EP2317603A1 - Multi-standard antenna module - Google Patents

Abstract

The module has a multi-antenna arrangement provided with a global positioning system antenna (24), a cellular antenna (26) and two vehicle-to-vehicle (V2V)- and/or infrastructure-to-vehicle (I2V) antennas (28, 30). A signal processing unit (34) is attached to one of the antennas in the arrangement. The V2V and/or I2V antennas are spatially arranged at a distance from each other for utilization of antenna diversity. The arrangement is designed for multiple input multiple output (MIMO) communication connections.

Description

The invention relates to a multi-standard antenna module for traffic telematics systems.

Traffic telematics is the use of telematics in transport. It covers everything that has to do with vehicles, their occupants and the sending, receiving, processing and presentation of data in a motor vehicle. Furthermore, transport telematics supports the coordination of road traffic.

The currently known traffic telematic systems include navigation and cellular services. These services can be used to increase traffic safety. There are already different telematics specifications. For example, there is already the "OnStar" system for North America and the "eCall" system for Europe. Common to both services is that in the event of an emergency they can send a message via a cellular network containing the GPS position. The GPS position means the position determined by means of a global positioning system GPS (Global Positioning System).

Antenna modules for traffic telematics systems therefore combine navigation and features of a cellular network (typically cellular 2G and 3G networks), including antennas for both of these services.

Typically, the cellular and navigation services include multiple standards. Accordingly, the antenna modules used for this purpose are referred to as multi-standard antenna modules. For cellular services, European frequency allocation requires at the same time system functionality in the bands 810-960 MHz, 1710-1880 MHz (both called 2G frequencies) and 1920-2170 MHz (so-called 3G frequencies). Usually, the various antennas are housed in a housing which is applied in the rear of the vehicle center of the vehicle roof. Fig. 1 shows a schematic plan view of such a conventional antenna module, here roof antenna module 10 for traffic telematics systems with a GPS antenna 12 and a cellular antenna 14. In this case, these two antennas 12, 14 housed in a common housing 16. The antenna module 10 is aligned in the direction of travel x of the vehicle in question. Fig. 2 shows a schematic plan view of a provided with such a roof antenna module 10 motor vehicle 18th

It is expected that more sophisticated multi-standard antenna modules will be required for future vehicle safety applications with more sophisticated traffic telematics functionality, especially from 2011 onwards. Thus, it would be particularly advantageous if the multistandard antenna modules were additionally provided with antenna elements for V2V (vehicle to vehicle) communication links, that is, vehicle-to-vehicle communication links.

Fig. 3 shows a schematic plan view of an antenna module 10, in particular rooftop antenna module, for traffic telematics systems, in addition to a GPS antenna 12 and a cellular antenna 14 already includes a V2V antenna 20, which may be provided in particular for communication links at 5.9 GHz.

According to the European Commission's Frequency Directive 2008/671 / EC, V2V communication links are currently defined as connections within a bandwidth of 30 MHz, centered around the 5.89 GHz frequency. V2V communication is in line with the European Union's "i2010" initiative on "smart vehicles" for increased traffic efficiency and reducing the number of traffic accidents.

The invention has for its object to provide a compact multistandard antenna module as possible, which is as variable as possible and in particular suitable for more complex future traffic telematics systems.

According to the invention, this object is achieved by a multi-standard antenna module for traffic telematics systems having at least one GPS antenna, at least one cellular antenna and at least two V2V or at least two I2V antennas comprising multi-antenna arrangement and preferably a signal processing unit associated with the antennas, wherein the V2V- or I2V antennas of the multi-antenna arrangement for the use of an antenna diversity spatially correspondingly spaced from each other.

Where appropriate, I2V (infrastructure to vehicle) antennas are provided for infrastructure-to-vehicle communication links.

Preferably, the multi-antenna arrangement comprises only two V2V or I2V antennas.

By using multiple antennas per transmitter or receiver, a so-called antenna diversity can be used to reduce interference effects in radio transmission.

According to a preferred embodiment of the multistandard antenna module according to the invention, at least one of the V2V or I2V antennas of the multi-antenna arrangement has a double-resonance radiation behavior. In this case, the double resonance can be given in particular in the range of the two frequencies 2.45 GHz and 5.9 GHz.

It is also of particular advantage if the multi-antenna arrangement comprising the V2V or I2V antennas is designed for MIMO (multiple input multiple output) communication connections, wherein preferably a use of the MIMO technology can also be provided in the 5 GHz range. With the multi-size system MIMO, that is, the use of multiple transmit and receive antennas for wireless communication special coding methods can be used in particular, not only the temporal, but also the spatial dimension for information transmission use (Space-Time Coding), which among other things, the bit error rate can be reduced and the data rate of each wireless connection can be significantly increased.

The signal processing unit assigned to the antennas is advantageously designed to use a particularly adaptive antenna diversity. The antenna diversity can therefore be adapted to the respective circumstances.

It is also particularly advantageous if the signal processing unit assigned to the antennas is designed for a particularly adaptive beam shaping. In this case, for example, by the control of different Antenna elements or antennas, the respective beam shape are generated.

The V2V or I2V antennas of the multi-antenna arrangement preferably cover the earth region.

Preferably, each of the V2V or I2V antennas comprises an individual high-frequency line.

According to a further advantageous embodiment of the multistandard antenna module according to the invention, the multi-antenna arrangement comprising the V2V or I2V antennas is designed both for infotainment and for security-relevant communication connections. Infotainment is the link between conveying information and entertainment. For this purpose, for example, a so-called multi-media interface, called "MMI" may be provided. In addition to the radio program, an MMI system can also provide complex tasks such as a quick reproduction of the current traffic situation and the display of the map material of the navigation system. For example, the operation of the phone, the selection of a particular television program or the setting of comfort features of the vehicle can round off the applications.

The antennas can be housed in particular in a common, preferably mountable on a vehicle roof housing.

In principle, it is also conceivable that at least partially the signal processing unit is accommodated in the housing. The signal processing unit However, at least partially realized in the control unit of the vehicle in question.

The antennas can each be provided as a transmitting and / or receiving antenna.

A preferred practical embodiment of the multistandard antenna module according to the invention is characterized in that the signal processing unit comprises an antenna processor which is connected to the multi-antenna arrangement comprising the V2V or I2V antennas in order to control the input or output signals of the V2V or I2V Antennas in particular to use a preferably adaptive antenna diversity to combine in a defined manner.

It is also particularly advantageous if the signal processing unit comprises a traffic telematics processor which is connected both to the V2V or I2V antennas of the multi-antenna arrangement and to the GPS antenna and the cellular antenna in order to supply their input or output signals to the traffic telematics service combine.

The traffic telematics processor is preferably connected via the antenna processor to the multi-antenna arrangement comprising the V2V or I2V antennas.

V2V communication systems are gaining increasing attention because they can reduce the occurrence of congestion and the number of traffic accidents by sharing information among multiple vehicles through a mobile vehicle network. In particular, the implementation of future V2V systems is facilitated with the multistandard antenna module according to the invention. By combining the information of the GPS navigation with the sensor information obtained via the V2V or I2V communication connections (for example, road and traffic conditions), both the traffic safety and the transport efficiency can be significantly increased. For example, the collected information may be returned to a larger cellular network that may be connected to traffic planners, insurance companies, and other third parties interested in real-time traffic information. In addition, V2V communication links in active safety systems make a significant contribution to reducing the number of traffic accidents.

Determining the performance of new systems for V2V communication links, such as the IEEE 802.11p advanced system in particular, requires a thorough understanding of the underlying transmission channels between moving vehicles. However, the time and frequency selective fading or fading characteristic of such V2V channels now differs significantly from that of the well-studied cellular, that is, base station-to-vehicle channels. The results of measurements carried out show that the assumptions made in connection with the fading or fading in the conventional so-called WSSUS channel model (Wide-Sense Stationary Uncorrelated Scattering) in particular on V2V channels at the frequency 5.9 GHz do not apply because the channel fluctuations very occur quickly. Consequently, the V2V channel must be considered as a non-static fading or fading channel.

Due to the presence of a large number of vehicles in heavily loaded V2V systems and the nature of rapidly changing channel parameters, Multi-antenna technologies are becoming increasingly important. Thus, they provide the appropriate means for flexible network coverage, interference mitigation, and diversity functionality for security-critical communications applications.

By means of such methods and in particular the multistandard antenna module according to the invention, it is now possible to reduce the interference level in heavily loaded communication systems, in particular by adaptive diversity and beamforming techniques and thus to increase the signal-to-noise ratio of the relevant communication system, thereby improving its operational reliability. In addition, with the adaptive diversity techniques which can now be used according to the invention, the reliability of the wireless communication connection can be increased by a suitable signal combination between individual antenna elements or antennas. For example, all types of multi-antenna techniques, including adaptive diversity and beamforming functionality, may be combined as part of a MIMO (multiple-input multiple-output) communication system.

Multi-antenna techniques at the transmitter or at the receiver, i.e., for example, MIMO communication links, can be advantageously used for diversity operations to reduce fading effects and counter multipath propagation of the electromagnetic field inherent in V2V or vehicle-to-vehicle transmissions. Communication connections occurs. In particular in the context of safety-critical applications involving human life, diversity operations or measures are meant for V2V communication connections are an essential aspect of the V2V communication architecture.

Physical or spatial distances of the order of magnitude of one wavelength at the V2V operating frequency, for example around 5.9 GHz, are essential prerequisites in order to obtain a sufficiently large diversity gain in the stochastic mean value. With the use of multi-antenna elements for the V2V communication connection, other physical fading phenomena such as polarization or spatial energy distribution can occur.

In addition to V2V communication links for traffic safety in the 5.9 GHz exclusive frequency band in Europe, wireless local area networks or so-called WLAN (wireless local area network) systems, in particular according to the IEEE 802.11 standard, can also bring additional vehicle comfort functions, in particular with regard to infotainment , For example, systems according to the extended IEEE 802.1 ln standard will involve MIMO antenna operations at the transmitter and at the receiver for higher data rates by a spatial multiplexing in the frequency range of 2.45 GHz, namely in the range of 2.412 to 2.484 MHz. In the course of the ongoing standardization of WLAN systems, in particular, the use of MIMO technology in the 5 GHz band is possible. Therefore, it is particularly advantageous if at least one of the V2V or I2V antennas of the multi-antenna arrangement of the multi-standard antenna module has a double-resonance radiation behavior, the double resonance being given in particular in the range of the two frequencies 2.45 GHz and 5.9 GHz can be.

In view of the increasing system complexity resulting from the integration of multiple antennas for V2V services, in practice a compromise has to be made between increased manufacturing and system costs on the one hand and an improvement in performance on the other hand.

Since each of the V2V antennas requires an individual high frequency line provided between the antenna module and a remote transceiver, the maximum number of individual antenna elements must be limited. However, each additional antenna element introduces an additional degree of freedom, which increases the diversity efficiency of the multi-antenna array. Since the relative improvement in performance decreases with each additional antenna element, as shown for example by the so-called MRC (maximum ratio combining), a variant of the spatial diversity, the number of antennas of the multi-antenna array, in particular for the V2V communication link, e.g. in the 5.9 GHz band can reasonably be limited to two.

Fig. 1

eine schematische Draufsicht eines herkömmlichen Dach-Antennenmoduls für Verkehrstelematiksysteme,

Fig. 2

eine schematische Draufsicht eines mit einem Dach- Antennenmodul versehenen Kraftfahrzeugs,

Fig. 3

eine schematische Draufsicht eines Antennenmoduls, insbesondere Dach-Antennenmoduls, für Verkehrste- lematiksysteme, das außer einer GPS-Antenne und ei- ner Zellularantenne auch eine V2V-Antenne umfasst,

Fig. 4

eine schematische Draufsicht einer beispielhaften Aus- führungsform eines erfindungsgemäßen Multistan- dard-Antennenmoduls für Verkehrstelematiksysteme,

Fig. 5

ein Blockdiagramm zur Veranschaulichung einer bei- spielhaften Nutzung der Antennen-Diversität für V2V- Kommunikationsverbindungen,

Fig. 6

ein Blockdiagramm zur Veranschaulichung einer bei- spielhaften Nutzung des Raummultiplexverfahrens für V2V-Kommunikationsverbindungen,

Fig. 7

eine schematische Darstellung der verschiedenen An- tennen einer beispielhaften Ausführungsform eines er- findungsgemäßen Multistandard-Antennenmoduls mit einer den Antennen zugeordneten Signalverarbei- tungseinheit und

Fig. 8

eine beispielhafte Darstellung des Diversitäts-Gewinns für das MRC in Abhängigkeit von der Anzahl unab- hängiger Antennen der Mehrantennenanordnung.

Further features and advantages of the invention will become apparent from the following, described with reference to the drawings embodiments. In the drawing show:

Fig. 1

a schematic plan view of a conventional roof antenna module for traffic telematics systems,

Fig. 2

a schematic plan view of a provided with a roof antenna module motor vehicle,

Fig. 3

1 is a schematic plan view of an antenna module, in particular a roof antenna module, for traffic control systems which, in addition to a GPS antenna and a cellular antenna, also comprises a V2V antenna,

Fig. 4

FIG. 2 shows a schematic plan view of an exemplary embodiment of a multistandard antenna module according to the invention for traffic telematics systems, FIG.

Fig. 5

a block diagram illustrating an exemplary use of the antenna diversity for V2V communication links,

Fig. 6

FIG. 2 is a block diagram illustrating an exemplary use of space division multiplexing for V2V communication links; FIG.

Fig. 7

a schematic representation of the various antennas of an exemplary embodiment of a multi-standard antenna module according to the invention with a signal processing unit associated with the antennas and

Fig. 8

an exemplary representation of the diversity gain for the MRC as a function of the number of independent antennas of the multi-antenna array.

Fig. 4 shows a schematic plan view of an exemplary embodiment of a multi-standard antenna module 22 according to the invention for traffic telematics systems.

As based on the Fig. 4 1, the multi-standard antenna module 22 comprises a GPS antenna 24, a cellular antenna 26 and two V2V antennas 28, 30. Alternatively or additionally, two I2V antennas may also be provided.

The V2V antennas 28, 30 forming a multi-antenna arrangement are spatially correspondingly spaced apart from each other for use of antenna diversity.

The antennas 24 to 30 can be housed in a common, in particular mounted on a vehicle roof housing 32.

In addition, the multi-standard antenna module 22 may be a signal processing unit 34 assigned to the antennas 24 to 30 (cf. Fig. 7 ). In this case, this signal processing unit 34 may be provided outside of the housing 32 or at least partially also within this housing. However, it can be at least partially realized in the control unit of the vehicle in question.

The housing 32 containing the GPS antenna 24, the cellular antenna 26 and the two V2V antennas 28, 30, preferably mounted on the roof of a vehicle, may be aligned with the direction of travel x of the relevant vehicle.

The V2V or I2V antennas 28, 30 of the multi-antenna arrangement formed by these antennas can have a double-resonance radiation behavior, wherein the double resonance can be given for example in the range of the two frequencies 2.45 GHz and 5.9 GHz.

The multi-antenna arrangement comprising the V2V or I2V antennas 28, 30 can be designed in particular for MIMO communication connections.

The antennas 24 to 30 associated signal processing unit 34 (see. Fig. 7 ) can be designed to use a particular adaptive antenna diversity, in particular, the two V2V or I2V antennas 28, 30 of the multi-antenna arrangement are used for the use of such antenna diversity.

The antennas 24 to 30 associated signal processing unit 34 (see. Fig. 7 ) may alternatively or additionally be designed in particular for a preferably adaptive beam shaping.

The multi-antenna arrangement or the associated V2V or I2V antennas 28, 30 cover in particular the earth region.

The multi-antenna arrangement comprising the V2V or I2V antennas 28, 30 is expediently provided with only one feed connection.

Alternatively or additionally, the multi-antenna arrangement comprising the V2V or I2V antennas 28, 30 can be designed both for infotainment and for security-relevant communication connections.

The antennas 24 to 30 can each be provided as a transmitting and / or receiving antenna.

Fig. 5 shows a block diagram illustrating an exemplary use of the aforementioned antenna diversity for V2V communication links. An example of a simple diversity signal processing technique for RX (receive) diversity with two antennas or antenna elements 28, 30 for V2V communication links is shown.

Like the one in the upper left part of the Fig. 5 The amplitude distribution shown in a typical multipath scenario, the spatial distance between the individual antennas 28, 30 plays an essential role in the efficiency of V2V diversity operations.

The physical or spatial distances of the order of magnitude of the wavelength at the V2V operating frequency of 5.9 GHz are important prerequisites for achieving a sufficiently large diversity gain in the stochastic mean.

Again Fig. 5 Moreover, the output signal ri (t) of the antenna 28 is supplied to a receiver 36 and the output signal R _N (t) of the antenna 30 to a receiver 38. Following the receivers 36, 38, a so-called diversity combination can take place.

Fig. 6 shows a block diagram illustrating an exemplary use of the space division method for V2V communication links.

In the illustrated MIMO configuration, M antennas 28, 30 are provided at the transmitter and N antennas 28, 30 at the receiver. It can be a signal processing as in the case of the Fig. 5 reproduced use of the antenna diversity, for example, in an antenna processor 38 (see. Fig. 7 ) which combines the output signals on the TX (transmit) side and the incoming signals on the RX (receive) side. For the in the Fig. 6 reproduced MIMO signal processing, the antenna processor 38 (see also Fig. 7 ) on the RX side provide filtering and STD decoding of the signal combination.

Fig. 7 1 shows a schematic representation of the various antennas 24 to 30 of an exemplary embodiment of the multistandard antenna module according to the invention with a signal processing unit 34 assigned to these antennas 24 to 30.

The signal processing unit 34 may comprise an antenna processor 38 which is connected to the multi-antenna arrangement comprising the V2V antennas 28, 30 in order to use the input and output signals of the V2V antennas 28, 30 in particular for the use of a preferably adaptive antenna diversity in a defined manner to combine.

The signal processing unit 34 may further include a traffic telematics processor 40 coupled to both the V2V antennas 28, 30 of the multi-antenna array and the GPS antenna 24 and the cellular antenna 26 for combining their input and output signals to the traffic telematics service.

Again Fig. 7 can be seen, the traffic telematics processor 40 may be connected via the antenna processor 38 with the V2V antennas 28, 30 comprising multi-antenna arrangement.

In principle, more than two V2V antennas can be provided. Instead of or in addition to the V2V antennas, I2V antennas can also be used.

The antenna processor 38 may in particular be a so-called smart antenna processor.

The antenna processor 38 can therefore be provided in particular for combining the signals of the at least two V2V or I2V antennas 28, 30, while the traffic telematics processor 40 can be provided in particular for combining the GPS, cellular and V2V or I2V services in order to achieve higher traffic efficiency and reduce the number of traffic accidents. The two functionalities of the signal processing unit 24 can be combined and accommodated in a head unit of the vehicle.

Fig. 8 shows an exemplary representation of the diversity gain for the MRC (maximum ratio combining) as a function of the number of independent antennas of the multi-antenna array. Here, the theoretically achievable diversity gain for the MRC is represented with a 1% and 10% probability of failure for a different number of independent diversity branches: in the transition from one to two independent reception branches, the maximum of the relative diversity gain results.

LIST OF REFERENCE NUMBERS

10

antenna module

12

GPS antenna

14

cellular antenna

16

casing

18

vehicle

20

V2V antenna

22

Multi-standard antenna module

24

GPS antenna

26

cellular antenna

28

V2V or I2V antenna

30

V2V or I2V antenna

32

casing

34

Signal processing unit

36

receiver

38

antenna processor

40

Traffic telematics processor

x

direction of travel

Claims (15)

A multi-standard antenna module (22) for traffic telematics systems comprising at least one GPS antenna (24), at least one cellular antenna (26) and at least two multi-antenna devices comprising at least two V2V or at least two I2V antennas (28, 30) and preferably one of the antennas (24 -30) associated signal processing unit, wherein the V2V or I2V antennas (28, 30) of the multi-antenna arrangement for the use of an antenna diversity spatially correspondingly spaced from each other. Multi-standard antenna module according to claim 1,
characterized,
that at least one of the V2V or I2V antennas (28, 30) of the multi-antenna arrangement has a double resonance-radiation behavior. Multi-standard antenna module according to claim 2,
characterized,
that the double resonance is given in the range of the two frequencies 2.45 GHz and 5.9 GHz. Multi-standard antenna module according to one of the preceding claims,
characterized,
that the V2V or I2V antennas (28, 30) comprising multi-antenna array for MIMO communication links designed is, wherein preferably a use of MIMO technology is also provided in the 5 GHz band. Multi-standard antenna module according to one of the preceding claims,
characterized,
in that the signal processing unit (34) assigned to the antennas (24-30) is designed to use a particularly adaptive antenna diversity. Multi-standard antenna module according to one of the preceding claims,
characterized,
in that the signal processing unit (34) associated with the antennas (24-30) is designed for particularly adaptive beamforming. Multi-standard antenna module according to one of the preceding claims,
characterized,
that the V2V or I2V antennas (28, 30) of the multi-antenna arrangement covering the earthly realm. Multi-standard antenna module according to one of the preceding claims,
characterized,
that each of the V2V or I2V antennas (28, 30) includes an individual high-frequency line. Multi-standard antenna module according to one of the preceding claims,
characterized,
that the V2V or I2V antennas (28, 30) comprising multi-antenna arrangement is designed for both infotainment and for safety-related communications links. Multi-standard antenna module according to one of the preceding claims,
characterized,
in that the antennas (24-30) are accommodated in a common housing (32) which can be mounted in particular on a vehicle roof. Multi-standard antenna module according to claim 10,
characterized,
that at least partially the signal processing unit (34) is housed in the housing (32). Multi-standard antenna module according to one of the preceding claims,
characterized,
that the antennas (24-30) are each provided as a transmitting and / or receiving antenna. Multi-standard antenna module according to one of the preceding claims,
characterized,
in that the signal processing unit (34) comprises an antenna processor (38) comprising the V2V or I2V antennas (28, 30) Multi-antenna arrangement is connected to the input or output signals of the V2V or I2V antennas (28, 30) in particular to use a preferably adaptive antenna diversity to combine in a defined manner. Multi-standard antenna module according to one of the preceding claims,
characterized,
in that the signal processing unit (34) comprises a traffic telematics processor (40) which is connected both to the V2V or I2V antennas (28, 30) of the multi-antenna arrangement and to the GPS antenna (24) and the cellular antenna (26), to combine their input and output signals for the traffic telematics service. Multi-standard antenna module according to one of the preceding claims,
characterized,
in that the traffic telematics processor (40) is connected via the antenna processor (38) to the multi-antenna arrangement comprising the V2V or I2V antennas (28, 30).

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