reflectors based on the estimation of the power reception such that an estimated power reception is globally maximized for each predicted motor vehicle of the prediction grid.

4. The method of claim 3, wherein:

each time span of the plurality of time spans has a first time duration, the first time duration preferably being equal to or greater than 30 seconds and less than or equal to 60 seconds; and

the future time span starts after a second time duration upon ending of a last time span of the plurality of time spans, the second time duration being equal to or greater than two times the first time duration, and equal to or less than five times the first time duration.

5. The method of claim 3, wherein:

obtaining the number of motor vehicles in the zone in the plurality of time spans comprises the step of obtaining the number of motor vehicles in the zone at least in as many pluralities of time instants as time spans of the plurality of time spans, wherein each time span of the plurality of time spans comprises a corresponding plurality of time instants of the pluralities of time instants; and

each cell of the grid for each time span represents the number of motor vehicles in the portion of the zone corresponding to the cell as an aggregate of each time instant of the plurality of time instants of the corresponding time span.

6. The method of claim 5, wherein:

the plurality of time spans at least comprises a first time span, a second time span, and a third time spans;

the pluralities of time instants at least comprise a first time instant, a second time instant, and a third time instants; and

the first time span, the second time span, and the third time spans respectively comprise the first time instant, the second time instant, and the third time instants.

7. The method of claim 2, wherein digitally providing a prediction grid for a future time span includes the steps of:

digitally computing neighbors with a neighbor order parameter Π

for each cell of the grids for the plurality of time spans, the neighbor order parameter Π

being 1 or 2;

digitally discarding each cell of the grids for the plurality of time spans for which the number of motor vehicles is lower than a predefined threshold; and

digitally running a regression algorithm on the grids for the plurality of time spans resulting from the steps of digitally computing the neighbors and digitally discarding cells, thereby providing the prediction grid, the regression algorithm preferably being a random forest regression algorithm.

8. The method of claim 2, wherein digitally computing an orientation of each reflector of the plurality of reflectors includes the step of:

digitally running a genetic algorithm with the prediction grid and the digitally estimated power reception, the genetic algorithm digitally computing the orientation of each reflector of the plurality of reflectors.

9. The method of claim 8, wherein the genetic algorithm comprises:

a plurality of individuals, each individual encoding a configuration of the plurality of reflectors, each individual comprising a plurality of genes, each gene encoding an orientation angle of a reflector of the plurality of reflectors;

recombination of two individuals whereby a first half of the orientation angles are taken from a first individual of the two individuals and a second half of the orientation angles are taken from a second individual of the two individuals; and

mutation whereby values of a fourth of the orientation angles are increased or decreased.

10. The method of claim 9, wherein the genetic algorithm further comprises initialization with a first population whereby each gene of each individual of the plurality of individuals has a value:

randomly assigned;

or

assigned according to a digitally computed orientation angle of a corresponding reflector, the digitally computed orientation angle being a previous digital computation of an orientation of each reflector of the plurality of reflectors based on a previous estimation of the power reception such that an estimated power reception is globally maximized for each predicted motor vehicle of a different prediction grid.

11. The method of claim 2, wherein obtaining the number of motor vehicles in the zone in the plurality of time spans includes the step of:

receiving position information of the motor vehicles in the plurality of time spans, the position information being provided by the communications system or a global navigation satellite system;

or

detecting the presence of motor vehicles in the zone in the plurality of time spans with one or more presence sensors, the one or more presence sensors at least comprising one of;

one or more cameras, one or more lidars, and one or more radars.

12. The method of claim 2, wherein:

both the number of motor vehicles of each grid for each time span and the number of predicted motor vehicles of the prediction grid are an aggregate or an average of the number of motor vehicles present and predicted in the corresponding portion of the zone, respectively, in the corresponding time span and the future time span; and

the motor vehicles counted in both the number of motor vehicles of each grid for each time span and the number of predicted motor vehicles of the prediction grid are motor vehicles connected to the communications system.

13. The method of claim 1, wherein orienting each reflector of the plurality of reflectors includes operating an actuator of each reflector of the plurality of reflectors thereby orienting each reflector.

14. The method of claim 1, wherein:

the zone comprises a roundabout or a junction; and

each portion of the zone corresponding to a cell of the grids for the plurality of time spans and the prediction grid has an area equal to or less than 50 m², and preferably equal to 25 m².

15. A communications system comprising:

an antenna operable in one or more frequencies in a frequency range from 0.1 THz to 10.0 THz, the antenna being located in a zone;

a plurality of reflectors, each reflector of the plurality of reflectors being located in the zone and being spaced apart from each other and the antenna; and

at least one processor configured to perform the following steps of the method of claim 3;

digitally providing a grid for each time span of the plurality of time spans, each grid comprising a plurality of cells each representing a number of motor vehicles in a corresponding portion of the zone in a corresponding time span of the plurality of time spans;

digitally providing a prediction grid for a future time span based at least on the grids of the plurality of time spans, the prediction grid comprising a plurality of cells each representing a number of predicted motor vehicles in a corresponding portion of the zone in the future time span;

digitally estimating a power reception of electromagnetic waves radiated by the antenna at each cell of the prediction grid and with a predetermined orientation of each reflector of the plurality of reflectors; and

digitally computing an orientation of each reflector of the plurality of reflectors based on the estimation of the power reception such that an estimated power reception is globally maximized for each motor vehicle according to the prediction grid;

each reflector of the plurality of reflectors being configured to be oriented according to the orientation digitally computed by the at least one processor.