DE102020200023B4 - Method and device for the highly accurate determination of the position and/or orientation of an object to be located and fixed station for a mobile radio communication system - Google Patents

Abstract

Method for the highly accurate determination of the position and/or orientation of a vehicle (10) to be located, which is designed for communication in a wireless communication network, wherein broadband pulses of short duration are transmitted from the vehicle (10) to surrounding fixed stations (31 - 35), which are answered by the surrounding fixed stations (31 - 35) in an immediate return of a response pulse when received, wherein a measurement of the transit time of the emitted pulse until the arrival of the return pulse from at least one of the surrounding fixed stations (31 - 35) is carried out in the vehicle (10), wherein a respective transmission of a pulse takes place one after the other by a number of antenna elements (176) mounted at different positions of the vehicle (10) with a respective transceiver, wherein for each mounted antenna element (176) a transceiver (170) is located in the vicinity of a position of the antenna element (176) and a communication module (110) with the Transceivers (170) of the antenna elements (176) mounted at the various positions, wherein the communication module (110) is designed to request the various transceivers (170) one after the other to transmit the broadband pulse of short duration or to assign them respective planned times for the successive transmission of the broadband pulses, and the time until the respective response pulse arrives at the individual antenna elements (176) is measured by means of the respective transreceiver (170), wherein the determination of the positions of the antenna elements (176) of the vehicle (10) to be located is carried out in each case based on at least one intersection calculation with the resulting at least three travel times and the known positions of the antennas of the fixed stations (31 - 35) and the position and/or orientation of the vehicle (10) is determined from the determined antenna element positions (176) on the vehicle (10) is determined, wherein the antennas of each fixed station (31 - 35) are designed in the form of antenna arrays (310) which consist of a number of antenna elements (31A, 31B, 31C, 31E), wherein a single antenna element (31E) is used for the return in order to radiate the response pulse, wherein three different transit time measurements are carried out one after the other with three different individual antenna elements (31A, 31B, 31C) of the antenna array (310), wherein the individual antenna elements (31A, 31B, 31C) are selected such that they are as far apart from one another as possible.

Description

The invention relates to a method for the highly accurate determination of the position and/or orientation of a vehicle to be located. The proposal also relates to a device for the highly accurate determination of the position and/or orientation of a vehicle to be located and a base station for a mobile radio communication system.

For the scenario of vehicles equipped with radio communication modules that communicate directly with each other in public traffic, be it for cooperative or autonomous driving, or for participation in mobile communications and connection to the Internet or the provision of other data services, a high level of reliability in safety-critical applications is essential or very important for the customer.

Navigation aids have become a part of many people's everyday lives. In both rural and urban areas, they help people to reach specific locations and minimize the time needed to get there. In vehicle applications in particular, satellite navigation is generally used, which incorporates information from signals from other vehicle sensors to increase robustness. Satellite navigation is known as GNSS, or Global Navigation Satellite System.

In densely built-up areas, however, satellite navigation reaches its technical limits, as the satellite signals in narrow urban canyons often cannot be received directly, but only indirectly after (multiple) reflections on house walls. The satellite-based localization result is thus sometimes so distorted that it is at least temporarily unsuitable for correcting the position estimate from the (less accurate) vehicle sensor signals.

The localization task is even more difficult inside buildings. Since satellite signals generally do not penetrate ceilings and walls, a method must be developed for indoor navigation applications that does not require any satellite signals at all. This requires significantly higher accuracy requirements than outdoor navigation. While this is necessary for autonomous driving of a vehicle in a parking garage, the most important vehicle application, in order to avoid collisions with other vehicles or parking garage obstacles, for the electronic museum guide, a typical non-vehicle application, there is a risk of navigating the user to the wrong room even if the accuracy is several meters.

A non-satellite-based alternative for indoor localization is the field strength of the WLAN network that is often already in place. The signal must be measured using the end device, e.g. an additional unit of the vehicle navigation system or the electronic museum guide, and compared with maps of the characteristic field strength distribution of the WLAN network. Location determination via the earth's magnetic field, which is significantly changed by building properties, is also based on this principle. The effort required to create and continuously update the field strength maps is, however, high, especially given the high accuracy requirements.

Another possibility is to install small transmitters inside a building that transmit Bluetooth Low Energy signals (BLE signals), for example. The location can then be determined using trilateration: the signals from three transmitters are used to determine their respective distances from the end device, and the position is determined using the known transmitter locations and the determined distances by calculating the intersection point. To measure the distance, similar to radar technology, time-of-flight measurements can be carried out on transmitted signals that are reflected back or immediately re-transmitted by the transmitter when a measurement signal from the vehicle arrives. Another possibility is to measure the field strength, whereby the distance to the transmitter can also be determined using a correspondingly accurate map of the field strength distribution for a standard transmission.

An example of a positioning system based on GPS signal evaluation is in US2004/0193372 A1 also described for the platooning application. The GPS system is improved by combining it with Bluetooth. Position information is exchanged with a vehicle in the platoon via a Bluetooth connection. During operation, the vehicles communicate satellite data via the Bluetooth connections. This makes it possible to use the Bluetooth radio connections to reduce the number of satellites required for the GPS system without losing the accuracy of the measurements. The possibility of using UWB communication as an alternative to Bluetooth communication is pointed out.

Another example of such a system is in US 2015/0269845 A1 Here, particular emphasis is placed on the need for high-quality The precise synchronization of the clocks in the vehicles is pointed out in order to measure the exact position of the vehicles using runtime measurements. The use of high-precision clocks in the GNSS systems is suggested as a solution.

From the DE 10 2015 122 145 A1 A method for improved position determination of a mobile station or a handset within a mobile radio network is known. The method comprises the steps of: transmitting at least three radio signals between the mobile station and a corresponding number of at least three base stations, wherein at least each of the three radio signals comprises temporal information indicating a transmission time of the corresponding radio signal; calculating a time delay for each of the at least three radio signals on the basis of a difference between an arrival time and the transmission time of the corresponding radio signal; retrieving the information for each of the at least three radio signals about the transmission path losses of the corresponding radio signal from a data memory; calculating a distance of the mobile station from the corresponding base station for each of the at least three radio signals based on the time delay and the information about the transmission path losses; and determining a location of the mobile station based on the trilateration of the at least three distances.

From the US 2019 066 504 A1 is a ground-based radio system called Autonomous Transceivers Positioning System ("ATPS") that performs complete autonomous tracking of multiple moving objects and determines the position and velocity components (speed and direction) of a moving object or the stationary position of an object. For a moving object, the system provides position determination with an accuracy of several centimeters and velocity determination with an accuracy of centimeters per second. The ATPS system tracks the position of multiple objects simultaneously and continuously as long as the objects are within the working area of the wireless ATPS system. The ATPS includes RFID-inspired components including advanced autonomous wireless interrogators with multiple fixed locations within the system's defined working area and multiple autonomous wireless responders attached to moving and/or stationary objects.

In the WO 2019 143 437 A1 describes positioning techniques that enable the localization of a target user equipment (UE) in a wireless communication network that is served by one (or a number of) different radio access technologies (RATs). The techniques include field strength measurements, time-of-flight measurements and angle measurements.

Due to the wavelength of the WLAN and BLE signals of approximately 12.5 cm, corresponding to a frequency of 2.5 GHz, localization with sufficiently high accuracy is possible in principle. Since the permitted WLAN and BLE transmission power is high enough to achieve interference-free or interference-minimal information transmission even with larger antenna distances and thus acceptable system costs, it must be assumed for indoor navigation applications that the WLAN and BLE signals cannot be received directly from every point, but only indirectly after (multiple) reflections on walls and obstacles. The localization accuracy theoretically possible with a wavelength of 12.5 cm can only be approximately achieved under these conditions if the (multiple) reflections are compensated for using dedicated calculation models. On the one hand, these calculation models are very complex and therefore time-consuming to develop; on the other hand, they must be continuously kept up to date in order to take into account possible structural changes to the building during system operation over several years.

The work required for this is eliminated when the antenna density is increased, so that the WLAN and BLE signals can largely be received directly and the proportion of (multiple) reflections is reduced. Generic models are therefore sufficient to compensate for them in indoor localization, which are on the one hand simpler and on the other hand no longer need to be continuously updated.

For indoor navigation applications with particularly high accuracy requirements, it may be necessary to extend the trilateration method described above to include an ultra-wide-band approach (UWB approach). The principle of this approach is to send out a very limited time pulse with a duration of <1ns and a very pronounced edge steepness corresponding to a bandwidth of several hundred MHz from a transmitter of an autonomous vehicle or an electronic museum guide, for example. Due to the principle, the radiated power of a UWB pulse is distributed over the very large bandwidth. This results in only a slightly increased radiated power per bandwidth interval, so that the limit of the specific radiated power of another type of communication emitted by the same station is practically not exceeded by the additional UWB emission in the respective interval.

Despite the low power of the UWB pulse, receivers distributed indoors must be able to detect the UWB pulse correctly and send a response back to the transmitting device. The distance between the receivers distributed indoors must therefore not exceed a maximum value that depends on the given boundary conditions and should ideally be chosen so that there is visual contact with at least three receivers from every point in the indoor area. The reason for this requirement is the need to be able to detect and ignore reflections. If there is no direct visual contact, only reflected signals or even multiple reflected signals would be present. In order to be able to determine the distance between transmitter and receiver from this, complex calculation models would be required. These models would always have to be kept up to date in order to be able to reflect any structural changes. If there is a direct line of sight between transmitter and receiver, it is possible to detect and ignore reflections and multiple reflections. The distance calculation can then be determined with high accuracy based on the direct pulse transit time.

Under these conditions, by precisely measuring the time between the transmission of the original pulse and the arrival of the reflected pulse by at least three receivers, it is possible to determine the distances between the terminal device and the transmitters and to determine the terminal device position using the transmitter locations and the distances.

The pronounced synchronization of currently available electronic clocks makes it possible to keep the error of the determined position < 1 cm. The advantage of this high accuracy is offset by the disadvantage of the high costs due to the large number of receivers required to reflect the transmitted pulses.

From the US 2019/0361109 A1 A detection system emerges which is primarily used in an industrial environment in a building. The system of a tracking device can also be used in vehicles, for example in urban areas or where localization using GNSS is not possible. The tracking device provides localization in which the position of a moving object relative to a transmitter or vice versa is determined using a first and a second reference signal, each dependent on a transmission or reception signal. According to one example, the device comprises the measurement of a "direct time of flight (TOF) using at least one transmitter and at least one receiver. Another example provides that increased localizability is made possible by using an interrogation transmitter with three antennas and four channels, whereby here too the three antennas have direct contact with the transponder. Two or three receivers assigned to the interrogation transmitter receive the signal emitted by the transponder and enable hyperbolic or triangular determination of the transponder and thus of the object.

The invention aims to find a method for highly accurate self-localization for vehicles, in particular vehicles moving inside buildings.

This object is achieved by a method for determining the position and/or orientation of a vehicle to be located according to claim 1, a device for determining the position and/or orientation of a vehicle to be located according to claim 7 and a base station for a mobile radio communication system according to claim 12.

The dependent claims contain advantageous developments and improvements of the invention according to the following description of these measures.

The solution to the problem is a method for highly accurate determination of the position and/or orientation of a vehicle that is designed for communication in a wireless communication network. This can be implemented in the form of a mobile radio communication network. For highly accurate position and/or orientation determination, the vehicle sends out broadband pulses of short duration to the surrounding fixed stations, which are responded to immediately by the surrounding fixed stations when received. For accurate position and/or orientation determination, a measurement of the transit time of the emitted pulse until the response pulse of the return is received from one of the surrounding fixed stations is carried out in the vehicle. The pulse is repeatedly emitted one after the other by a number of antenna elements attached to different positions on the vehicle, and the transit time from and to the individual antenna elements is measured. The transit time is used to determine the position of the antenna element of the vehicle based on the measured transit times and the known positions of the fixed stations. An intersection point calculation is carried out. If measurement results are available for three different fixed stations, the Intersection calculation of a trilateration calculation. If more measurement results are available, the intersection calculation can be carried out in the form of a multilateration calculation. The position of the antenna elements is calculated based on the position of the intersection points. Theoretically, it is possible for two returns from different fixed stations to arrive at the vehicle at the same time. If there is an interference here, the measurement must be repeated. If the vehicle is moving, then different conditions will quickly arise so that the interference is eliminated.

The broadband pulses of short duration can, in a preferred variant, correspond to ultra-wide-band pulses (UWB). These are pulses that are emitted in the UHF or SHF frequency band. They are particularly suitable for distance measurement. The UWB pulses have a high bandwidth of around 500 MHz or more, which means they last a short time in the time range of a few or fractions of nanoseconds. UWB pulses are therefore also used for distance measurement, but only for short distances, since they are emitted with only a small amount of radiation energy and the range is accordingly limited.

For the method, it is planned that the antennas of the fixed stations are designed in the form of antenna arrays consisting of a number of antenna elements, whereby a number of antenna elements radiate the measuring pulse in parallel for the time of flight measurement or a single antenna element is used to radiate the measuring pulse. The 5G antennas for the so-called 26 GHz frequency band are particularly suitable for use in the measurement method. Their widespread implementation is expected as soon as the current rollout of 5G telecommunications technology for the 3.5 GHz frequency band is completed. In the 26 GHz band, the propagation conditions are worse than in the frequency ranges up to 10.6 GHz, since the radio signals in this frequency range are subject to a particularly high level of attenuation. Therefore, a reduction in the distance between the fixed stations is necessary, which allows line of sight to be established more frequently and reduces the problem of multiple reflections.

Three different runtime measurements are carried out one after the other with three different individual antenna elements of the antenna array in the fixed stations, with the individual antenna elements being selected so that they are as far apart as possible from each other. These three individual measurements provide results for three different positions of three different antenna elements. Carrying out the runtime measurements one after the other is advantageous because in this case only one antenna element needs to be present in the remote station (here the vehicle). This results in cost advantages. However, if not only the position of the vehicle but also its orientation, for example in the form of the yaw angle, is to be determined, several antenna elements are required, e.g. in the form of individual antenna elements that are further apart in the remote station (here the vehicle).

The position of the vehicle-side antenna element(s) can then be calculated using trilateration calculations based on the transit time measurements for the three antenna elements of the antenna array of the base station. However, the accuracy of the position determination also depends on the distance between the antenna elements of the antenna array(s).

Here it is also advantageous if, when the response pulses from two or more different surrounding fixed stations arrive at an antenna element of the vehicle, the position determinations of the antenna element of the vehicle to be located are averaged. This can further increase the accuracy of the position determination.

It is also advantageous if the transit time measurements from the various antenna elements of the vehicle for the pulse sent back from a fixed station are subjected to a plausibility check, whereby a transit time that was rejected as incorrect during the plausibility check is not used for the intersection calculation. This prevents a transit time measurement with a larger error from worsening the accuracy of the position determination. In certain circumstances, it is possible that a measurement pulse is reflected by obstacles and does not return directly to an antenna. In this case, the transit time measurement no longer corresponds to the direct distance measurement between the object vehicle and the fixed station and is therefore falsified.

In one variant, the plausibility check is based on a comparison of the measured runtimes, taking into account the local proximity of the antenna elements attached to the vehicle, and those runtimes whose runtime does not correlate with the local proximity of the antennas are rejected as incorrect. In other words, the plausibility check takes advantage of the fact that there will be a runtime measurement based on direct reception. If other runtime measurements deviate significantly from this beyond the known distance from the vehicle's antennas, it is assumed that they are due to reflections. reception. These are then discarded as faulty.

By weighting the runtime measurements depending on the results of the plausibility check, the accuracy of the position determination can also be increased.

Finally, according to the method, the position and orientation of the vehicle is determined from the determined antenna element positions on the vehicle. In a vehicle, the vehicle position and/or orientation is required for a variety of purposes. Among other things, for navigation purposes. But even if the vehicle is equipped with an automatic driving function, the position and/or orientation information is essential to avoid a collision with an obstacle or another road user. But even if the vehicle is not a vehicle, for example a pedestrian, the accuracy of the position and/or orientation determination is just as important so that navigation works, especially inside buildings.

A particularly advantageous variant of determining the position and/or orientation of the vehicle is achieved by using a trilateration calculation or multilateration calculation based on the runtime measurements of an antenna element attached to the vehicle for the pulses sent back from three or more different fixed stations. This allows the position to be determined to within a few centimeters and the orientation to within less than 10°. Here, the distances between the fixed stations are large enough to carry out the trilateration with high accuracy. The smaller the distances between the fixed stations, the more errors in the runtime measurement affect the position and/or orientation determination.

In another embodiment, the invention also relates to a corresponding device for determining the position and/or orientation of a vehicle to be located. The device is equipped with a communication module for communication in a wireless communication network. The device is also equipped for communication with the surrounding fixed stations of the communication network. The device is characterized by a number of antenna elements attached to the vehicle at different positions, with one transceiver being provided for each attached antenna element, which is located close to the position of the antenna element. The advantage of positioning it close to the antenna element is that only short connecting lines are required between the antenna element and the transceiver. This is necessary in order to avoid falsifying the transit time measurements as much as possible. The transceiver is used to generate a broadband pulse of short duration, which is emitted by the antenna element to the surrounding fixed stations and to receive a response pulse sent out by the surrounding fixed stations by direct return. It is also used to measure the transit time of the emitted pulse until the response pulse arrives from one of the surrounding fixed stations. The pulse is transmitted by the various antenna elements that are mounted at different positions on the vehicle, and the transit time is measured by the transceivers assigned to the individual antenna elements. With this arrangement, the position and/or orientation of the vehicle can be determined very precisely using common methods for calculating intersection points, in particular trilateration or multilateration.

The communication module is connected to the transceivers of the antenna elements located at the various positions, and the communication module is designed to request the various transceivers to transmit the short-duration broadband pulse one after the other or to assign them respective scheduled times for the sequential transmission of the broadband pulses. This is necessary to avoid interference between the pulses. This is because the danger arises when the pulses are transmitted by different antennas at the same time.

It is also advantageous if the communication module is also designed for communication in a mobile network and is set up to send an announcement message for the position and/or orientation determination measurement phase to the surrounding fixed stations, with which the arrival of a broadband pulse is announced and the fixed stations are requested to respond to the incoming pulse by immediately returning the response pulse. Only if the response pulse is sent immediately can the transit time measurement be calculated directly by forming the difference between the time of transmission of the measurement pulse and the time of arrival of the response pulse.

In addition, it is advantageous if the base stations are requested with the announcement message to transmit their identification to the communication unit in a further pulse or a further pulse sequence or in a message via a logical channel of the wireless communication system.

In a further embodiment, the invention also relates to a vehicle, wherein a device according to the invention is installed in the vehicle.

Finally, in a further embodiment, the invention also relates to a base station for a mobile radio communication system with an antenna arrangement and with a transmitting and receiving unit. The transmitting and receiving unit is designed to receive an announcement message for the position and/or orientation determination measurement phase of a vehicle to be located and, in response to the receipt of the announcement message, to switch to an operating mode in which the arrival of the short-duration broadband pulse is waited for and, upon receipt of the pulse, the response pulse is immediately sent back.

Furthermore, it is provided that the transmitting and receiving unit is designed to receive another announcement message, which puts the base station into another operating mode in which it determines three antenna elements of the antenna array, which each send a response pulse back to the vehicle for separate transit time measurements when the broadband pulse arrives. The transit time measurements take place one after the other.

An embodiment of the invention is shown in the drawings and is explained in more detail below with reference to the figures.

• 1 das Prinzip der Fahrzeugkommunikation über Mobilfunk;
• 2 die Sichtlinienverhältnisse zwischen in Abständen von 50 - 100 m angebrachten Feststationen eines Mobilfunkkommunikationssystems in einem ruralen Bereich;
• 3 die Sichtlinienverhältnisse zwischen in Abständen von 50 - 100 m angebrachten Feststationen eines Mobilfunkkommunikationssystems in einem urbanen Bereich;
• 4 die Sichtlinienverhältnisse zwischen in Abständen von 30 - 50 m angebrachten Feststationen eines Mobilfunkkommunikationssystems in einem Parkhaus;
• 5 ein Beispiel einer Antennenanordnung in Form eines Antennen-Arrays wie sie in einer Feststation eines 5G-Mobilfunksystems eingesetzt werden;
• 6 ein Beispiel einer Antennenanordnung und der zugehörigen Transceiver bei einem Fahrzeug;
• 7 ein Blockdiagramm für die Fahrzeugelektronik eines Kraftfahrzeuges;
• 8 ein erstes Beispiel der Sichtlinienverhältnisse von einem Fahrzeug zu mehreren umliegenden Feststationen in einem Parkhaus; und
• 9 ein zweites Beispiel der Sichtlinienverhältnisse von einem Fahrzeug zu mehreren umliegenden Feststationen in dem Parkhaus.

They show:

• 1 the principle of vehicle communication via mobile communications;
• 2 the line of sight conditions between fixed stations of a mobile radio communication system installed at intervals of 50 - 100 m in a rural area;
• 3 the line of sight conditions between fixed stations of a mobile radio communication system installed at intervals of 50 - 100 m in an urban area;
• 4 the line of sight conditions between fixed stations of a mobile radio communication system installed at intervals of 30 - 50 m in a parking garage;
• 5 an example of an antenna arrangement in the form of an antenna array as used in a base station of a 5G mobile radio system;
• 6 an example of an antenna arrangement and the associated transceivers in a vehicle;
• 7 a block diagram for the vehicle electronics of a motor vehicle;
• 8 a first example of the line of sight conditions from a vehicle to several surrounding fixed stations in a parking garage; and
• 9 a second example of the line of sight conditions from a vehicle to several surrounding fixed stations in the parking garage.

The present description illustrates the principles of the inventive disclosure. It is therefore to be understood that those skilled in the art will be able to devise various arrangements which, although not explicitly described herein, embody principles of the inventive disclosure and are also intended to be protected within their scope.

1 shows the principle of vehicle communication via mobile radio. The vehicles are provided with the reference number 10.

The term vehicle is a collective term, whether for motor vehicles with internal combustion engines or electric motors, for bicycles with and without electric motors or other vehicles powered by human power, e.g. wheelchairs, for vehicles with one, two, four or more wheels, for motorcycles, passenger cars, trucks, buses, agricultural vehicles or construction machinery. The list is not exhaustive and also includes other vehicle categories. These also include aircraft, watercraft or rail vehicles.

The vehicles in 1 are each equipped with a so-called on-board unit 110, which serves as a communication module for a mobile radio communication system. This on-board unit 110 corresponds to a mobile radio network subscriber station in the sense of the disclosure of the invention. Examples of public mobile radio networks are the already mentioned mobile radio communication systems LTE and 5G. In these mobile radio communication systems, the typical mobile radio network subscriber stations are referred to as UE, corresponding to user equipment. In the case shown, the on-board unit 110 is also a fully-fledged mobile radio network subscriber station in a passenger car. All messages from the vehicles (uplink) and to the vehicles (downlink) are either routed via a mobile radio base station 30, which serves a mobile radio cell, or in the case of direct vehicle communication (sidelink), exchanged directly between the vehicles. If the vehicles 10 are within this mobile radio cell, cell, they are registered or logged in at the base station 30. If they leave the cell, they are transferred to the neighboring cell (handover) and accordingly deregistered or logged out at the base station 30. The base station 30 also provides access to the Internet, so that the vehicles 10 or all other mobile phone subscribers in the cell are supplied with Internet data. For this purpose, the base station 30 is connected to the EPC 40 (Evolved Packet Core) via the so-called S1 interface. Central computers 50 or generally the servers of a service provider can also be reached via the Internet 300 or another wide area network WAN.

Such mobile communications technologies are standardized and reference is made to the relevant specifications of mobile communications standards.

LTE stands primarily for high transmission rates and short response times. At the moment, a lot of work is being done on the newer 5G mobile communications standard. This should be much more flexible for different applications. Some keywords for the newer applications are Internet of Things (loT), Industry 4.0, vehicle-to-vehicle communication for autonomous or cooperative driving. The 5G mobile communications system should provide the data connection for all of these applications. This is only possible if there is a massive network expansion. This will also improve communication within buildings in particular.

As with LTE, the transmission speed of 5G depends essentially on the frequency range, the channel width, the distance to the base station 30 and the number of participants within the cell. The more users use the bandwidth at the same time, the lower the transmission rate per participant. However, prioritization can be made for paid services and more work is being done with Quality of Service (QoS), which can reserve bandwidth for specific applications. For the 5G mobile communications system, too, reference is made to the various specifications for the exact details of the 5G standard. These can be accessed at the Internet domain www.3gpp.org.

As with LTE and 5G, OFDMA (Orthogonal Frequency Division Multiple Access) technology is used for the downlink. This uses the well-known multi-carrier transmission technology OFDM (Orthogonal Frequency Division Multiplexing), in which data symbols are modulated onto the individual carriers using QPSK (Quadrature Phase-Shift Keying) or QAM (Quadrature Amplitude Modulation). With OFDMA, the available frequency band is divided into many narrow bands (channels). The bandwidth is used flexibly to get the maximum transmission power out of the frequencies.

Special algorithms select the appropriate channels, taking environmental influences into account. Preferably, only the carriers that are most suitable for the user at his or her location are used for transmission.

SC-FDMA technology (Single Carrier Frequency Division Multiple Access) is used for the uplink. This is a single carrier access method that is otherwise very similar to OFDMA. SC-FDMA has lower power fluctuations and enables simpler power amplifiers. This saves battery life, especially in mobile devices.

Uplink communication resources are also used for vehicle-to-vehicle communication.

A new frequency band is made available for 5G in the 26 GHz range. Due to the pronounced attenuation of radio waves in the 26 GHz frequency band by the atmosphere, it is necessary to implement the corresponding 5G antennas at a distance of < 50-100m. This is the only way to ensure that the telecommunications signals are sufficiently attenuated during transmission between the 5G terminal and the 5G antennas in rural areas with the greatest possible direct line of sight to the 5G antennas. 2 shows the distance between the 5G base stations in rural areas and the 3 the distance between 5G fixed stations in urban areas.

In urban areas, there is also the fact that direct line of sight between 5G antennas and telecommunications terminal devices only exists if the distance between 5G antennas is < 50-100 m from most points.

Inside buildings, however, an even higher density of 5G antennas and thus a distance of 30 - 50 m is required to achieve direct line of sight between 5G antennas and subscriber terminals UE, see. 4 .

This small distance between the 5G antennas for the 26 GHz range, which already exists for telecommunications, can be used for highly precise self-localization of the subscriber stations. Another particular advantage is that the 5G antennas for telecommunications are actually antenna arrays with a large number of elements. Such an antenna array 310 is in the 5 For an element dimension of e.g. 2cm × 2cm For an antenna array 310, the result is 5 a base area of 12cm × 12cm. The reason for using such antenna arrays in 5G is that 5G should also support the use of beam steering technology.

Antenna arrays with such dimensions can be easily installed in rural areas, e.g. along roads, railways and waterways, but also in urban areas and inside buildings and parking garages according to the 2 , 3 and 4 It is more difficult to use such antenna arrays in vehicles 10 or more generally in mobile vehicles. However, so-called 5G single-element antennas are already available, such as those offered by the consortium of NTT DOCOMO, AGC and Ericsson with dimensions of 1cm × 1.5cm. Such an element is available in the 5 also shown.

According to one aspect of the invention, such individual antenna elements are installed at several locations in the vehicle 10 in order to enable highly precise self-localization. This is required for autonomously driving vehicles, assisted driving vehicles or cooperatively driving vehicles. Highly precise self-localization is also required for navigation within buildings, such as parking garages.

For this purpose, the vehicles 10 are each equipped with at least one 5G single-element antenna 176 on the front, rear and side windows of the vehicle. Each single-element antenna is connected to a transmitting and receiving unit 170 in the vicinity of the antenna. The transmitting and receiving unit is referred to below as a transceiver. The various transceivers are networked with each other. In addition, they are networked with the on-board unit 110. The components and their networking are shown in the 6 The installation of the transceiver 170 near the antenna is necessary in order to be able to emit the measuring pulse, which is limited to <1ns, with the required extreme edge steepness. 6 shows the special form of networking in the form of a linear communication bus. As an example, a variant of the CAN bus, corresponding to Controller Area Network, can be used. The CAN bus meets the requirements in terms of data rate and short latency by using the bus access method CSMA-CA, corresponding to Carrier Sense Multiple Access - Collision Avoidance.

The embedding of the antenna arrangement in the overall system of the on-board electronics is shown in the block diagram of the 7 shown.

7 shows a typical structure of on-board electronics 100 of a modern motor vehicle 10, in which a device according to the invention for highly precise self-localization is also present. The reference number 151 designates an engine control unit. The reference number 152 corresponds to an ESP control unit and the reference number 153 designates a transmission control unit. Other control units such as airbag control units, etc. can be present in the motor vehicle. The networking of such control units typically takes place with the CAN bus system (Controller Area Network) 104, which is standardized as an ISO standard, ISO 11898. Since various sensors are installed in the motor vehicle and are no longer only connected to individual control units, such sensor data is also transmitted to the individual control units via the bus system 104. Examples of sensors in the motor vehicle are wheel speed sensors, steering angle sensors, acceleration sensors, yaw rate sensors, tire pressure sensors, distance sensors, etc. The various sensors with which the vehicle is equipped are listed in the 7 designated by the reference numbers 161, 162, 163.

However, the modern motor vehicle can also have other components such as video cameras, e.g. as a rear view camera or as a driver monitoring camera or even as a front camera to observe traffic.

For several years now, driver assistance systems have been available that use radar, lidar or video sensors to record the driving environment, create an internal representation of the driving situation by interpreting this sensor data and, based on this knowledge, carry out increasingly sophisticated functions by informing and warning the driver and even making targeted interventions in the vehicle's control. For example, longitudinal control on well-structured roads such as motorways can be carried out automatically for a large proportion of the time by an ACC system (Adaptive Cruise Control) equipped with lidar and/or radar sensors. With this and other precautions, even fully automated vehicles can be realized.

There are also other electronic devices in the vehicle. These are located more in the passenger compartment and are often operated by the driver. Examples include a user interface device (not shown) with which the driver can select driving modes, but also operate classic components. These include gear selection as well as indicator control, windshield wiper control, light control, etc.

This is often distinguished from a navigation system 120, which is also installed in the cockpit area. The route, which is shown on a map, can be shown on a display in the cockpit. The reference number 110 also designates an on-board unit. This on-board unit 110 corresponds to a communication module via which the vehicle 10 can receive and send mobile data. As described, this can be a mobile communications module, e.g. according to the 5G standard.

The devices in the passenger compartment are also networked with each other via a bus system, which is designated with the reference number 102. This can be, for example, the high-speed CAN bus system according to the ISO 11898-2 standard, but here in the variant for data transmission with a higher data rate between infotainment devices. Alternatively, Ethernet is also used for networking components in the vehicle. The gateway 140 is provided for the purpose of transmitting vehicle-relevant sensor data via the communication module 110 to another vehicle or to another central computer. This is connected to the various bus systems 102, 104. The gateway 140 is designed to convert the data it receives via the CAN bus 104 in such a way that it is converted into the transmission format of the high-speed CAN bus 102 so that it can be distributed in the data packets specified there. In order to forward this data externally, the communication module 110 is equipped to receive these data packets and convert them into the transmission format of the communication standard used. To implement the highly precise self-localization, the on-board electronics are equipped with 6 The transceivers 170 are provided at the locations shown, to which the antenna elements 176 are connected with a short antenna cable. In the example shown, four 5G antenna elements 176 with the associated transceivers 170 are provided. The transceivers 170 are connected to the high-speed CAN bus 102.

During the journey, the individual transceivers 170 can exchange messages with the navigation system 120 and the on-board unit 110 via the CAN bus 102. The application, which is considered here as one of many embodiments, corresponds to the implementation of a highly accurate navigation system 120 that can also be used for navigation within buildings. The problem in parking garages is that they are often overcrowded and it is difficult for drivers to find a free parking space. Parking garages are often very winding and spread over several levels. This can lead to vehicles driving in to cover long distances in search of a free parking space. This is a waste of resources, leads to more exhaust fumes in the city and also leads to dissatisfaction among those looking for a parking space. An intelligent navigation system is intended to remedy this. This can receive information about the locations of free parking spaces in the parking garage via the Internet connection from the parking garage server 50. It can also load the detailed map for route guidance in the parking garage from the server 50. The navigation system 120 can then guide the vehicle 10 to the free parking space. However, this requires highly precise self-localization.

The process of highly accurate self-localization is now being carried out using 8 and 9 explained. For this purpose, the transceivers 170 are requested one after the other to send out the time-limited measuring pulse with a pronounced edge steepness via the CAN bus 102 by a coordination unit 172 integrated in the on-board unit 110. This measuring pulse is generated in the respective transceiver 170 using the ultra-wide band radio technology developed for short-range radio. The Federal Network Agency has currently approved some frequency ranges in the SHF range of interest here. These are ranges between 3.1 and 10.6 GHz. The 26 GHz range newly approved for 5G communication would also be interesting, and is expected to be approved for UWB communication in the future. The transmission power is very low at 0.5 mW / -41.3 dBm/MHz. Since this transmission power is distributed over a bandwidth of 500 MHz, there is practically no interference with other radio systems. The range with these key data is 10 - 50 m. With a distance of 30 - 50 m between the 5G fixed stations distributed in the parking garage, it would be necessary to design the UWB communication for a range of 50 m, which is possible by adjusting the transmission power.

Before the UWB measurement pulses can be transmitted, a defined announcement message is first sent via 5G communication to the control units of the 5G fixed stations with visual contact to the vehicle-side antenna elements 176, with which the respective fixed station is switched to a special operating mode in which it waits for the arrival of UWB measurement pulses from a number of antenna elements that are as far apart as possible in order to then send them back immediately to the respective antenna element. Following this, the identifier of the respective fixed station is then additionally sent to the vehicle via a UWB pulse sequence sent directly afterwards, picked up by the antenna element 176 in the vehicle 10 at which the measurement pulse was transmitted, from the associated transceiver 170 evaluated and forwarded to the on-board unit 110 together with the measured value for the measured runtime. In the simplest case, the individual bits of the identifier can be transmitted with the pulse sequence by sending a pulse or skipping a pulse as coding for the bit states. Alternatively, it is possible to transmit the identifier following the UWB measurement via a logical channel of the mobile radio system. Here, the 5G mobile radio system, like LTE, offers various logical channels. One example is the logical channel PHICH (Physical Hybrid Indicator Channel) of the 5G mobile radio system, on which confirmations that were previously sent to the base station are transmitted.

The transceiver 170 functions in such a way that after the transceiver 170 has sent out the measuring pulse via the connected vehicle-side antenna 176, the transceiver 170 checks over a predetermined, limited period of time to see whether immediately returned pulses are arriving. If so, it determines the pulse runtime. After the assignment to the identifiers of the fixed antenna array of the base station 31 - 35 that are sent along with the transmission of the response pulse and the respective processing time for sending the response pulse after receiving the input pulse, the processing time is first subtracted from the difference between the times for sending the measuring pulse and receiving the response pulse and the result is divided by two to determine the runtime for the simple distance. The transit time measurement values and the associated fixed station identifiers are then forwarded to the on-board unit 110 via the CAN bus 102. If there is no visual contact between the vehicle-side antenna 176 and the antenna array 310 of a fixed station 31 - 35, the on-board unit 110 is alternatively informed that no response pulses have arrived within the specified, limited period of time. The case of a response pulse not arriving within a limited period of time occurs when the vehicle-side antenna 176 is outside the reception range of the antenna array of the fixed station 31 - 35 and/or the antenna array 310 of the fixed station 31 - 35 is outside the reception range of the vehicle-side antenna element 176.

After the information from all vehicle-side antenna control units 170 has arrived, the vehicle-side on-board unit 110 first estimates the distance between the vehicle-side antenna elements 176 and the antenna arrays 310 of the fixed stations in the reception area from the transmitted pulse transit times before identifying, taking into account the known locations of the antenna arrays 310, as part of a plausibility check, which distance values result from multiple reflections. After eliminating these distance values resulting from multiple reflections, the vehicle-side antenna positions are then calculated using trilateration or multilateration on the basis of the remaining distance values from measurements via direct visual contact. The vehicle position and/or orientation is then calculated from the calculated antenna positions on the vehicle 10.

The 8 shows a level of a parking garage with many parking spaces. Some blocked areas are shown filled in, which are occupied by walls, pillars or other structural features. Some 5G fixed stations 31 - 35 with their 5G antenna arrays are distributed on the parking level. The structural features but also other parked vehicles can cause shadows, so that the UWB measurement signals emitted by the antenna elements 176 on the vehicle 10 do not have a direct line of sight to the antenna arrays of the fixed stations 31 - 35. This is shown by dashed lines in 8 Thus, with a corresponding 8 positioned vehicle 10, the vehicle-side windshield and the right-hand side window antenna element 176 have visual contact with the antenna array 310 of the fixed station 31, whereas the left-hand side window antenna element 176 has no visual connection to the antenna array 310 of the fixed stations 31. There is also no direct visual connection to the 5G fixed stations 32, 33, 34 for all vehicle antenna elements 176. There is also no visual connection to the fixed station 35. But that would be the case even if there were no blocked area in the way, because the fixed station 35 is no longer within range of the emitted pulse. Only the antenna elements 176 on the windshield and left and right side windows will therefore report pulse transit times, while the rear window antenna element cannot receive any reflected response pulses.

The antenna element on the left side window may report a pulse runtime, as it has no direct, but indirect visual contact. This is in the 8 indicated by the dashed line, which first leads from the vehicle 10 to the adjacent closed area and from there in the direction of the antenna array of the fixed station 31. 8 It is clear that the transit time measurement reported by the antenna element 176 on the left side window will provide a value that is too high because the signal path is significantly longer than for the other two antenna elements 176. Therefore, a plausibility check takes place in the coordination unit 172 of the on-board unit 110. The plausibility check can be carried out in a variant in The test can be carried out by comparing the pulse transit times reported by the left and right side window antennas. The comparison is made against a tolerance value. If a measured value deviates from the measured value of the antenna element 176 of the other side window by more than the specified tolerance value, the measurement is identified as faulty and discarded.

The position and/or orientation of the vehicle is then determined using the remaining two antenna elements according to the measuring method according to the invention. When using the measuring method according to the invention, the antenna element 176 for which no direct visual contact was identified is omitted. However, this means that the minimum required number of three antenna elements 176 for the trilateration is not reached. To remedy this, the measuring method according to the invention is used for this case. The measurement is then carried out again according to the method according to the invention. The antenna array 310 of the fixed station is used differently. Three antenna elements are selected from the antenna array 310 that are as far apart from each other as possible. In 5 the positions of the selected antenna elements are marked. They are designated with the reference symbols 31A, 31B, 31C. Three transit time measurements are carried out one after the other with these three antenna elements 31A, 31B, 31C. Since the positions of these three antenna elements 31A, 31B, 31C differ, the transit times will also differ. A trilateration calculation can then be carried out with the results in order to calculate the positions of the vehicle antenna elements 176. From this, the position and/or orientation of the vehicle 10 can then be determined. In order to carry out the inventive method, it is necessary to initiate this operating mode. For this purpose, an announcement message is sent to the fixed station in which the inventive operating mode is announced. In order to avoid falsification of the pulse transit times when estimating the position of these two vehicle-side antennas, it is necessary to wait for the pulse to be reflected after it has been transmitted by one of the two vehicle-side antennas before the next pulse is transmitted by the other of the two antennas.

The 9 shows the line of sight conditions for a different position of the vehicle 10 on the parking plane shown. The same reference numbers designate the same components as in 8 . In the 9 In the position of the vehicle 10 shown, the windshield and left side window antennas have visual contact with both the antenna array of the fixed station 31 and the fixed station 32. In addition, the antenna array 310 of the fixed station 35 has both lateral visual contact with the rear window antenna element 176 and almost frontal visual contact with the antenna element 176 of the right side window. In this case, there is therefore a visual connection to three different fixed stations 31, 32, 35. Two antenna elements 176 of the vehicle each have visual contact with the fixed stations. The position for each antenna element 176 can then be determined using two different trilateration calculations. An average can then be calculated between these. The averaging improves the accuracy of the position determination. The position and/or orientation of the vehicle 10 is then determined from the individual positions of the antenna elements 176 on the vehicle 10.

• • Eerfindungsgemäße indirecte Schätzung der Fahrzeugposition und/oder -orientierung aus den vorher mittels Trilateration berechneten und ggfs. gemittelten fahrzeugseitigen Antennenelementpositionen auf Basis der Laufzeitmessungen zu je drei Einzelantennenelementen 31A, 31B, 31C eines einzigen Antennen-Arrays.
• • Direkte Schätzung der Fahrzeugposition und/oder -orientierung mittels Trilateration auf Basis der reflektierten Pulslaufzeiten je eines ausgewählten Antennenelementes 31E aus drei unterschiedlichen im Raum verteilten Antennen-Arrays.

In summary, there are two options for determining the vehicle position and/or orientation:

• • Indirect estimation of the vehicle position and/or orientation according to the invention from the vehicle-side antenna element positions previously calculated by means of trilateration and, if necessary, averaged on the basis of the runtime measurements for three individual antenna elements 31A, 31B, 31C of a single antenna array.
• • Direct estimation of the vehicle position and/or orientation by means of trilateration based on the reflected pulse transit times of a selected antenna element 31E from three different antenna arrays distributed in space.

By carrying out the two above-mentioned methods and averaging the results, it can be ensured that a high level of estimation accuracy is achieved for all vehicle positions and/or orientations. A further increase in accuracy can be achieved by weighting the results from the above-mentioned methods. The weighting factors can result, for example, from a plausibility check in the form of a comparison of the determined vehicle-side antenna positions (e.g. right/left side window) and/or from taking into account the angle of incidence of reflected pulses from the stationary antenna arrays.

It should be understood that the proposed method and associated devices may be implemented in various forms of hardware, software, firmware, special purpose processors, or a combination thereof. Special purpose processors may include application specific integrated circuits (ASICs), Reduced Instruction Set Computers (RISCs), and/or Field Programmable Gate Arrays (FPGAs). Preferably, the proposed method and the Device is implemented as a combination of hardware and software. The software is preferably installed as an application program on a program storage device. Typically, it is a computer platform-based machine that includes hardware such as one or more central processing units (CPU), random access memory (RAM), and one or more input/output (I/O) interfaces. An operating system is also typically installed on the computer platform. The various processes and functions described herein may be part of the application program, or part of what is executed via the operating system.

The disclosure is not limited to the embodiments described herein. There is room for various adaptations and modifications that one skilled in the art would consider to be part of the disclosure based on his or her technical knowledge.

list of reference symbols

10

vehicle

30 - 35

fixed station

31A - 31E

antenna element 5G antenna

40

Evolved Packet Core EPC

50

server

100

block diagram of vehicle electronics

102

High Speed CAN bus

105

camera

104

CAN bus

110

on-board unit

120

navigation system

140

Gateway

151

engine control unit

152

ESP control unit

153

transmission control unit

161

Sensor 1

162

Sensor 2

163

Sensor 3

170

front-end

172

coordination unit

176

vehicle antenna element

Claims (12)

Method for the highly accurate determination of the position and/or orientation of a vehicle (10) to be located, which is designed for communication in a wireless communication network, wherein broadband pulses of short duration are transmitted from the vehicle (10) to surrounding fixed stations (31 - 35), which are answered by the surrounding fixed stations (31 - 35) in an immediate return of a response pulse when received, wherein a measurement of the transit time of the emitted pulse until the arrival of the return pulse from at least one of the surrounding fixed stations (31 - 35) is carried out in the vehicle (10), wherein a respective transmission of a pulse takes place one after the other by a number of antenna elements (176) mounted at different positions of the vehicle (10) with a respective transceiver, wherein for each mounted antenna element (176) a transceiver (170) is located in the vicinity of a position of the antenna element (176) and a communication module (110) with the Transceivers (170) of the antenna elements (176) mounted at the various positions, wherein the communication module (110) is designed to request the various transceivers (170) one after the other to transmit the broadband pulse of short duration or to assign them respective planned times for the successive transmission of the broadband pulses, and the time until the respective response pulse arrives at the individual antenna elements (176) is measured by means of the respective transreceiver (170), wherein the determination of the positions of the antenna elements (176) of the vehicle (10) to be located is carried out based on at least one intersection calculation with the resulting at least three travel times and the known positions of the antennas of the fixed stations (31 - 35) and the position and/or orientation of the vehicle (10) is determined from the determined antenna element positions (176) on the vehicle (10), wherein the antennas each fixed station (31 - 35) is designed in the form of antenna arrays (310) consisting of a number of antenna elements (31A, 31B, 31C, 31E), wherein a single antenna element (31E) is used for the return signal in order to emit the response pulse, wherein three different transit time measurements are carried out one after the other with three different individual antenna elements (31A, 31B, 31C) of the antenna array (310), wherein the individual antenna elements (31A, 31B, 31C) are selected such that they are as far apart from one another as possible. procedure according to claim 1 , wherein the position of the vehicle-side antenna element (176) is calculated by trilateration calculation based on the transit time measurements to the three antenna elements (31A, 31B, 31C) of the antenna array (310) of the base station (31). procedure according to claim 1 , wherein when the response pulses from two or more different surrounding fixed stations (31 - 35) arrive at an antenna element (176) of the vehicle (10), an averaging of the position determinations of the antenna element (176) of the vehicle (10) to be located is carried out. procedure according to claim 1 or 2 , wherein the transit time measurements by the various antenna elements (176) of the vehicle (10) for the pulse sent back from a fixed station (31 - 35) are subjected to a plausibility check, wherein a transit time which was rejected as erroneous during the plausibility check is not used for the intersection point calculation. Method according to one of the preceding claims, wherein the plausibility check is based on a comparison of the measured propagation times taking into account the local proximity of the antenna elements (176) attached to the vehicle (10), and those propagation times are rejected as erroneous whose propagation time does not correlate with the local proximity of the antenna elements (176). procedure according to claim 1 or 2 , wherein a trilateration calculation or multilateration calculation is carried out as the intersection calculation on the basis of the transit time measurements of an antenna element (176) attached to the vehicle (10) for the response pulses sent back from three or more different fixed stations (31 - 35). Device for determining the position and/or orientation of a vehicle (10) to be located for carrying out a method according to one of the Claims 1 until 6 , with a communication module (110) for communication in a wireless communication network with surrounding fixed stations (31 - 35), characterized by a number of antenna elements (176) attached to the vehicle (10) at different positions, each with a transceiver (170) per attached antenna element (176), which is located near the position of the antenna element, wherein the transceiver (170) is designed to generate a broadband pulse of short duration to the surrounding fixed stations (31 - 35) and to receive a response pulse transmitted by the surrounding fixed stations (31 - 35) by direct return, wherein the respective transceiver (170) is designed to measure the transit time of the emitted pulse until the response pulse arrives from one of the surrounding fixed stations (31 - 35), wherein the transmission of the pulse takes place by the number of antenna elements (176) one after the other and the The propagation time from and to the individual antenna elements (176) on the vehicle (10) is measured separately. device according to claim 7 , wherein the communication module (110) is connected to the transceivers (170) of the antenna elements (176) mounted at the various positions and the communication module (110) is designed to request the various transceivers (170) one after the other to transmit the broadband pulse of short duration or to assign them respective scheduled times for a sequential transmission of the broadband pulses. device according to claim 7 or 8 , wherein the communication module (110) is also designed for communication in a mobile radio network and is set up to send an announcement message for the position and/or orientation determination measurement phase to the surrounding fixed stations (31 - 35), with which the arrival of the broadband pulse is announced and the fixed stations (31 - 35) are requested to respond to the incoming pulse by immediately returning the response pulse. device according to claim 9 , wherein the fixed stations (31 - 35) are requested with the announcement message to send their identification to the vehicle (10) in a further pulse or a further pulse sequence or in a logical channel of the wireless communication network following the transmission of the response pulse. Device according to one of the Claims 7 until 10 , wherein the device is arranged in a vehicle (10) and is equipped with at least one 5G single-element antenna (176) on the front, rear and side windows of the vehicle (10), each single-element antenna (176) being connected to a transmitting and receiving unit as a transceiver (170) in the vicinity of the antenna, the various transceivers being networked with one another and with an on-board unit (110) of the vehicle (10). Base station for a mobile radio communication system with an antenna array (310), with a transmitting and receiving unit (320) in a building for carrying out a method according to one of the Claims 1 until 6 with a device in a vehicle according to one of the Claims 7 until 11 , characterized in that the transmitting and receiving unit (320) is designed to announce to receive a notification message for the position and/or orientation determination measurement phase of a vehicle (10) to be located and, in response to receipt of the notification message, to switch to an operating mode in which the arrival of a broadband pulse of short duration is waited for and, upon receipt of the pulse, to immediately send back a response pulse, wherein the transmitting and receiving unit (320) is designed to receive another notification message with which the base station (31 - 35) is placed in a different operating mode in which it determines three antenna elements (31A, 31B, 31C) of the antenna array (310), which each send a response pulse back to the vehicle (10) upon arrival of the broadband pulse for separate transit time measurements.

Images