Communication device for radio transmission of communication data and motor vehicle with the communication device

Abstract

Communication device (11) for radio transmission of communication data (12), with - an antenna (16) for transmitting and / or receiving electromagnetic radio waves (17, 18) representing the communication data (12), and - a front end unit (20) electrically connected to the antenna (16) for amplifying and / or mixing an analog electrical antenna signal (19) containing the communication data (12), and - a processor unit (26) which is configured to generate and / or receive the communication data (12) and / or to exchange it with a digital communication network, wherein - the processor unit (26) is connected to the front end unit (20) via a signal cable (27), characterized in that at the front end unit side of the signal cable (27) a digital transmission circuit (29) for MIPI A-Phy signal transmission of sensor data is provided and an analog signal terminal (30) of the digital transmission circuit (29) is connected to the front end unit (20) and a digital signal terminal (31) of the digital transmission circuit (29) is connected to the signal cable (27) and the front end unit (20) and the processor unit (26) are coupled to each other by means of a digital signal transmission based on the digital transmission circuit (29) and the processor unit (26) is configured to mix the digital signal (28) by means of a digital mixer (32) for sending out of a baseband and / or for receiving into the baseband.

Description

[0001] The invention relates to a communication device for the wireless transmission of communication data. The wireless transmission is effected by means of an antenna for sending and / or receiving electromagnetic waves. The wireless transmission can originate from the communication device, in which case the radio wave is sent, or be directed to the communication device, in which case the radio wave is received. The invention also includes a motor vehicle equipped with the communication device according to the invention.

[0002] An antenna converts electromagnetic radio waves into an analog electrical antenna signal (receiving) and / or the analog electrical antenna signal into an electromagnetic radio wave (transmitting). Transmitting communication data at high data rates over a wireless communication link requires a high bandwidth, i.e., high frequencies for the radio waves. For this reason, increasingly higher frequency ranges are being developed for radio transmission or wireless communication and adopted in radio transmission standards. For example, the upcoming 5G mobile communications standard is discussing transmission using radio waves in the frequency range around 26 GHz.

[0003] High radio frequencies above 2 GHz have the disadvantage that a typical analog cabling connection between the actual antenna for transmitting and / or receiving electromagnetic radio waves on the one hand, and an electrical circuit for processing the antenna signal on the other, results in relatively high attenuation, which can impair the functionality of the radio transmission. To avoid such high line attenuation, bidirectional amplification can be provided in a so-called RF front end (Radio Frequency Front End), i.e., a front-end unit (antenna driver circuit) for electrically processing the antenna signal, located close to the actual antenna. Additionally or alternatively, bidirectional amplification can also be provided at the end of a signal cable furthest from the antenna to condition the cable signal there.However, a compensator used for this purpose has the disadvantage that its control system and / or the requirements for approval are complex. Furthermore, such a compensator requires a relatively high amount of electrical power and is expensive. As an alternative to compensation, the entire electrical circuitry can be located close to the antenna to achieve the shortest possible cable lengths. However, when installing an antenna in a vehicle, for example in the roof, there is usually insufficient space to accommodate the numerous required electronic components, especially the processor for digital signal processing of the communication data, so close to the antenna.

[0004] A compact arrangement of receiver electronics for operating multiple antennas is known from DE 10 2015 016 334 A1. This patent describes a solution whereby an antenna can be directly connected to a CPU via a short cable or a trace on a circuit board. No special measures for analog signal transmission via a coaxial cable are described, as they are unnecessary in this case. However, the CPU must be positioned close to the antenna.

[0005] From DE 10 2016 214 855 A1, it is known that a processor unit can be connected to an antenna to control a radio transmission by means of digital signal processing. All antennas are connected to the processor unit via analog signal cables, and amplifier modules on the processor unit side can perform an analog-to-digital conversion to digitally acquire the transmitted antenna signals. The amplifier modules thus have the described functionality of a compensator at the end of a signal cable furthest from the antenna.

[0006] From US 2010 / 0 284 384 A1 it is known that radio transmission can be based on a protocol stack for WLAN (Wireless Local Area Network).

[0007] US patent 2019 / 0149205A1 discloses that multiple antennas can be installed at different locations in a motor vehicle, and that the signals from these antennas can be combined in a central processing unit. The circuitry at the antennas is to be minimized, for which purpose the antennas only have a front-end unit and an analog-to-digital converter to transmit a digitized signal to the central processing unit.

[0008] In DE 11 2017 000 792 T5 a mixer is described which enables signal mixing from a transmit frequency band directly into the baseband at a frequency of 2 gigahertz.

[0009] German patent DE 10 2010 053 968 B4 describes how antennas for Bluetooth and Wi-Fi can be interconnected with a processor system via an RF processing circuit and an analog-to-digital converter. Downconversion to the baseband occurs analogously before the analog-to-digital converter.

[0010] From DE 11 2017 007 368 T5 it is known to provide an arrangement of antennas, front end unit, RF circuit arrangement and processor device for vehicle-to-vehicle communication in order to send and receive signals.

[0011] US patent 2019 / 0077434A1 discloses a Wi-Fi-based transmit / receive system for monitoring a railroad crossing. The processor used for this purpose operates exclusively in the baseband. The conversion from the analog signal path to the digital signal path takes place in a PHY unit, which may be integrated into the processor.

[0012] The invention is based on the objective of being able to arrange an antenna on the one hand and a processor device for digital processing of communication data on the other hand in a spatially separate manner.

[0013] The problem is solved by the subject matter of the independent claims. Advantageous embodiments of the invention are described by the dependent claims, the following description, and the figure.

[0014] The invention provides a communication device for the wireless transmission of communication data. Such communication data can, for example, be part of an internet connection (for internet browsing) and / or a telecommunications connection (video and / or voice telephony) and / or device communication, for example, between a motor vehicle with autonomous driving functions and an external device (for example, another autonomous motor vehicle and / or an infrastructure component of a transportation network). The communication device has an antenna for transmitting and / or receiving electromagnetic radio waves. These radio waves represent or contain the aforementioned communication data. In other words, the communication data is described by a temporal profile of the radio waves.The communication device also includes a front-end unit electrically connected to the antenna for amplifying and / or mixing an analog electrical antenna signal. Another term for such a front-end unit is RF front-end or antenna driver circuit. The analog electrical antenna signal serves to transmit the aforementioned communication data; that is, it contains the communication data. In other words, the temporal profile of the antenna signal also describes the communication data. When receiving the radio waves, the analog electrical signal is impressed into the antenna by the radio waves. When transmitting the communication data, the electrical analog antenna signal is provided by the front-end unit, and thus the electromagnetic radio waves are generated by the antenna.The communication device further includes a processor configured to generate (in the case of transmission) and / or receive (in the case of reception) communication data and / or exchange communication data with a digital communication network (i.e., to mediate communication data between the front-end unit and the communication network). The processor can therefore also forward communication data, for example, from a communication network, and / or receive it from the front-end unit and feed it into or forward it to the communication network. For this purpose, the processor can be configured, for example, as a router and / or a gateway. The communication network can be, for example, a data bus (e.g., CAN - Controller Area Network) and / or an Ethernet network.

[0015] The invention can be used for both transmission directions (sending and receiving) or for only one of the two transmission directions. At least a portion of the communication data can be sent and / or at least a portion of the communication data can be received. The processor device in question can, for example, be implemented on the basis of at least one microprocessor and / or at least one microcontroller. For the operation of the processor device, program code with program instructions can be stored in a data memory. When executed by the processor device, these instructions cause the generation and / or reception of the communication data.

[0016] In the communication device, the processor unit is connected to the front-end unit via a signal cable. In the prior art, this signal cable experiences undesirably high attenuation as described above, which may necessitate compensation through amplification and / or require the signal cable to be very short, particularly shorter than 1 m.

[0017] To avoid this necessity, the invention provides for a digital transmission circuit. This digital transmission circuit is preferably designed for MIPI A-Phy signal transmission (MIPI - Mobile Industry Processor Interface). However, another standard may also be used. MIPI A-Phy signal transmission is typically intended for transmitting sensor data, such as sensor data from a camera (see, for example, the website https: / / www.mipi.org / specifications / a-phy). The digital transmission circuit provided in the front-end unit is located at the front-end end of the signal cable and is connected to the front-end unit via an analog signal connection. In other words, an input and / or an output of a digital-to-analog converter can be connected to the front-end unit.A digital signal connection is connected to the signal cable. In other words, the output of the analog-to-digital converter and / or the input of the digital-to-analog converter can be connected to the signal cable. Thus, the digital transmission circuit can generate digital data or a digital signal from the antenna signal of the front-end unit and / or generate the analog antenna signal from a digital signal in the signal cable. The front-end unit and the processor unit are configured to exchange this information (transmitted wirelessly) via the signal cable as a digital signal. "Exchange" here means that the transmission can occur from the processor unit to the front-end unit and / or from the front-end unit to the processor unit.

[0018] In other words, the front-end unit and the processor are coupled via a digital signal transmission based on the digital transmission circuit, preferably for MIPI A-Phy signal transmission of sensor data. Thus, the MIPI A-Phy signal transmission is repurposed or given a new use by connecting an antenna to a processor unit via the digital transmission circuit.

[0019] The invention offers the advantage that attenuation in the signal cable has a less pronounced impact on the signal-to-noise ratio of the transmitted communication data, since the communication data is present as a digital signal. Even if the digital signal becomes noisy, the data content, i.e., the communication data, can still be freed from the influence of the noise and / or the communication data can be reconstructed, as digital signal levels can be reconstructed even in a noisy state up to a known signal-to-noise ratio. Furthermore, channel coding can be added to the digital signal for error protection. This channel coding can, for example, be based on a Hamming code.

[0020] In the invention, the processor is configured to mix the digital signal using a digital mixer for transmission from a baseband and / or for reception into the baseband. This enables end-to-end digital signal processing from the digital transmission circuit to an output of the processor, for example, to the aforementioned communication network.

[0021] The invention also includes embodiments that offer additional advantages.

[0022] In one embodiment, the front-end unit for amplifying the antenna signal includes an amplifier circuit for signal amplification. The digital transmission circuitry on the front-end unit is connected to this amplifier circuitry. In other words, the digitization takes place in the same frequency band as the amplifier circuitry. This eliminates the need for a mixer.

[0023] In one embodiment, the front-end unit includes a mixer for frequency mixing. Another term for such a mixer is frequency converter. Using such a mixer, the antenna signal can be down-converted to an intermediate frequency (IF) or an IF band (receive) and / or up-converted from the IF band to a transmit frequency band (transmit). It is specifically assumed that the mixer does not mix into the baseband. A baseband is a frequency band that also contains the DC component (frequency = 0). In contrast, an IF band and / or a transmit frequency band is a frequency band that does not contain the DC component. The digital transmission circuitry is connected to the mixer in the front-end unit. In other words, the digitization is performed in the IF band.This offers the advantage that a lower or smaller sampling rate can be used than in the case of digitization in the transmit / receive frequency band.

[0024] In one embodiment, the digital transmission circuit is configured to perform analog-to-digital conversion of the antenna signal and / or digital-to-analog conversion of the digital signal at a sampling rate greater than 1 GHz. In other words, a crystal oscillator or clock circuit is operated at more than 1 GHz for the conversion. This offers the advantage that the digital signal can be transmitted outside or above the baseband of the radio transmission.

[0025] In one embodiment, the digital transmission circuit is configured to transmit I / Q samples using the digital signal (I / Q - In-Phase and Quadrature). This offers the advantage that phase information of the antenna signal is also transmitted in the digital signal.

[0026] In one embodiment, the signal cable has a length of more than 1 m, in particular more than 2 m. This offers the advantage that the antenna can be installed in a different installation space than the processor unit, along with the front-end unit.

[0027] In one embodiment, the processor is connected to at least one sensor via a separate signal cable. This sensor is configured to transmit a sensor signal to the processor using a digital transmission circuit for MIPI A-Phy signal transmission. In other words, the sensor signal from the sensor is transmitted using MIPI A-Phy signal transmission, as is standard practice for MIPI A-Phy signal transmission. Furthermore, by also transmitting the communication data of the antenna signal as a digital signal using MIPI A-Phy signal transmission, the communication device provides a unified interface for sensor data and communication data (radio communication data).

[0028] In one embodiment, the processor is configured to perform vehicle-to-vehicle communication (C2C communication) and / or vehicle-to-X communication (C2X communication) using radio waves and / or communication data. For this purpose, the processor is configured to operate a protocol stack for a 5G mobile connection and / or a C2X communication connection. Thus, the communication device in a motor vehicle can be used for radio communication with another motor vehicle (vehicle-to-vehicle communication) and / or for radio communication with, for example, an infrastructure component of a traffic network (vehicle-to-X communication).

[0029] Accordingly, the invention also provides a motor vehicle in which an embodiment of the communication device according to the invention is provided. The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0030] The invention also includes combinations of the features of the described embodiments.

[0031] Exemplary embodiments of the invention are described below. The single figure (Fig.) illustrates this: Fig. a schematic representation of an embodiment of the motor vehicle according to the invention.

[0032] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0033] In the figures, identical reference symbols denote functionally equivalent elements.

[0034] The figure shows a motor vehicle 10, which can be, for example, a car, in particular a passenger car or truck. A communication device 11 can be provided in the motor vehicle 10, by means of which communication data 12 can be exchanged between the motor vehicle 10, for example, at least one control unit 13 of the motor vehicle 10, on the one hand, and an external device 14 on the other. The external device 14 can, for example, comprise another motor vehicle and / or an infrastructure component of a traffic network (for example, a traffic light and / or a traffic management system). The transmission of the communication data 12 can take place via a radio link 15. For this purpose, an antenna 16 can be provided in the motor vehicle 10, which can emit radio waves 17 and / or receive radio waves 18.A transmission frequency range of radio waves 17, 18 can be in a range of, for example, 1 GHz to 70 GHz, in particular in a range of 1 GHz to 30 GHz.

[0035] To convert the signal between radio waves 17, 18 on the one hand and an electrical antenna signal 19 on the other, the antenna 16 can, for example, be configured as a patch antenna and / or as an antenna array and / or as a whip antenna, to name just a few antenna types. The electrical antenna signal 19 is then an analog signal with frequencies in the transmission frequency range of the radio waves 17, 18. The antenna 16 can be connected to a front-end unit 20, which can be configured in a manner known per se. The front-end unit 20 can have an amplifier 21 for amplifying the antenna signal 19. For this purpose, at least one receiving amplifier 22 and / or at least one transmitting amplifier 23 can be provided in a manner known per se. A bandpass filter 24 can be provided for setting and / or defining a receiving frequency range and / or a transmitting frequency range.For mixing the antenna signal 19, for example between the transmit frequency range / receive frequency range on the one hand and an intermediate frequency range, a mixer 25 can be provided.

[0036] The communication data 12 can be processed or received by a processor unit 26 for sending and / or receiving. The processor unit 26 can, for example, also include at least one microprocessor and / or at least one microcontroller. The processor unit 26 can, for example, be configured as a router and / or gateway of a data network or communication network of the motor vehicle 10, to which at least one control unit 13 can be connected. To connect the processor unit 26 to the front-end unit 20, a signal cable 27 can be provided, which can have a cable length of more than 1 m. This allows the front-end unit 20 with the antenna 16 to be located, for example, in the roof of the motor vehicle 10, while the processor unit 26 can be located in an area other than the roof, for example, in a trunk or in a center console of the motor vehicle 10.To minimize the influence of signal attenuation on the communication data 12 despite the length of the signal cable 27, the communication device 11 in the motor vehicle 10 can be equipped with a digital transmission over the signal cable, meaning the communication data 12 is transmitted as a digital signal 28 in the signal cable 27. For this purpose, the signal cable 27 can be coupled, connected, or linked to the front-end unit 20 at its antenna end via a digital transmission circuit 29. This digital transmission circuit is a circuit for MIPI A-Phy signal transmission, as known from sensor data transmission. It can therefore be derived from the prior art. An analog signal connection 30 of the digital transmission circuit can be connected to the front-end unit 20, for example, to the mixer 25.A digital signal connection 31 can be electrically connected to the signal cable 27.

[0037] The processor unit 26 can therefore now perform digital transmission and / or digital reception of the digital signal 28. The processor unit 26 can also include a digital mixer 32 to mix the communication data contained in the digital signal 28, for example, from the intermediate frequency band into a base frequency band.

[0038] Alternatively, if mixer 25 is absent, a connection to the amplifier unit 21 can also be provided. "Connection" here means that a mixer signal from mixer 25 is present at analog signal terminal 30, or that an amplifier signal from amplifier unit 21 is present at analog signal terminal 30.

[0039] The at least one vehicle-external device 14 can also have an antenna, and a transceiver circuit can be provided in the at least one vehicle-external device 14 for the operation of the at least one antenna.

[0040] The digital transmission circuit may include an analog-to-digital converter (ADC) for analog-to-digital conversion and / or a digital-to-analog converter (DAC) for digital-to-analog conversion.

[0041] The communication device 11 thus provides a specific digital interface between the antenna 16 with its front end (front end unit 20) on the one hand and the processor unit 26 on the other. This digital interface is the so-called MIPI A-Phy (see, for example, https: / / mipi.org / specifications / a-phy). The A-Phy is currently being developed into a MIPI specification with the aim of defining an interface for the transmission of high data rates from sensors (camera, LiDAR, radar). The described extension with regard to wireless communication services offers the advantage that - that cables can also be saved here, - the same interface is used for sensor data and communication data and - Cost-effective interfaces are available.

[0042] Overall, the examples show how the invention of the MIPI A-Phy standard can provide a digital interface between antennas and network access devices.

Claims

[1] Communication device (11) for radio transmission of communication data (12), with - an antenna (16) for transmitting and / or receiving electromagnetic radio waves (17, 18) representing the communication data (12), and - a front end unit (20) electrically connected to the antenna (16) for amplifying and / or mixing an analog electrical antenna signal (19) containing the communication data (12), and - a processor unit (26) which is configured to generate and / or receive the communication data (12) and / or to exchange it with a digital communication network, wherein - the processor unit (26) is connected to the front end unit (20) via a signal cable (27), characterized by , that at the front end unit side of the signal cable (27) a digital transmission circuit (29) for MIPI A-Phy signal transmission of sensor data is provided and an analog signal terminal (30) of the digital transmission circuit (29) is connected to the front end unit (20) and a digital signal terminal (31) of the digital transmission circuit (29) is connected to the signal cable (27) and the front end unit (20) and the processor unit (26) are coupled to each other by means of a digital signal transmission based on the digital transmission circuit (29) and the processor unit (26) is configured to mix the digital signal (28) by means of a digital mixer (32) for sending out of a baseband and / or for receiving into the baseband. [2] Communication device (11) according to claim 1, wherein the front end unit (20) has an amplifier device (21) for amplifying the antenna signal (19) and the digital transmission circuit (29) in the front end unit (20) is connected to the amplifier device (21). [3] Communication device (11) according to claim 1, wherein the front end unit (20) has a mixer (25) for frequency mixing and the digital transmission circuit (29) in the front end unit (20) is connected to the mixer (25). [4] Communication device (11) according to one of the preceding claims, wherein the digital transmission circuit (29) is configured to perform an analog-to-digital conversion (ADC) of the antenna signal and / or a digital-to-analog conversion (DAC) of the digital signal with a sampling rate greater than 1 gigahertz. [5] Communication device (11) according to one of the preceding claims, wherein the digital transmission circuit (29) is configured to transmit I / Q samples by means of the digital signal (28). [6] Communication device (11) according to one of the preceding claims, wherein the signal cable (27) has a cable length of more than one meter. [7] Communication device (11) according to one of the preceding claims, wherein the processor device (26) is connected to at least one sensor via a respective further signal cable (27), wherein the at least one sensor is configured to send a respective sensor signal to the processor device (26) by means of a respective digital transmission circuit for a MIPI A-Phy signal transmission. [8] Communication device (11) according to one of the preceding claims, wherein the processor device (26) is configured to perform vehicle-to-vehicle communication and / or vehicle-to-X communication using the communication data (12) and to operate a protocol stack for a 5G mobile communication connection and / or a C2X communication connection for this purpose. [9] Motor vehicle (10) with a communication device (11) according to one of the preceding claims.

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