CN111162817B - Method for improving radio frequency dynamic range of OBU (on-board unit), radio frequency front end and OBU - Google Patents
Method for improving radio frequency dynamic range of OBU (on-board unit), radio frequency front end and OBU Download PDFInfo
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- CN111162817B CN111162817B CN201911397233.9A CN201911397233A CN111162817B CN 111162817 B CN111162817 B CN 111162817B CN 201911397233 A CN201911397233 A CN 201911397233A CN 111162817 B CN111162817 B CN 111162817B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
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- G07—CHECKING-DEVICES
- G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
- G07B15/00—Arrangements or apparatus for collecting fares, tolls or entrance fees at one or more control points
- G07B15/06—Arrangements for road pricing or congestion charging of vehicles or vehicle users, e.g. automatic toll systems
- G07B15/063—Arrangements for road pricing or congestion charging of vehicles or vehicle users, e.g. automatic toll systems using wireless information transmission between the vehicle and a fixed station
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Abstract
The application discloses a method for improving the radio frequency dynamic range of an OBU (on-board unit), a radio frequency front end and the OBU. The method comprises the steps of setting a plurality of radio frequency channels, wherein each radio frequency channel comprises an antenna and a branch unit, and the branch unit of at least one radio frequency channel is an attenuation unit; in a waiting awakening stage, selecting a first radio frequency channel combination as a receiving channel; and after waking up, selecting the second radio frequency channel combination as a receiving channel, and selecting the third radio frequency channel combination as a transmitting channel. According to the application, through the combination of different radio frequency channels, the radio frequency dynamic range of the OBU can be greatly improved, so that the OBU is suitable for various application scenes of various vehicle types.
Description
Technical Field
The application relates to the field of electronic toll collection, in particular to a method for improving the radio frequency dynamic range and adaptability of an OBU (on-board unit), a radio frequency front end and the OBU.
Background
An Electronic Toll Collection (ETC) system for expressway mainly uses modern communication technology, Electronic technology, automatic control technology, computer and network technology, etc. to realize the intelligent Electronic system for automatic Toll Collection without stopping vehicles. The system automatically completes the charging process under the condition of not needing a driver to stop and other toll collector operations through the special short-range communication between the Road Side Unit (RSU) and the vehicle-mounted unit (OBU) of the high-speed toll station. The ETC system can greatly improve efficiency.
The OBU on the vehicle is in a low-power consumption waiting awakening state at ordinary times, when the vehicle runs to the ETC lane, the OBU is awakened by 14KHz modulated waves transmitted by the RSU, and after the OBU is awakened, signals are transmitted and received to communicate with the RSU.
At present, the hardware architecture adopted by the OBU mostly adopts the form of an integrated chip, and particularly, the radio frequency front end thereof is mainly composed of an antenna, a matching or filtering circuit and an integrated chip as shown in fig. 1. Because the radio frequency indexes of the integrated chips provided by the original factories of the integrated chips are basically similar, the radio frequency performance of the OBU in the market at present is mainly determined by the radio frequency integrated chips.
And in each OBU design manufacturer, the same antenna and branch are adopted for the awakening link, the transmitting link and the receiving link of the OBU. For radio frequency indexes such as transmitting power, awakening sensitivity, receiving sensitivity and the like, each radio frequency index is changed by changing a control word of a chip register, and the dynamic range of the radio frequency indexes is basically set. However, because some indexes only give the maximum or minimum limit value of the radio frequency parameter in the national standard, and the windshield of different vehicle types attenuates different signals and other factors, the OBU of each manufacturer still has the condition that the radio frequency index does not meet the actual application in the actual application process, but the OBU is difficult to debug in the later stage because the integrated chip is already shaped.
The conventional OBU is difficult to adapt to various application scenes of multiple vehicle types.
Disclosure of Invention
In view of the above, the present application provides a method for improving a radio frequency dynamic range and adaptability of an OBU, a radio frequency front end, and an OBU.
In a first aspect, an embodiment of the present application provides a method for improving a radio frequency dynamic range of an OBU, where the method includes:
setting a plurality of radio frequency channels, wherein each radio frequency channel comprises an antenna and a branch unit, and the branch unit of at least one radio frequency channel is an attenuation unit;
in a waiting awakening stage, selecting a first radio frequency channel combination as a receiving channel;
and after waking up, selecting the second radio frequency channel combination as a receiving channel, and selecting the third radio frequency channel combination as a transmitting channel.
As a specific implementation manner of the embodiment of the present application, the branch unit of at least one radio frequency channel in the second radio frequency channel combination is an attenuation unit.
As a specific implementation manner of the embodiment of the present application, the method further includes:
and determining the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination according to the communication with the RSU by adopting an adaptive algorithm.
As a specific implementation manner of the embodiment of the present application, determining the first radio frequency channel combination, the second radio frequency channel combination, and the third radio frequency channel combination includes:
presetting initial radio frequency parameters when leaving a factory;
when the vehicle runs to an ETC lane, the initial transmitting power of the vehicle is sent to the RSU;
receiving information returned by the RSU, wherein the information comprises transmitting power of the RSU, ranging information, uplink loss and uplink electromagnetic wave loss, the uplink loss is obtained by calculation according to the ranging information L and uplink working frequency F, and the formula is as follows: uplink loss 32.45+20log l (km) +20log f (mhz); the uplink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the uplink electromagnetic wave loss is the initial transmission power of the OBU, the uplink loss, the antenna gain of the RSU, and the actual power of the OBU reaching the RSU, wherein the actual power of the OBU reaching the RSU is measured by a circuit of the RSU;
calculating downlink loss and downlink electromagnetic wave loss according to the received information, wherein the downlink loss is calculated according to the ranging information L and the downlink working frequency f; the formula is as follows: downlink loss 32.45+20log l (km) +20logf (mhz); the downlink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the downlink electromagnetic wave loss is RSU transmitting power-downlink loss + RSU antenna gain-actual power of the RSU reaching the OBU, wherein the actual power of the RSU reaching the OBU is measured by an OBU self circuit;
generating a plurality of groups of uplink electromagnetic wave losses and downlink electromagnetic wave losses in the repeated interaction process of the OBU and the RSU, and finally determining the comprehensive electromagnetic wave loss caused by the front windshield or the environment in the automobile according to a preset algorithm (such as an average value);
and determining actually required radio frequency parameters according to the comprehensive electromagnetic wave loss, and selecting the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination or updating the register configuration in the radio frequency chip according to the initial radio frequency parameters and the actually required radio frequency parameters.
As a specific implementation manner of the embodiment of the present application, the method further includes:
pre-configuring at least one candidate first radio frequency channel combination, at least one candidate second radio frequency channel combination and at least one candidate third radio frequency channel combination;
determining the first, second, and third radio frequency channel combinations, including:
determining a first radio frequency channel combination from the at least one candidate first radio frequency channel combination, determining a second radio frequency channel combination from the at least one candidate second radio frequency channel combination, and determining a third radio frequency channel combination from the at least one candidate third radio frequency channel combination.
In a second aspect, an embodiment of the present application provides a radio frequency front end for an OBU, where the radio frequency front end includes:
a plurality of radio frequency channels, each radio frequency channel comprising an antenna, a branching unit, wherein the branching unit of at least one radio frequency channel is an attenuation unit;
the radio frequency switch control unit is connected with the antenna unit and the integrated chip of the radio frequency channel and is used for controlling the opening or closing of each radio frequency channel, wherein the first radio frequency channel combination is selected as a receiving channel in a waiting awakening stage, the second radio frequency channel combination is selected as a receiving channel after awakening, and the third radio frequency channel combination is selected as a transmitting channel;
and the integrated chip is used for processing the radio frequency signal and completing the conversion between the digital signal and the radio frequency signal.
As a specific implementation manner of the embodiment of the present application, the branch unit of at least one radio frequency channel in the second radio frequency channel combination is an attenuation unit.
In a third aspect, embodiments of the present application provide an OBU employing a radio frequency front end as described above, the OBU being configured to determine the first radio frequency channel combination, the second radio frequency channel combination, and the third radio frequency channel combination according to communication with an RSU using an adaptive algorithm.
As a specific implementation manner of the embodiment of the present application, the OBU is configured to:
presetting initial radio frequency parameters when leaving a factory;
when the vehicle runs to an ETC lane, the initial transmitting power of the vehicle is sent to the RSU;
receiving information returned by the RSU, wherein the information comprises transmitting power of the RSU, ranging information, uplink loss and uplink electromagnetic wave loss, the uplink loss is obtained by calculation according to the ranging information L and uplink working frequency F, and the formula is as follows: uplink loss 32.45+20log l (km) +20log f (mhz); the uplink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the uplink electromagnetic wave loss is the initial transmission power of the OBU, the uplink loss, the antenna gain of the RSU, and the actual power of the OBU reaching the RSU, wherein the actual power of the OBU reaching the RSU is measured by a circuit of the RSU;
calculating downlink loss and downlink electromagnetic wave loss according to the received information, wherein the downlink loss is calculated according to the ranging information L and the downlink working frequency f; the formula is as follows: downlink loss 32.45+20log l (km) +20logf (mhz); the downlink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the downlink electromagnetic wave loss is RSU transmitting power-downlink loss + RSU antenna gain-actual power of the RSU reaching the OBU, wherein the actual power of the RSU reaching the OBU is measured by an OBU self circuit;
generating a plurality of groups of uplink electromagnetic wave losses and downlink electromagnetic wave losses in the repeated interaction process of the OBU and the RSU, and finally determining the comprehensive electromagnetic wave loss caused by the front windshield or the environment in the automobile according to a preset algorithm (such as an average value);
and determining actually required radio frequency parameters according to the comprehensive electromagnetic wave loss, and selecting the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination or updating the register configuration in the radio frequency chip according to the initial radio frequency parameters and the actually required radio frequency parameters.
As a specific implementation manner of the embodiment of the present application, at least one candidate first radio frequency channel combination, at least one candidate second radio frequency channel combination, and at least one candidate third radio frequency channel combination are configured in advance in the OBU;
the OBU is configured to determine a first radio frequency channel combination from the at least one candidate first radio frequency channel combination, determine a second radio frequency channel combination from the at least one candidate second radio frequency channel combination, and determine a third radio frequency channel combination from the at least one candidate third radio frequency channel combination.
In the above embodiment, a plurality of radio frequency channels are provided, each radio frequency channel including an antenna and a branch unit, wherein the branch unit of at least one radio frequency channel is an attenuation unit; in a waiting awakening stage, selecting a first radio frequency channel combination as a receiving channel; and after waking up, selecting the second radio frequency channel combination as a receiving channel, and selecting the third radio frequency channel combination as a transmitting channel. Therefore, through the combination of different radio frequency channels, the radio frequency dynamic range of the OBU can be greatly improved, and the OBU is suitable for various application scenes of various vehicle types. In particular, the above embodiments specifically set the rf channel including the attenuation unit, which leads to a series of problems caused by too high antenna sensitivity in some scenarios.
Drawings
The foregoing and other objects, features and advantages of the application will be apparent from the following more particular descriptions of exemplary embodiments of the application, as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the application.
Fig. 1 shows a schematic structure diagram of a conventional OBU radio frequency front end.
Fig. 2 shows a schematic structural diagram of an OBU radio frequency front end according to an embodiment of the present application.
Fig. 3 shows a schematic structural diagram of an OBU radio frequency front end according to an exemplary embodiment of the present application.
Fig. 4 shows a schematic structural diagram of an OBU radio frequency front end according to an exemplary embodiment of the present application.
Fig. 5 shows a flow diagram of an OBU automatic update and calibration according to an exemplary embodiment of the present application.
Detailed Description
Preferred embodiments of the present application will be described in more detail below. While the following describes preferred embodiments of the present application, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein.
The application provides a method for improving the radio frequency dynamic range of an OBU, which comprises the following steps:
setting a plurality of radio frequency channels, wherein each radio frequency channel comprises an antenna and a branch unit, and the branch unit of at least one radio frequency channel is an attenuation unit;
in a waiting awakening stage, selecting a first radio frequency channel combination as a receiving channel;
and after waking up, selecting the second radio frequency channel combination as a receiving channel, and selecting the third radio frequency channel combination as a transmitting channel.
The first, second and third radio frequency channel combinations are used to distinguish different radio frequency channel combinations, and are not intended to be used to illustrate that the three radio frequency channel combinations are each specific. In some applications, the three selected combinations of radio frequency channels are different; in other applications, they may all be the same, or some two may be the same.
Aiming at different application scenes and vehicle types, all radio frequency channels can be combined to achieve different radio frequency performances and meet the requirements of the actual situation. The system can improve the radio frequency performance, further increase the dynamic range of the system and has self-adaptability.
In one example, the branching unit of at least one radio frequency channel of the second radio frequency channel combination is an attenuation unit.
The inventor intensively researches and discovers that the awakening sensitivity range of chips on the market is-40 dbm-50 dbm and the receiving sensitivity range is-70-80 dbm, but the maximum value of the OBU receiving sensitivity is not limited in the national standard requirements, so that the awakened OBU receiving sensitivity is often too high in practical application. Therefore, when the vehicle is through the ETC lane and the OBU is awakened up the back, because OBU receiving sensitivity is too high, receive the information of being close to the ETC lane RSU easily, lead to OBU and be close to the ETC RSU and communicate. By including the attenuation branch in the second radio frequency channel combination, the problem caused by the high sensitivity of the OBU after awakening can be avoided.
In one example, the OBU may employ an adaptive algorithm to determine the first, second, and third radio frequency channel combinations based on communications with the RSU.
Specifically, the OBU may first transmit its initial transmit power to the RSU;
then receiving information returned by the RSU, wherein the information comprises transmitting power of the RSU, ranging information, uplink loss and uplink electromagnetic wave loss, the uplink loss is obtained by calculation according to the ranging information L and the uplink working frequency F, and the formula is as follows: uplink loss 32.45+20log l (km) +20log f (mhz); the uplink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the uplink electromagnetic wave loss is the initial transmission power of the OBU, the uplink loss, the antenna gain of the RSU, and the actual power of the OBU reaching the RSU, wherein the actual power of the OBU reaching the RSU is measured by a circuit of the RSU;
then, calculating downlink loss and downlink electromagnetic wave loss according to the received information, wherein the downlink loss is calculated according to the ranging information L and the downlink working frequency f; the formula is as follows: downlink loss 32.45+20log l (km) +20logf (mhz); the downlink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the downlink electromagnetic wave loss is RSU transmitting power-downlink loss + RSU antenna gain-actual power of the RSU reaching the OBU, wherein the actual power of the RSU reaching the OBU is measured by an OBU self circuit;
generating a plurality of groups of uplink electromagnetic wave losses and downlink electromagnetic wave losses in the repeated interaction process of the OBU and the RSU, and finally determining the comprehensive electromagnetic wave loss caused by the front windshield or the environment in the automobile according to a preset algorithm (such as an average value);
and finally, determining the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination according to the comprehensive electromagnetic wave loss.
At least one candidate first radio frequency channel combination, at least one candidate second radio frequency channel combination and at least one candidate third radio frequency channel combination may be preset for a vehicle type and the like before the OBU is issued. In practical applications, the OBU may determine the first radio frequency channel combination from at least one candidate preconfigured first radio frequency channel combination, determine the second radio frequency channel combination from at least one candidate second radio frequency channel combination, and determine the third radio frequency channel combination from at least one candidate third radio frequency channel combination.
Fig. 5 shows a flow diagram of an OBU automatic update and calibration according to an exemplary embodiment of the present application. As shown, the OBU automatic update and calibration includes steps 501-504.
Step 501, presetting initial radio frequency parameters when an OBU leaves a factory;
502, when the vehicle runs to an ETC lane, the OBU calculates to obtain a comprehensive electromagnetic wave loss value, and a specific calculation method can be referred to above;
and step 504, adjusting on the basis of the initial radio frequency parameters according to actually required radio frequency parameters to select the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination or update register configuration in the radio frequency chip, so that the radio frequency parameters of the OBU are rationalized.
A specific example is given here. For example, the preset awakening sensitivity of the OBU is-45 dBm when the OBU leaves the factory, when a vehicle with the OBU runs to an ETC lane, the comprehensive electromagnetic wave loss value is obtained according to the method: 9dB, it can be seen that under the vehicle model and the environment inside the vehicle, the wake-up sensitivity of the OBU should be set to-45 dBm-9 dBm-54 dBm, and the OBU can combine the radio frequency channels or modify the register configuration of the integrated chip by itself, so that the wake-up sensitivity of the OBU reaches-54 dBm.
Aiming at high-grade cars, due to the fact that the front windshield of the car attenuates signals greatly, when the car passes through an ETC lane, the OBU is required to have high awakening sensitivity, and a common integrated chip cannot meet the requirements. According to the application, two OBU radio frequency channels may be employed, namely: the two branch units and the antenna form a small-sized antenna array to improve antenna gain and improve OBU awakening sensitivity.
The OBU is used for preventing the vehicle OBU from being communicated with an adjacent lane to cause false deduction or excessive deduction due to overhigh receiving sensitivity.
Two specific application examples according to the present application are given below.
Application example 1
This application example mainly aims at the problem that ordinary vehicle OBU practical application in-process, OBU awakens sensitivity normally, and receiving sensitivity is too high.
When the vehicle that is equipped with the OBU went to the ETC lane, the OBU awakens up the back, and the OBU can carry out the transmission and the receipt of signal, because the present OBU chip in the market exists the too high problem of receiving sensitivity, and the OBU can communicate with the ETC lane on next door this moment. The information of the lane ETC lane RSU is received easily, and the OBU is communicated with the lane ETC RSU.
The application example shown in fig. 3 mainly comprises two radio frequency channels, a radio frequency channel 3-1 and a radio frequency channel 3-2. The radio frequency channel 3-1 includes: antenna 1: 3-10 and branching unit 1: 3-11. Wherein, antenna 1: the gain is 1dB from 3 to 10, and the polarization mode is circular polarization; branching unit 1: and 3-11, the attenuator is a PI type attenuator, the attenuation value of the PI type attenuator is 20dB, and the PI type attenuator mainly comprises a resistor R1 of 60.4 ohms, a resistor R2 of 249 ohms and a resistor R3 of 60.4 ohms. The radio frequency channel 3-2 includes: an antenna 2: 3-20 and branching unit 2: 3-22. Wherein, the antenna: 3-20 gain is 3dB, and the polarization mode is circular polarization; the branching unit 2: 3-22, mainly composed of a filter circuit, wherein the filter adopts a high-pass filter, mainly filters signals below 5GHz, and has an insertion loss of 1 dB. The radio frequency switch controller 3-3 adopts a single-pole double-throw switch and can be configured to be respectively connected with the radio frequency channel 1: 3-1 and radio frequency channel 2: 3-2 are communicated. The other end of the radio frequency switch controller 3-3 is connected with the integrated chip 3-4.
Aiming at the conventional scene, the wake-up sensitivity dynamic range is-40 to-50 dBm and the receiving sensitivity range is-70 to-80 dBm due to the integrated chip on the market. The general OBU configuration requires a reception sensitivity higher than the wake-up sensitivity by about 10dB, for example, when the wake-up sensitivity is-45 dBm, the reception sensitivity is required to be-55 dBm. To meet the above requirements, it is difficult to satisfy the requirements only by the configuration of the integrated chip. According to the application example, when the OBU is in a waiting wakeup mode, the radio frequency switch 3-3 is communicated with the integrated chip 3-4 and the radio frequency channel 3-2, and the OBU works in the radio frequency channel 2: 3-2 mode, where the wake-up sensitivity is-45 dBm in this channel. When the OBU is awakened, the radio frequency front-end switch 3-3 is rapidly communicated with the integrated chip 3-4 and the radio frequency channel 3-1, and enters the radio frequency channel 1: 3-1 mode. Since the radio frequency channel 1: 3-1, a low gain antenna 3-10 is used, and branch 1: 3-11, a PI type attenuator is introduced, so that when the OBU is switched to the channel 3-1, the receiving sensitivity is reduced by about 20dB, the dynamic range is about-50-60 dBm at the moment, and the requirement of-55 dBm can be completely met through the internal register configuration of the integrated chip 3-4. When the OBU transmits signals, a radio frequency channel can be selected according to actual conditions, and then the control words of the 3-4 chips of the OBU integrated chip are changed in a matched mode. In the application example, the transmission channel is a radio frequency channel 3-2, and when the OBU transmits a signal, the radio frequency switch 3-3 connects the integrated chip 3-4 and the radio frequency channel 3-2.
The application example well solves the problem that the OBU receiving sensitivity is too high in some scenes.
Application example 2
The application example mainly aims at the problem that when the OBU is installed in a high-grade vehicle, the vehicle is difficult to wake up or the wake-up distance is too short after the vehicle runs to an ETC lane due to the fact that the front windshield of the high-grade vehicle attenuates signals greatly.
As shown in fig. 4, the present embodiment includes four rf channels, that is: radio frequency channel 1: 4-1; radio frequency channel 2: 4-2; radio frequency channel 3: 4-3; radio frequency channel 4: 4-4. The first three radio frequency channels, radio frequency channel 1: 4-1, radio frequency channel 2: 4-2 and radio frequency channel 3: 4-3, a wake-up link for the OBU; the last radio frequency channel, i.e. radio frequency channel 4:4-4, used for the receiving link and the transmitting link of the OBU.
The radio frequency channel 4-4 mainly comprises: antenna 4:4-40, branching unit 4: 4-41. The gain of the antenna is 4:4-40 dB, and the polarization mode is a circularly polarized antenna. And the branch unit 4:4-41 is composed of an attenuator circuit, the attenuator adopts a PI type attenuator, the attenuation value of the attenuator is 3dB, and the branch unit mainly comprises a resistor R4 of 294 ohms, a resistor R5 of 17.4 ohms, and a resistor R6 of 294 ohms.
Radio frequency channel 1: 4-1, mainly comprising an antenna 1: 4-10, branching unit 1: 4-11; antenna 1: 4-10, the gain is 6dB, and the polarization mode is a circularly polarized antenna. Branching unit 1: 4-11, which employs a phase compensation circuit. The phase compensation circuit has the functions that in the radio frequency channel 1: 4-1, when combined with other radio frequency paths to form an antenna array, for antenna 1: and 4-10, performing phase compensation.
Radio frequency channel 2: 4-2, mainly comprising an antenna 2: 4-20, branching unit 2: 4-21. An antenna 2: 4-20, the gain is 6dB, and the polarization mode is a circularly polarized antenna. The branching unit 2: 4-21, which employs a phase compensation circuit. The phase compensation circuit has the functions of receiving the radio frequency signal in the radio frequency channel 2: 4-2, in combination with other radio frequency paths, to form an antenna array when the antenna 2 is: and 4-20, performing phase compensation.
Radio frequency channel 3: 4-3, mainly comprising an antenna 3: 4-30, branching unit 3: 4-31. An antenna 3: 4-30, the gain is 6dB, and the polarization mode is a circularly polarized antenna. Branching unit 3: 4-31, which employs a phase compensation circuit. The phase compensation circuit has the functions of providing a signal in the radio frequency channel 3: 4-31, in combination with other radio frequency paths, to form an antenna array for antenna 3: and 4-30, performing phase compensation.
In this embodiment, when the OBU is in the low power consumption wait wakeup state, the rf switch 4-5 connects the integrated chip 4-6 to the three rf channels 4-1, 4-2, 4-3 simultaneously. At this time, the antenna 1: 4-10, antenna 2: 4-20, antenna 3: 4-30 to form an antenna array, wherein the integral gain of the antenna array is about 10.8dB so as to improve the integral awakening sensitivity of the OBU, and the OBU enters a high awakening sensitivity state. When the OBU is awakened, the OBU is switched to a receiving and transmitting link state, namely: the radio frequency switch 4-5 will switch to the radio frequency channel 4-4, and the radio frequency switch 4-5 will connect the radio frequency channel 4-4 and the integrated chip 4-6 together. The radio frequency channel 4-4 meets the requirements of the transmitting and receiving link of the OBU signal, and the OBU transmits and receives the signal and communicates with the RSU in the radio frequency channel 4-4.
The application example is very suitable for scenes with large wake-up signal attenuation, and can well solve the problem of insufficient wake-up sensitivity of the OBU.
Having described embodiments of the present application, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.
Claims (5)
1. A method for increasing the radio frequency dynamic range of an OBU, the method comprising:
setting a plurality of radio frequency channels, wherein each radio frequency channel comprises an antenna and a branch unit, and the branch unit of at least one radio frequency channel is an attenuation unit;
in a waiting awakening stage, selecting a first radio frequency channel combination as a receiving channel;
after awakening, selecting the second radio frequency channel combination as a receiving channel, and selecting the third radio frequency channel combination as a transmitting channel;
determining the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination according to communication with an RSU by adopting an adaptive algorithm;
determining the first, second, and third radio frequency channel combinations, including:
presetting initial radio frequency parameters when leaving a factory;
when the vehicle runs to an ETC lane, the initial transmitting power of the vehicle is sent to the RSU;
receiving information returned by the RSU, wherein the information comprises transmitting power of the RSU, ranging information, uplink loss and uplink electromagnetic wave loss, the uplink loss is obtained by calculation according to the ranging information L and uplink working frequency F, and the formula is as follows: uplink loss 32.45+20log l (km) +20log f (mhz); the uplink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the uplink electromagnetic wave loss is the initial transmission power of the OBU, the uplink loss, the antenna gain of the RSU, and the actual power of the OBU reaching the RSU, wherein the actual power of the OBU reaching the RSU is measured by a circuit of the RSU;
calculating downlink loss and downlink electromagnetic wave loss according to the received information, wherein the downlink loss is calculated according to the ranging information L and the downlink working frequency f; the formula is as follows: downlink loss 32.45+20log l (km) +20logf (mhz); the downlink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the downlink electromagnetic wave loss is RSU transmitting power-downlink loss + RSU antenna gain-actual power of the RSU reaching the OBU, wherein the actual power of the RSU reaching the OBU is measured by an OBU self circuit;
generating a plurality of groups of uplink electromagnetic wave losses and downlink electromagnetic wave losses in the repeated interaction process of the OBU and the RSU, and finally determining the comprehensive electromagnetic wave loss caused by the front windshield or the environment in the automobile according to a preset algorithm;
and determining actually required radio frequency parameters according to the comprehensive electromagnetic wave loss, and selecting the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination or updating the register configuration in the radio frequency chip according to the initial radio frequency parameters and the actually required radio frequency parameters.
2. The method of claim 1, wherein the branching unit of at least one of the second combination of radio frequency channels is an attenuation unit.
3. The method of claim 1, further comprising:
pre-configuring at least one candidate first radio frequency channel combination, at least one candidate second radio frequency channel combination and at least one candidate third radio frequency channel combination;
determining the first, second, and third radio frequency channel combinations, including:
determining a first radio frequency channel combination from the at least one candidate first radio frequency channel combination, determining a second radio frequency channel combination from the at least one candidate second radio frequency channel combination, and determining a third radio frequency channel combination from the at least one candidate third radio frequency channel combination.
4. An OBU employing a radio frequency front end, the radio frequency front end comprising: a plurality of radio frequency channels, each radio frequency channel comprising an antenna, a branching unit, wherein the branching unit of at least one radio frequency channel is an attenuation unit;
the radio frequency switch control unit is connected with the antenna unit and the integrated chip of the radio frequency channel and is used for controlling the opening or closing of each radio frequency channel, wherein the first radio frequency channel combination is selected as a receiving channel in a waiting awakening stage, the second radio frequency channel combination is selected as a receiving channel after awakening, and the third radio frequency channel combination is selected as a transmitting channel;
the integrated chip is used for processing the radio frequency signal and completing the conversion between the digital signal and the radio frequency signal;
the OBU is configured to determine the first, second, and third radio frequency channel combinations from communications with an RSU using an adaptive algorithm;
the OBU is configured to:
presetting initial radio frequency parameters when leaving a factory;
when the vehicle runs to an ETC lane, the initial transmitting power of the vehicle is sent to the RSU;
receiving information returned by the RSU, wherein the information comprises transmitting power of the RSU, ranging information, uplink loss and uplink electromagnetic wave loss, the uplink loss is obtained by calculation according to the ranging information L and uplink working frequency F, and the formula is as follows: uplink loss 32.45+20log l (km) +20log f (mhz); the uplink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the uplink electromagnetic wave loss is the initial transmission power of the OBU, the uplink loss, the antenna gain of the RSU, and the actual power of the OBU reaching the RSU, wherein the actual power of the OBU reaching the RSU is measured by a circuit of the RSU;
calculating downlink loss and downlink electromagnetic wave loss according to the received information, wherein the downlink loss is calculated according to the ranging information L and the downlink working frequency f; the formula is as follows: downlink loss 32.45+20log l (km) +20logf (mhz); the downlink electromagnetic wave loss caused by the front windshield or the environment in the vehicle is represented by the following formula: the downlink electromagnetic wave loss is RSU transmitting power-downlink loss + RSU antenna gain-actual power of the RSU reaching the OBU, wherein the actual power of the RSU reaching the OBU is measured by an OBU self circuit;
generating a plurality of groups of uplink electromagnetic wave losses and downlink electromagnetic wave losses in the repeated interaction process of the OBU and the RSU, and finally determining the comprehensive electromagnetic wave loss caused by the front windshield or the environment in the automobile according to a preset algorithm;
and determining actually required radio frequency parameters according to the comprehensive electromagnetic wave loss, and selecting the first radio frequency channel combination, the second radio frequency channel combination and the third radio frequency channel combination or updating the register configuration in the radio frequency chip according to the initial radio frequency parameters and the actually required radio frequency parameters.
5. The OBU of claim 4, wherein:
at least one candidate first radio frequency channel combination, at least one candidate second radio frequency channel combination and at least one candidate third radio frequency channel combination are configured in the OBU in advance;
the OBU is configured to determine a first radio frequency channel combination from the at least one candidate first radio frequency channel combination, determine a second radio frequency channel combination from the at least one candidate second radio frequency channel combination, and determine a third radio frequency channel combination from the at least one candidate third radio frequency channel combination.
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| CN114785375B (en) * | 2022-06-14 | 2022-09-20 | 长江信达软件技术（武汉）有限责任公司 | Radio frequency double-carrier awakening system and method |
| CN115954648A (en) * | 2022-12-29 | 2023-04-11 | 北京万集科技股份有限公司 | RSU antenna and electronic toll collection system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101494523A (en) * | 2008-12-30 | 2009-07-29 | 北京握奇数据系统有限公司 | Channel self-adapting method, device and system |
| CN201341134Y (en) * | 2009-02-18 | 2009-11-04 | 深圳鼎识科技有限公司 | Vehicle radio frequency identification wireless base station and radio frequency communication system |
| KR100935657B1 (en) * | 2007-12-11 | 2010-01-07 | (주)코스페이스 | Terminal for vehicle and method for controlling terminal for vehicle |
| CN202041996U (en) * | 2011-03-25 | 2011-11-16 | 深圳市金溢科技有限公司 | Vehicle-mounted unit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104579408B (en) * | 2013-12-19 | 2017-03-29 | 深圳市金溢科技股份有限公司 | Board units OBU and its wake-up receiving circuit |
-
2019
- 2019-12-30 CN CN201911397233.9A patent/CN111162817B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100935657B1 (en) * | 2007-12-11 | 2010-01-07 | (주)코스페이스 | Terminal for vehicle and method for controlling terminal for vehicle |
| CN101494523A (en) * | 2008-12-30 | 2009-07-29 | 北京握奇数据系统有限公司 | Channel self-adapting method, device and system |
| CN201341134Y (en) * | 2009-02-18 | 2009-11-04 | 深圳鼎识科技有限公司 | Vehicle radio frequency identification wireless base station and radio frequency communication system |
| CN202041996U (en) * | 2011-03-25 | 2011-11-16 | 深圳市金溢科技有限公司 | Vehicle-mounted unit |
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