Multi-channel RSU antenna device and control method

Abstract

The invention discloses a multichannel RSU antenna device and a control method, the device comprises a control unit and a plurality of RSU antenna units, and each RSU antenna unit forms a channel; the control unit is connected with the plurality of RSU antenna units through a control bus. By implementing the multi-channel RSU antenna device provided by the invention, a farther identification distance, a wider coverage range and a stronger anti-interference capability can be realized, so that the multi-channel RSU antenna device can better adapt to increasingly complicated traffic environments.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic toll collection systems, and in particular to a multi-channel RSU antenna device and a control method thereof. Background Art

[0002] ETC (Electronic Toll Collection) is a key measure to improve highway traffic efficiency and alleviate traffic congestion. Its core component, the ETC antenna, plays an indispensable role in achieving effective communication with on-board electronic tags and composite pass cards. However, with the increasing complexity and diversity of the traffic environment, the adaptability shortcomings of traditional ETC antennas have gradually become apparent. This type of antenna was originally designed for relatively simple highway toll collection scenarios, where vehicle speeds are relatively constant and lane layouts are relatively regular. However, under current complex traffic conditions, such as the intersection of urban expressways and highways, where vehicle speeds change frequently; and at toll booths with heavy traffic and multiple lanes running in parallel, where vehicle density is high and lane changes are frequent, traditional ETC antennas face unprecedented challenges.

[0003] Faced with these complex application scenarios, the performance limitations of traditional ETC antennas are particularly prominent. On the one hand, due to their limited recognition range and limited signal transmission and reception capabilities, they struggle to effectively identify on-board electronic tags and composite toll cards at distant locations. This limitation increases the risk of information exchange failure, especially when vehicles are traveling at high speeds. This can force vehicles to slow down or even stop for re-identification, severely impacting traffic efficiency. On the other hand, traditional ETC antennas have a narrow coverage range, typically covering only single or dual lanes. In multi-lane toll booths, multiple antennas must be installed to meet demand, which not only increases hardware costs but also makes system installation and maintenance more difficult.

[0004] Therefore, it is necessary to design a new structure to achieve a longer recognition distance, wider coverage and stronger anti-interference ability to better adapt to the increasingly complex traffic environment. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a multi-channel RSU antenna device and a control method.

[0006] In order to solve the above technical problems, the purpose of the present invention is achieved through the following technical solutions: providing a multi-channel RSU antenna device, including: a control unit and several RSU antenna units, wherein each of the RSU antenna units constitutes a channel; the control unit is connected to the several RSU antenna units through a control bus.

[0007] Its further technical solution is: each of the RSU antenna units includes a radio frequency transceiver, a downlink signal amplifier, an uplink signal amplifier, a bandpass filter and a directional antenna; the radio frequency transceiver is connected to the control unit; the radio frequency transceiver is connected to the downlink signal amplifier; the directional antenna is connected to the bandpass filter; the bandpass filter is connected to the uplink signal amplifier; the uplink signal amplifier is connected to the radio frequency transceiver; and the downlink signal amplifier is connected to the directional antenna.

[0008] A further technical solution is: the directional antennas in the plurality of RSU antenna units include circularly polarized array antennas with different coverage directions.

[0009] A further technical solution is: there are four channels, and the four channels correspond to the four directions of the intersection respectively.

[0010] A further technical solution is: the radio frequency transceiver includes a 5.8G transceiver chip with an integrated radio frequency transceiver front end.

[0011] Its further technical solution is: it also includes a PSAM card security encryption and decryption module; the PSAM card security encryption and decryption module is connected to the control unit.

[0012] Its further technical solution is: it also includes a multi-channel radio frequency overcurrent detection module, and the multi-channel radio frequency overcurrent detection module is connected to the control unit.

[0013] Its further technical solution is: it also includes a downlink output power detection module; the downlink output power detection module is connected to the control unit.

[0014] Its further technical solution is: it also includes a multi-channel radio frequency temperature detection module; the multi-channel radio frequency temperature detection module is connected to the control unit.

[0015] In addition, in order to overcome the shortcomings of the prior art, the present invention also provides a control method for the above-mentioned multi-channel RSU antenna device, including: The control unit selects one of the multiple channels to send a BST wake-up signal and sets the other channels to receive the return VST signal; Extract the VST signal of each channel and parse the signal to obtain the ID of the OBU, count the number of parsing failures, and when the number exceeds a certain range, clear the buffered data of the corresponding FIFO storage data buffer and resend the BST wake-up signal; wherein, a FIFO storage data buffer is allocated for each channel; After successful parsing, the current channel number, OBU ID and signal RSSI value are preprocessed and the parsed content is stored in the FIFO storage data buffer; The FIFO storage data buffers of each channel are compared. If the set requirements are met, the current channel is determined to establish a link binding relationship with the OBU ID, the OBU to be traded is locked within the coverage area of the current channel, and the transaction identification or deduction process is continued; if the set requirements are not met, the OBU ID obtained by parsing is discarded, and the control unit is re-executed to select one of the multiple channels to send a BST wake-up signal, and set other channels to receive the return VST signal.

[0016] Compared with the existing technology, the present invention has the following advantages: by integrating a control unit with multiple RSU antenna units, each of which forms an independent channel and is interconnected via a control bus, the present invention achieves a longer recognition distance, wider coverage, and stronger anti-interference capabilities. The device utilizes multiple RSU antenna units working in collaboration, not only expanding signal coverage and enhancing signal strength, but also effectively reducing adjacent channel interference and external electromagnetic interference through intelligent scheduling and optimization of the operating frequency and time of each channel, ensuring efficient and stable operation in complex traffic environments. This in turn improves the accuracy and response speed of vehicle identification, better adapting to the needs of modern traffic management.

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic block diagram of a multi-channel RSU antenna device provided in an embodiment of the present invention; Figure 2 A flowchart of a control method for a multi-channel RSU antenna device provided by an embodiment of the present invention; Description of the symbols in the figure: 10. Control unit; 20. RSU antenna unit; 21. RF transceiver; 22. Downlink signal amplifier; 23. Uplink signal amplifier; 24. Bandpass filter; 25. Directional antenna; 30. Control bus; 40. PSAM card security encryption and decryption module; 50. Multi-channel RF temperature detection module; 60. Downlink output power detection module; 70. Multi-channel RF overcurrent detection module. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0022] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0023] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0024] ETC antennas, core components of electronic toll collection systems, play a key role in improving highway traffic efficiency. However, as traffic environments become increasingly complex, their adaptability and performance limitations are becoming increasingly apparent. Traditional ETC antennas were originally designed for simple highway toll collection scenarios. However, facing today's complex traffic conditions, such as intersections between urban expressways and highways and multi-lane toll booths, their limited recognition range and narrow coverage make it difficult to effectively communicate with vehicles traveling at high speeds or at long distances. This increases the risk of information exchange failures, impacting traffic efficiency, and the need to install multiple antennas to cover multiple lanes increases costs and maintenance. Therefore, the performance bottleneck of traditional ETC antennas in complex application scenarios urgently needs to be overcome.

[0025] To this end, an embodiment of the present invention provides a multi-channel RSU antenna device to achieve a longer recognition distance, a wider coverage range, and a stronger anti-interference capability to better adapt to the increasingly complex traffic environment.

[0026] Specifically, the system's structural design includes a control unit 10 and multiple RSU (Road Side Unit) antenna units, with each antenna unit acting as an independent channel, achieving wider coverage. Each RSU antenna unit 20 is equipped with a radio frequency transceiver 21, a signal amplifier, a bandpass filter 24, and a directional antenna 25. It utilizes a 5.8G transceiver chip with an integrated radio frequency front-end, enhancing recognition range and signal processing capabilities. Furthermore, the system incorporates features such as a PSAM (Purchase Secure Access Module) card security encryption and decryption module, multi-channel radio frequency overcurrent detection, downlink output power detection, and temperature detection, further enhancing system stability and anti-interference capabilities. The control method utilizes a selective channel to send a wake-up signal, analyzes VST (Vehicle Signaling Transmission) signals, and locks onto a target OBU (On-Board Unit) within a specific channel to complete transactions or deductions. This ensures efficient and accurate information exchange, adapting to complex traffic conditions and effectively improving the efficiency and service quality of the ETC system.

[0027] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0028] See also Figure 1 A multi-channel RSU antenna device includes: a control unit 10 and a plurality of RSU antenna units 20, wherein each RSU antenna unit 20 constitutes a channel; the control unit 10 is connected to the plurality of RSU antenna units 20 via a control bus 30.

[0029] In this embodiment, each RSU antenna unit 20 constitutes an independent communication channel. The entire device is designed to improve data transmission efficiency, receiving sensitivity, and device stability and reliability through an efficient multi-channel design.

[0030] The control unit 10 is a core component responsible for managing the operating status of each RSU antenna unit 20. It communicates with each RSU antenna unit 20 via a serial bus (such as an SPI interface) to implement time-division multiplexing control of each channel. Furthermore, the control unit 10 integrates a PSAM card security encryption and decryption module 40 to ensure data security.

[0031] Each RSU antenna unit 20 forms an independent communication channel, consisting of a transmit link, a receive link, an RF transceiver 21, and a directional antenna 25. These components work together to transmit and receive signals. To improve receive sensitivity and reduce co-channel crosstalk, metal shielding is used between channels, and fast transmit / receive switching (<200 μs) is achieved within a single channel.

[0032] The use of four independent transceiver channels allows for simultaneous coverage of multiple lanes, effectively improving the reception success rate and the device's processing power. Of course, other embodiments may allow for a greater or different number of transceiver channels. An integrated current sensing chip and logarithmic detector are used for overcurrent protection of the amplifier drain power supply and precise monitoring of transmit power, respectively. Real-time temperature monitoring via the I²C interface ensures stable operation of the device under varying environmental conditions. Diversity signal reception and transmission are supported, enhancing the device's ability to combat interference and improving communication quality. A polling mechanism prioritizes critical tasks, ensuring efficient protocol reception and data upload. By analyzing the received VST signal strength (RSSI value), a priority list is established to determine the optimal communication path, thereby targeting the OBU tag to be traded.

[0033] The control unit 10 controls four DSRC radio frequency transceiver front-ends via the SPI interface. Each front-end includes a complete transmit and receive chain and can operate independently. To prevent adjacent channel interference and improve scanning efficiency, two threads are designed to simultaneously scan different channels. Simultaneous scanning with two antennas arranged in back-to-back parallel configurations further improves efficiency and reduces the risk of interference. Scanning strategies are automatically adjusted when vehicles enter or leave a certain area, ensuring continuity and accuracy during the transaction process.

[0034] In summary, this multi-channel RSU antenna device design not only enhances the overall performance of the device, but also provides a more reliable and efficient solution for the electronic toll collection system through innovative design concepts and technical means.

[0035] In one embodiment, see Figure 1 Each of the above-mentioned RSU antenna units 20 includes a radio frequency transceiver 21, a downlink signal amplifier 22, an uplink signal amplifier 23, a bandpass filter 24 and a directional antenna 25; the radio frequency transceiver 21 is connected to the control unit 10; the radio frequency transceiver 21 is connected to the downlink signal amplifier 22; the directional antenna 25 is connected to the bandpass filter 24; the bandpass filter 24 is connected to the uplink signal amplifier 23; the uplink signal amplifier 23 is connected to the radio frequency transceiver 21; and the downlink signal amplifier 22 is connected to the directional antenna 25.

[0036] In one embodiment, each RSU antenna unit 20 is designed to achieve efficient data transmission and reception while ensuring device stability and reliability. The following is a detailed description of each RSU antenna unit 20 based on the information you provided: Each RSU antenna unit 20 mainly includes the following components: The RF transceiver 21, as the core component, is responsible for transmitting and receiving RF signals. It integrates functions such as an ASK modem, FM0 codec, low-noise amplifier (LNA), and automatic gain control (AGC). It also features internal HDLC CRC calculation and supports both SPI and direct data interfaces, demonstrating its high level of integration.

[0037] The downlink signal amplifier 22 is used to enhance the signal strength in the downlink to ensure that the signal does not attenuate too much due to distance or interference during transmission. The amplifier is usually located after the RF transceiver 21 and before the directional antenna 25 to ensure effective signal transmission.

[0038] The uplink signal amplifier 23 is optimized for the uplink and is used to amplify the weak signal from the vehicle-mounted unit for subsequent processing. This amplifier is connected between the bandpass filter 24 (BPF) and the RF transceiver 21 to ensure the quality of the received signal.

[0039] The bandpass filter 24 is used to filter out unwanted frequency components, allowing only signals in a specific frequency band to pass, thereby reducing interference and improving receiving sensitivity. Each RSU antenna unit 20 is equipped with an independent bandpass filter 24 to meet the requirements of its operating frequency band.

[0040] The directional antenna 25 is designed as a circularly polarized array antenna, which can cover different directions and provide multi-directional communication capabilities. These antennas are respectively connected to their own bandpass filters 24 to form independent working channels.

[0041] The RF transceiver 21 is connected to the control unit 10 via a serial bus (such as an SPI interface), so that the control unit 10 can send instructions and receive status feedback.

[0042] The transmitting port of the RF transceiver 21 is connected to the downlink signal amplifier 22, and the amplified signal is then transmitted to the directional antenna 25 for broadcasting.

[0043] The signal received by the directional antenna 25 is first filtered by the bandpass filter 24 to remove unnecessary frequency components, and then sent to the uplink signal amplifier 23 for amplification.

[0044] The output port of the uplink signal amplifier 23 is connected to the receiving port of the RF transceiver 21, and the amplified signal is sent back to the RF transceiver 21 for demodulation and other processing.

[0045] The control unit 10 selects one or more RSU antenna units 20 for data transmission as needed. The selected unit generates a corresponding RF signal through the RF transceiver 21. This signal is amplified by the downlink signal amplifier 22 and then transmitted by the directional antenna 25. When an onboard unit responds, the directional antenna 25 captures the return signal and transmits it to the bandpass filter 24 for filtering. The filtered signal enters the uplink signal amplifier 23 for amplification and ultimately reaches the RF transceiver 21 for demodulation and data analysis.

[0046] To reduce the impact of co-channel crosstalk, metal shielding is used between channels. Furthermore, the device implements a single-transmit, multiple-receive mode, meaning it can quickly switch to other channels to receive data within a time window, avoiding data loss caused by a single channel being occupied.

[0047] This design not only improves data transmission efficiency and accuracy in multi-lane scenarios, but also enhances the reliability and stability of the entire ETC system. By flexibly configuring the components and their connections, the RSU antenna unit 20 can maintain good performance in complex traffic environments.

[0048] In one embodiment, see Figure 1 The above-mentioned radio frequency transceiver 21 includes a 5.8G transceiver chip with an integrated radio frequency transceiver front end.

[0049] In one embodiment, the RF transceiver 21 uses an integrated 5.8G transceiver chip as the core component of the RF transceiver front end. This design not only simplifies the system architecture, but also improves overall performance and reliability.

[0050] The functions of the 5.8G transceiver chip integrated with the RF transceiver front end are as follows: ASK modems are used to implement amplitude shift keying (ASK) modulation and demodulation, which is a common digital signal modulation method suitable for short-distance communications.

[0051] The FM0 codec supports the FM0 encoding format, which is commonly used in wireless communication fields such as RFID. It has high data transmission efficiency and anti-interference capabilities.

[0052] The built-in low-noise amplifier (LNA) can effectively improve the sensitivity of the receiver, ensuring good reception performance even in weak signal environments.

[0053] Automatic Gain Control (AGC) automatically adjusts the gain to adapt to different signal strengths, thereby maintaining the consistency of the output signal level and improving the stability and reliability of the device.

[0054] Supports cyclic redundancy check in the advanced data link control protocol to detect and correct data transmission errors and ensure data integrity.

[0055] The SPI interface and direct data interface provide flexible interface options for efficient data exchange and control with other system components.

[0056] Integrating multiple key components such as the modem, codec, LNA, and AGC into a single chip reduces the number of external components, reduces device complexity, and also reduces physical size. The integration of high-performance LNA and AGC enables the RF transceiver 21 to maintain excellent reception performance over a wider range of signal strengths. The combination of ASK modulation and FMO encoding, coupled with a built-in CRC checksum mechanism, ensures high-speed and reliable data transmission. A standardized SPI interface facilitates connection to a main control unit or other peripheral devices, simplifying hardware design and software development.

[0057] This integrated 5.8G RF transceiver 21 is ideally suited for multi-channel RSU antenna systems in ETC (Electronic Toll Collection) systems. It meets the requirements for fast switching and multi-tag transaction processing while ensuring data security and accuracy. Furthermore, its compact design makes it suitable for installation in space-constrained environments such as toll booths and parking entrances, enhancing overall system deployment flexibility and operational efficiency.

[0058] In summary, the RF transceiver 21 using the integrated 5.8G transceiver chip provides an efficient and reliable solution for the multi-channel RSU antenna device, significantly enhancing the performance and applicability of the device.

[0059] In one embodiment, see Figure 1 The control bus 30 mentioned above includes a SPI (Serial Peripheral Interface) bus.

[0060] In one embodiment, the control bus 30 utilizes the SPI bus to facilitate communication between the main control unit and various components. The SPI bus is a high-speed, full-duplex synchronous serial communication interface suitable for short-range inter-chip communication. In this device, the control unit 10 controls four DSRC (Dedicated Short Range Communication) radio frequency transceiver front-ends via the SPI bus, making data transmission more efficient and stable. This design ensures fast switching between channels and secure transactions for multiple tags.

[0061] In one embodiment, see Figure 1The multi-channel RSU antenna device further includes a PSAM card security encryption and decryption module 40 ; the PSAM card security encryption and decryption module 40 is connected to the control unit 10 .

[0062] The PSAM card security encryption and decryption module 40 is directly connected to the control unit 10. The PSAM card is primarily used to handle payment-related encryption and decryption operations, ensuring data security during transactions. Specifically, the PSAM card extension supports multiple PSAM cards, which can provide encryption and decryption services for multiple tags simultaneously, enhancing the device's processing power and security.

[0063] In one embodiment, see Figure 1 The above-mentioned multi-channel RSU antenna device further includes a multi-channel RF over-current detection module 70 , which is connected to the control unit 10 .

[0064] To protect the device from current overloads, a multi-channel RF overcurrent detection module 70 is also connected to the control unit 10. This module uses a current sensing chip to monitor the current in the amplifier's drain power supply. If the current exceeds a preset value, it reports the abnormal current value via I²C communication and outputs a low-level alarm signal to notify the control unit 10 to take appropriate measures, such as cutting off the power supply or adjusting the operating state, to prevent damage to the device.

[0065] In one embodiment, see Figure 1 The above-mentioned multi-channel RSU antenna device further includes a downlink output power detection module 60 ; the downlink output power detection module 60 is connected to the control unit 10 .

[0066] In this embodiment, a downlink output power detection module 60 is integrated to monitor and adjust the output power of the transmit link. Located at the coupling end of the transmit link's microstrip coupler, this module employs a logarithmic detector chip for precise power measurement. Its operating frequency range covers 100 to 6000 MHz, with a logarithmic error accuracy of ±1 dB. By monitoring output power in real time, the device can adjust the transmission intensity as needed, ensuring effective signal coverage while avoiding interference or other issues caused by excessive transmission.

[0067] In one embodiment, see Figure 1 The above-mentioned multi-channel RSU antenna device further includes a multi-channel RF temperature detection module 50 ; the multi-channel RF temperature detection module 50 is connected to the control unit 10 .

[0068] In one embodiment, considering that temperature fluctuations may affect the performance of electronic components, a multi-channel RF temperature detection module 50 is also provided. This module is also connected to the control unit 10 and uploads temperature data via the I²C interface. Based on this data, operating parameters are adjusted, such as increasing heat dissipation measures or reducing power consumption, to maintain optimal operating conditions. This is crucial to ensuring stable operation of the device under various environmental conditions.

[0069] In summary, by integrating the SPI bus, the PSAM card security encryption and decryption module 40, the multi-channel RF overcurrent detection module 70, the downlink output power detection module 60 and the multi-channel RF temperature detection module 50, the multi-channel RSU antenna device not only improves the data transmission efficiency and the reception success rate, but also enhances the security, reliability and adaptability of the device, and can provide efficient services in complex traffic environments.

[0070] In one embodiment, see Figure 1 The directional antennas 25 in the aforementioned RSU antenna units 20 include circularly polarized array antennas with different coverage directions. This design is intended to meet the requirements for efficient and reliable communication in a multi-lane environment.

[0071] Each RSU antenna unit 20 includes multiple directional antennas 25, which are designed with circular polarization. An important advantage of circular polarization antennas is that they can reduce multipath interference caused by reflections, which is particularly important for stable communication of vehicles moving at high speeds.

[0072] To achieve effective coverage of multiple lanes, these circularly polarized array antennas are set up to face different directions. This means that each antenna is responsible for covering a specific area or lane, ensuring that signals from different directions can be effectively received and transmitted.

[0073] In this embodiment, four RF transceiver channels are used to implement a 4T4R (four transmit, four receive) operating mode via four independent RF transceivers 21. Each RF transceiver 21 is connected to a circularly polarized array antenna with a specific coverage direction, enabling optimized signal transmission for different lanes.

[0074] In one embodiment, there are four channels, and the four channels correspond to the four directions of the intersection respectively.

[0075] To increase isolation between channels and prevent co-channel crosstalk, each channel utilizes an independent shielded cavity. This not only improves device stability but also enhances reception sensitivity and data transmission success rate. The control unit 10 polls the status of the four channels in real time and determines the optimal communication channel based on received signal strength (RSSI) and other parameters. Once the optimal channel is determined, it locks onto that channel to complete specific transactions, such as billing operations.

[0076] By utilizing circularly polarized array antennas with varying coverage directions, this embodiment provides wider and more stable signal coverage in multi-lane environments. The four-way reception significantly improves receiver sensitivity and reduces the risk of data loss due to weak signals. A fast switching mechanism and intelligent selection algorithm ensure efficient processing of transaction requests from multiple tags, even in high-traffic environments.

[0077] In summary, in one embodiment, a carefully designed multi-channel ETC antenna system utilizes circularly polarized array antennas with different coverage directions, which not only achieves effective coverage of multiple lanes but also greatly improves the reliability and efficiency of the entire device.

[0078] The structure of this embodiment achieves multi-lane coverage and enhances device performance by improving receive sensitivity and success rate. Each channel is designed with a transmit link (including a power amplifier (PA) and a temperature-compensated attenuator) and a receive link (including a low-noise amplifier (LNA) and a 24BPF bandpass filter). Operating states are switched using time-division control signals. Metal shielding is used between links to reduce co-channel crosstalk. Deduplication processing is performed within the same receive window to prevent duplicate data uploads.

[0079] A current sensing chip monitors the power amplifier drain power supply and reports the current value via I²C communication. If the current exceeds the set value, a low-level alarm signal is output. A transmit power detection circuit based on a microstrip coupler is designed for the transmit chain, employing a logarithmic detector chip operating in the 100-6000 MHz frequency band with a ±1dB error. Temperature measurement data is uploaded to the main MCU via the I²C interface to ensure stable operation. Using a time-sharing operation mode, circuit isolation is not required for a single channel. The single-channel transmit / receive switching time is optimized to less than 200µs, improving data transmission efficiency. Furthermore, a single-receive mode is adopted to minimize the risk of frame loss. This achieves signal diversity reception and transmission, improving signal reliability and stability. By comprehensively processing the signals received by multiple antennas, interference is effectively reduced and communication quality is improved. Furthermore, the multi-antenna design enables spatial multiplexing, increasing system capacity and transmission efficiency. In multi-lane toll booths, vehicles in different lanes can communicate with the antennas simultaneously, enhancing the processing capabilities of the toll collection system.

[0080] The four-channel transmission and reception utilize four independent RF transceivers 21, achieving a 4T4R operating mode. Four independent shielded cavities enhance inter-channel isolation. These four RF channels are connected via RF cables to four circularly polarized array antennas with different coverage directions, meeting multi-directional communication requirements. A single-chip receiver integrates an LNA and AGC, achieving high receive sensitivity and a wide dynamic range. The device utilizes a single-transmit, multiple-receive mode, enabling real-time, high-speed channel scanning and cyclic wakeup of vehicle tags in multiple directions.

[0081] The structure of this embodiment is used to lock multiple frames between channels and transaction links as follows: A BST (Beacon Signal Transmission) wake-up signal is sent to wake up the on-board units (OBUs) within the coverage area; VST (Vehicle Status Transmission) response signals are received from multiple OBUs, containing OBU status information; the received VST signals are parsed, the OBU ID and RSSI values are extracted, and these data are stored in a FIFO buffer; and the currently stored data is checked to see if it meets the preset priority criteria. If so, the next step is continued; otherwise, the process returns to the step "Receiving VST (Vehicle Status Transmission) response signals from multiple OBUs containing OBU status information." If the priority criteria are met, the device stores data such as the current channel number, OBU ID, and RSSI value; and checks to see if the FIFO buffer already has N data items stored. If N data has not been received, continue to receive more VST signals; if N data has been received, proceed to the next step; count the number of parsing failures, if it exceeds a certain range, clear the FIFO buffer data and resend the BST wake-up signal; if it does not exceed the range, clear the cached data and prepare for the next step of processing; lock the current channel and establish a link binding relationship with the corresponding OBU to complete the transaction identification or deduction process.

[0082] Specifically, the master controller selects one of n available channels to send a BST signal, while simultaneously setting the other n-1 channels to receive mode to prepare for the return VST signal. The received VST signal is extracted from each channel and parsed to determine the OBU ID. If the parsing failure count exceeds a set limit, the data in the FIFO buffer is cleared and the BST signal is resent to restart the process. Each channel is assigned an independent FIFO data buffer for temporary storage of received data. Once the VST signal is successfully parsed, the current channel number, the parsed OBU ID, and the signal strength RSSI value are preprocessed and stored in the corresponding FIFO buffer. The data in each channel's FIFO buffer is compared based on pairwise similarity, and priority is determined by comparing the RSSI values of the received VST signals. If the conditions are met (i.e., a channel with the highest RSSI value), a link binding is established between that channel and the corresponding OBU ID, locking the OBU to be traded within its coverage area and continuing the transaction identification or fee deduction process. Otherwise, the BST signal is resent.

[0083] The channel switching process: directional antenna 25 is powered on and transmits a BST wake-up signal. Simultaneously, multiple threads are launched to monitor each RF channel. A check is performed to see if any vehicle tag responds to the BST signal. If so, the process proceeds to the next step. If not, the BST signal is sent again. A determination is made as to whether a transaction channel has been locked for the current vehicle tag. If so, the transaction proceeds directly. If not, further processing is required. One thread establishes a transaction link with the current vehicle tag and continues the transaction process. The remaining threads continue scanning other channels to confirm that the transaction for the current vehicle tag has successfully completed. The process ends after all necessary transaction processes are complete.

[0084] Specifically, the ETC fusion antenna front end consists of four RF transceiver channels, providing multi-directional coverage. When a vehicle tag enters the antenna coverage area from the coverage direction of any channel, the main control polls these four channels in sequence to attempt to wake up the vehicle tag. To further improve channel scanning efficiency, the main control is designed with two threads that can scan two channels simultaneously, which can theoretically increase efficiency by 50%. To avoid interference from adjacent channels, the two channels performing simultaneous frequency scanning are preferably arranged with two antennas arranged in parallel facing back to back. Once a tag reply is received in a certain area, subsequent communications will continue to use that area.

[0085] Based on the VST multi-frame tag locking process, the current tag's transaction area can be automatically locked, while other threads continue to poll and scan the remaining channels. When the antenna automatically switches to start trading with the tag, if it finds that no tag data has been received for a period of time, it needs to be restored to the previous area to prevent the problem of mis-switching caused by incorrect tag transaction channel locking.

[0086] In this embodiment, when the vehicle tag enters the antenna coverage area from any channel coverage direction, the main control polls the four channels in sequence to wake up the vehicle tag. To further improve the channel scanning efficiency, the main control is designed with two threads that can scan two channels at the same time, which improves the efficiency by 50%. In order to reduce interference from adjacent channels, the two channels that scan the frequency at the same time give priority to two antennas arranged in parallel with their backs to each other. Once a tag reply is received in a certain area, the area will be used for subsequent communication. The transaction area of the current tag is automatically locked according to the VST multi-frame tag locking process; other threads continue to rotate and scan other channels. When the antenna automatically switches to follow the tag for transaction, if no tag data is received for a period of time, it is necessary to restore to the previous area to prevent incorrect switching caused by tag transaction channel locking errors.

[0087] By designing a multi-channel ETC antenna, the four channel coverage areas are flexibly integrated into a single area, enabling rapid switching of multiple RF channels and secure transactions for multiple tags. This achieves multi-lane coverage and improves reception sensitivity and success rate through four-way reception.

[0088] The device of this embodiment achieves effective coverage of multiple lanes and improves signal reception sensitivity and success rate through an enhanced four-way reception method. Each channel consists of a transmit link and a receive link. The transmit link includes a power amplifier and a temperature-compensated attenuator, while the receive link includes a low-noise amplifier and a bandpass filter 24. Time division multiplexing technology is used to control the operating status of each link, ensuring that only one link is active at any given time.

[0089] To minimize co-channel interference, metal shielding is installed between each link. When multiple receiving chips receive signals simultaneously, the signal that first triggers the reception interrupt is prioritized and transmitted to the corresponding lane. Furthermore, within the same reception cycle, anti-duplication measures are implemented. If detected data has already been successfully received and uploaded, the duplicate data is directly discarded, thus ensuring data uniqueness and validity.

[0090] This design not only improves the overall performance and reliability of the device, but also optimizes resource utilization and ensures efficient and accurate data transmission.

[0091] The multi-channel RSU antenna device described above integrates a control unit 10 with multiple RSU antenna units 20, each of which forms an independent channel and is interconnected via a control bus 30, thereby achieving a longer recognition distance, wider coverage, and stronger anti-interference capabilities. By utilizing multiple RSU antenna units 20 working together, this device not only expands signal coverage and enhances signal strength, but also effectively reduces adjacent channel interference and external electromagnetic interference through intelligent scheduling and optimization of the operating frequency and time of each channel, ensuring efficient and stable operation in complex traffic environments. This in turn improves vehicle recognition accuracy and response speed, better adapting to the needs of modern traffic management.

[0092] In one embodiment, see Figure 2 , also provides a control method for the above-mentioned multi-channel RSU antenna device, including steps S110~S140.

[0093] S110, the control unit 10 selects one of the multiple channels to send a BST wake-up signal, and sets the other channels to receive a return VST signal; S120, extracting the VST signal of each channel and parsing the signal to obtain the ID of the OBU, counting the number of parsing failures, and when the number exceeds a certain range, clearing the buffered data of the corresponding FIFO storage data buffer and resending the BST wake-up signal; wherein, a FIFO storage data buffer is allocated for each channel; S130, after successful analysis, pre-process the current channel number, OBU ID and signal RSSI value, and store the analyzed content in the FIFO storage data buffer; S140, compare the FIFO storage data buffer of each channel, and if the set requirements are met, it is determined that a link binding relationship is established between the current channel and the OBU ID, and the OBU to be traded is locked within the coverage area of the current channel, and the transaction identification or deduction process is continued; if the set requirements are not met, the OBU ID obtained by parsing is discarded, and the control unit 10 is re-executed to select one of the multiple channels to send a BST wake-up signal, and set other channels to receive the return VST signal.

[0094] It should be noted that technical personnel in the relevant field can clearly understand that the specific implementation process of the control method of the above-mentioned multi-channel RSU antenna device can refer to the corresponding description in the aforementioned device embodiment. For the convenience and conciseness of the description, it will not be repeated here.

[0095] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A multi-channel RSU antenna device, characterized in that: include: A control unit and a plurality of RSU antenna units, wherein each of the RSU antenna units constitutes a channel; The control unit is connected to a plurality of the RSU antenna units via a control bus.

2. A multi-channel RSU antenna device according to claim 1, characterized in that: Each of the RSU antenna units includes a radio frequency transceiver, a downlink signal amplifier, an uplink signal amplifier, a bandpass filter and a directional antenna; the radio frequency transceiver is connected to the control unit; the radio frequency transceiver is connected to the downlink signal amplifier; the directional antenna is connected to the bandpass filter; the bandpass filter is connected to the uplink signal amplifier; the uplink signal amplifier is connected to the radio frequency transceiver; and the downlink signal amplifier is connected to the directional antenna.

3. The multi-channel RSU antenna device according to claim 1, characterized in that: The directional antennas in the multiple RSU antenna units include circularly polarized array antennas with different coverage directions.

4. A multi-channel RSU antenna device according to any one of claims 1 to 3, characterized in that: There are four channels, and the four channels correspond to the four directions of the intersection respectively.

5. The multi-channel RSU antenna device according to claim 2, characterized in that: The radio frequency transceiver includes a 5.8G transceiver chip integrated with a radio frequency transceiver front end.

6. The multi-channel RSU antenna device according to claim 1, characterized in that: It also includes a PSAM card security encryption and decryption module; the PSAM card security encryption and decryption module is connected to the control unit.

7. The multi-channel RSU antenna device according to claim 1, characterized in that: It also includes a multi-channel radio frequency over-current detection module, which is connected to the control unit.

8. The multi-channel RSU antenna device according to claim 1, characterized in that: It also includes a downlink output power detection module; the downlink output power detection module is connected to the control unit.

9. The multi-channel RSU antenna device according to claim 1, characterized in that: It also includes a multi-channel radio frequency temperature detection module; the multi-channel radio frequency temperature detection module is connected to the control unit.

10. A control method for a multi-channel RSU antenna device according to any one of claims 1 to 9, characterized in that: include: The control unit selects one of the multiple channels to send a BST wake-up signal and sets the other channels to receive the return VST signal; Extract the VST signal of each channel and parse the signal to obtain the ID of the OBU, count the number of parsing failures, and when the number exceeds a certain range, clear the buffered data of the corresponding FIFO storage data buffer and resend the BST wake-up signal; wherein, a FIFO storage data buffer is allocated for each channel; After successful parsing, the current channel number, OBU ID and signal RSSI value are preprocessed and the parsed content is stored in the FIFO storage data buffer; The FIFO storage data buffers of each channel are compared. If the set requirements are met, the current channel is determined to establish a link binding relationship with the OBU ID, the OBU to be traded is locked within the coverage area of the current channel, and the transaction identification or deduction process is continued; if the set requirements are not met, the OBU ID obtained by parsing is discarded, and the control unit is re-executed to select one of the multiple channels to send a BST wake-up signal, and set other channels to receive the return VST signal.

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