Vehicle-mounted satellite communication terminal system and switching method

Abstract

The invention relates to the field of vehicle-mounted wireless communication, and provides an implementation scheme of an intelligent vehicle-mounted satellite communication terminal system, which comprises an MCU (Microprogrammed Control Unit) and a 5Gamp, the method comprises the following steps of: firstly, carrying out a global navigation satellite system (GNSS) Module, a satellite Module, a wireless fidelity (WIFI) Module, a Bluetooth low energy (BLE) Module and the like. All antennas are integrated in the vehicle-mounted satellite communication terminal, and through the ingenious design, the performance is improved, and antenna connectors and external antennas are saved, so that the cost is reduced. Especially, the GNSS antenna and the Tiantong / low-orbit satellite communication antenna adopt a common design, so that a double-layer ceramic antenna is saved, the cost is reduced, and the problem that the arrangement position of the satellite antenna is difficult to find is solved.

Description

Technical Field

[0001] This invention relates to the technical field of vehicle-mounted wireless communication, and specifically to a vehicle-mounted satellite communication terminal system and switching method. Background Technology

[0002] With the development of the Internet of Vehicles (IoV), terrestrial mobile communication systems (5G, 4G, 3G, 2G) can no longer meet users' communication needs anytime, anywhere. As satellite communication technology becomes increasingly prevalent in mobile terminals, more and more OEMs are integrating satellite communication functionality into in-vehicle wireless communication terminals to compensate for blind spots in terrestrial cellular communication and provide emergency communication for users. The increase in the number of normal communication antennas not only increases cost pressures but also increases the difficulty of deployment due to the different environmental requirements of different antennas. GNSSANT and SatelliteANT are both directional antennas, requiring their maximum radiating surface to face the sky without obstructions, making deployment difficult. Separate antenna solutions are too expensive and disadvantageous to market competitiveness. Summary of the Invention

[0003] This invention aims to reduce costs and deployment difficulty without affecting communication performance.

[0004] This invention provides a vehicle-mounted satellite communication terminal system, characterized in that it includes:

[0005] Four 5G antennas surround the communication module. ANT1 / ANT3 are linearly polarized antennas designed according to the right-hand screw law, while ANT2 / ANT4 are linearly polarized antennas designed according to the left-hand screw law. The polarizations of adjacent antennas are orthogonal.

[0006] WiFi / BLE system: WiFiANT1 uses an IFA antenna, WiFiANT2 uses a monopole antenna, and the BLE antenna and WiFi antenna are placed at opposite ends of the PCB.

[0007] RKE / TPMS antenna: Dual-band common of 315MHz / 433.93MHz, radiator is a left- or right-handed composite antenna;

[0008] Satellite antenna: Dual-layer ceramic antenna, including dual-frequency GNSSRHCP and Tiantong satellite LHCP, supporting manual / automatic trigger mode switching.

[0009] Furthermore, in the 5G antenna, ANT1 / ANT3 covers 703-960MHz.

[0010] 1700-5000MHz, ANT2 / ANT4 covers 1700-5000MHz, and the orthogonal polarization arrangement provides an isolation of >25dB.

[0011] Furthermore, the Satellite antenna's ability to trigger an E-call in the absence of a cellular network includes: acceleration > 5G, tilt angle > 60°, or abnormal heart rate.

[0012] Furthermore, the radiator of the RKE / TPMS antenna is a ring structure, with one side disconnected and loaded with an LC notch filter to suppress 5G band harmonic interference >20dB.

[0013] A switching method for a vehicle-mounted satellite communication terminal system, applied to the above system, includes the following steps:

[0014] Monitor manual and automatic trigger signals;

[0015] Interrupt GNSS positioning and save latitude, longitude, altitude, and timestamp to non-volatile memory;

[0016] Switch the bridge phase and reconstruct the RF link;

[0017] Establish satellite communication and report vehicle status parameters within 500ms.

[0018] Furthermore, the dual-layer ceramic antenna includes:

[0019] The upper square ceramic substrate integrates the GNSSL1 band 1559-1602MHz and the Tiantong Rx band 2170-2200MHz. The upper left corner of the inner ring of the radiating body realizes LHCP, and the upper right corner of the outer ring realizes RHCP. The inner ring is coupled to the outer ring through a gap for power feeding.

[0020] The lower square ceramic substrate integrates the GNSSL5 band 1164-1214MHz and the TianTong Tx band 1980-2010MHz, with a polarization chamfer design that is mirror-symmetrical to the upper layer;

[0021] Four feeding pins Pin1-Pin4, wherein Pin1 and Pin2 penetrate the lower layer and connect to the upper radiator, and Pin3 and Pin4 connect to the lower radiator;

[0022] The dynamic reconfiguration circuit includes a frequency band adjustable variable bridge and three RF switches for switching between GNSS and Tiantong modes.

[0023] Furthermore, the dual-layer ceramic antenna includes:

[0024] The upper circular ceramic substrate integrates the GNSSL1 band and the Tiantong Rx band. The phase difference between the feed points Pin1 / Pin2 is controlled by the first 3dB bridge group to achieve RHCP or LHCP polarization switching.

[0025] The lower circular ceramic substrate integrates the GNSSL5 band and the Tiantong Tx band. The phase difference between the feed points Pin3 / Pin4 is controlled by the second 3dB bridge group to achieve RHCP or LHCP polarization switching.

[0026] The dynamic reconfiguration circuit includes four RF switches (S1-S4) and four 3dB bridges for switching between GNSS and Tiantong modes.

[0027] Furthermore, the phase difference control of the dual-layer ceramic antenna satisfies:

[0028] In GNSS mode: Ph_pin2 = Ph_pin1 - 90°, upper RHCP; Ph_pin3 = Ph_pin4 - 90°, lower RHCP;

[0029] In TianTong mode: Ph_pin1 = Ph_pin2 - 90°, upper layer LHCP; Ph_pin3 = Ph_pin4 - 90°, lower layer LHCP.

[0030] This invention integrates all antennas within the vehicle-mounted satellite communication terminal. This ingenious design not only improves performance but also eliminates the need for antenna connectors and external antennas, thereby reducing costs. In particular, the GNSS antenna and the Tiantong / Low Orbit satellite communication antenna utilize a shared design, which not only saves on a double-layer ceramic antenna, reducing costs, but also solves the problem of finding suitable locations for satellite antenna placement. Attached Figure Description

[0031] Figure 1 This is a system block diagram of a preferred embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of another preferred embodiment of the present invention;

[0033] Figure 3 This is a flowchart of an antenna switching method according to another preferred embodiment of the present invention;

[0034] Figure 4 A side view of the Satellite antenna, which is a double-layer square ceramic antenna, according to another preferred embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the GNSS working state structure according to another preferred embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the antenna transmission state structure according to another preferred embodiment of the present invention.

[0037] Figure 7 This is a schematic diagram of the antenna receiving state structure according to a preferred embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of a double-layer circular ceramic antenna structure for the Satellite antenna, which is another preferred embodiment of the present invention. Detailed Implementation

[0039] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0040] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0041] The technical solution of this invention adopts an integrated design of S-BOX (satellite communication box), T-BOX and antenna box. Through ingenious antenna design, it not only reduces costs, but also overcomes the problems of strict installation requirements and difficult location of traditional vehicle communication terminals.

[0042] The system block diagram of this solution is as follows: Figure 1 As shown, it includes:

[0043] Modem communication module: Supports 5G NR Sub 6G, FDD-LTE, TDD-LTE

[0044] Multiple standards including WCDMA and GSM; handles communication routing, switching, and ITS protocol;

[0045] MCU: Body Processor, which handles vehicle information exchange;

[0046] SatelliteModule: Supports in-vehicle satellite calls and satellite SMS;

[0047] GNSS: Supports GNSSL1+L5 multi-frequency satellite positioning system, and supports independent BeiDou positioning;

[0048] EMMC: Automotive grade, supports big data collection;

[0049] Ethernet: Supports one 1000base-T1 communication channel;

[0050] CAN transceiver: automotive grade, supports 1-channel CANFD;

[0051] IMU: 6-axis sensor, supporting inertial navigation, collision and rollover detection.

[0052] Backup battery: Supports business operation after external power supply failure;

[0053] Supports ECALL and BCALL services;

[0054] Hardware layout as follows Figure 2 As shown, the present invention adopts an integrated design scheme that combines the S-BOX (satellite communication box), T-BOX, and antenna box.

[0055] Figure 2 This is a hardware layout diagram.

[0056] Built-in antennas: 5GANT1, 5GANT2, 5GANT3, 5GANT4, BLEANT, RKEANT, SatelliteANT (shared with GNSS antenna and Tiantong / Low Orbit satellite antenna)

[0057] External antennas: V2X-1ANT and V2X-2ANT are connected to the external antennas via FAKRA connectors.

[0058] The antenna configuration is shown in Table 1.

[0059]

[0060] 1) 5G cellular antenna description:

[0061] Four 5G antennas are arranged around the distributed communication module, ensuring that the loss of the four channels is within 3dB, thereby effectively improving the system throughput. Adjacent antennas adopt different design principles, which solves the problem of decoupling between the four antennas.

[0062] 5GANT1 and 5GANT3 are two full-band antennas, designed with a right-handed antenna and conforming to the right-hand screw law.

[0063] 5GANT2 and 5GANT3 are two mid-to-high frequency antennas, which adopt a left-handed antenna design and conform to the left-handed spiral law.

[0064] 2) Explanation of WIFI and BLE antennas:

[0065] WIFIANT1 uses an IFA antenna and WIFIANT2 uses a monopole antenna, which improves the isolation between the two antennas. After solving the isolation problem, WIFIANT1 and WIFIANT2 can be arranged around the WIFI module, which optimizes the RF routing, reduces path loss, and thus improves the performance of the WIFI system.

[0066] The BLE antenna and the WIFI antenna are located at opposite ends of the PCB board, achieving spatial isolation by increasing the distance between them.

[0067] 3) REK antenna description:

[0068] The RKE (Remote Keyless Entry) and TPMS (Tire Pressure Monitoring System) share a single antenna, operating at frequencies of 315MHz or 433.93MHz. They employ a left- or right-handed antenna design, which effectively reduces the impact on other antennas while minimizing antenna size.

[0069] 4) Satellite Antenna Description:

[0070] The dual-band GNSS antenna (RHCP) and the Tiantong / Low Orbit satellite antenna (LHCP) adopt a shared antenna design. By default, it operates in GNSS mode upon power-on. In the absence of a cellular network and upon successful E-call, it switches from GNSS to satellite communication mode. Figure 3 As shown

[0071] Mode 1: Manual trigger. The system defaults to GNSS positioning mode. When the user presses the emergency button, a trigger signal is generated, and the system controls the switch from GNSS to Tiantong / Low Orbit satellite communication mode.

[0072] Mode 2: Automatic triggering. The system defaults to GNSS positioning mode. When a vehicle collision occurs, the system receives sensor reports such as acceleration > 5G, tilt angle > 60°, and detects abnormal heart rate. It then generates a trigger signal and controls the system to switch from GNSS to Tiantong / Low Orbit satellite communication mode.

[0073] Antenna design: such as Figure 4 As shown, the Satellite antenna uses a double-layer square ceramic antenna.

[0074] Upper ceramic L1 GNSS (1559-1602MHz) + Tiantong Rx (2170-2200MHz): Pins 1 and 2 are the feed points for the upper antenna, passing through the lower ceramic layer and connecting to the radiating surface of the upper ceramic layer. The upper left chamfer of the inner radiator achieves LHCP, serving as the Tiantong RX antenna. The inner radiator is coupled to the outer radiator through a slot for power feeding, and together with the upper right chamfer of the outer radiator, it achieves an RHCP antenna that meets GNSS L1 requirements.

[0075] Lower layer: GNSS (1164-1214MHz) + Tiantong Tx (1980-2010MHz): Pins 3 and 4 are the feed points for the lower layer antenna, connected to the radiating surface of the lower layer ceramic. The upper left chamfer of the inner ring radiator achieves LHCP, serving as the Tiantong TX antenna. The inner ring radiator is coupled to the outer ring radiator through a slot for feeding, and together with the upper right chamfer of the outer ring radiator, it achieves the RHCP antenna that meets GNSSL5 requirements.

[0076] GNSS operating status: such as Figure 5As shown, under default conditions, the system controls variable bridge 1 to operate in the L1 frequency band, variable bridge 2 to operate in the L5 frequency band, and switches S1 and S2 to switch to the GNSS path to realize the GNSS positioning function.

[0077] Switching process: GNSS → Tiantong mode

[0078] Upon receiving the switching command, the system controls variable bridge 1 to operate in the Tiantong TX band, variable bridge 2 to operate in the Tiantong RX band, switch S1 to switch to the Tiantong TX path, and switch S2 to switch to the Tiantong RX path.

[0079] Switch S3 is divided into TX and RX states. Tiantong uses time division multiplexing, and the system controls S3 to synchronize with the transmit and receive states of the transceiver in the satellite module. Figure 6 In Tiantong launch status,

[0080] Figure 7 TianTong receiving status:

[0081] 0-10ms: The system interrupts GNSS signal processing, and the positioning data is saved locally.

[0082] 10-50ms: The system control switch switches to the Tiantong channel and controls the variable bridge to work in the Tiantong frequency band.

[0083] 50-200ms: RF link reconfiguration, network registration completed.

[0084] 200-500ms: Satellite communication link established, and location information reported via SMS.

[0085] Antenna design: such as Figure 8 As shown, the Satellite antenna uses a double-layer circular ceramic antenna.

[0086] Upper ceramic L1GNSS (1559-1602MHz) + Tiantong Rx (2170-2200MHz): pin1 and pin2 are the feed points of the upper antenna, passing through the lower ceramic layer and connecting to the radiating surface of the upper ceramic layer. The inner radiator is the Tiantong RX antenna. The signal is passed through a 3dB bridge to make the phase of the signal at feed point pin2 lag the phase of the signal at feed point pin1 by 90° (i.e., Ph_pin2 = Ph_pin1 - 90°), thus achieving right-hand circular polarization (RHCP).

[0087] The inner radiator is coupled to the outer radiator through a gap to form a GNSS L1 antenna. The signal passes through a 3dB bridge to make the phase of the signal at feed point pin1 lag behind the phase of the signal at feed point pin2 by 90° (i.e., Ph_pin1 = Ph_pin2 - 90°), thus achieving left-hand circular polarization (LHCP).

[0088] Lower layer: GNSS L5 (1164-1214MHz) + Tiantong Tx (1980-2010MHz): pin3 and pin4 are the feed points of the lower layer antenna, connected to the radiating surface of the lower layer ceramic, forming the Tiantong TX antenna. A 3dB bridge is used to lag the signal phase of feed point pin4 by 90° compared to the signal phase of feed point pin3 (i.e., Ph_pin4 = Ph_pin3 - 90°) to achieve left-hand circularly polarized (LHCP).

[0089] The inner radiator is coupled to the outer radiator through a gap to form a GNSS L5 antenna. The signal phase of the feed point Pin3 is delayed by 90° from the signal phase of the feed point Pin4 (i.e., Ph_pin3 = Ph_pin4 - 90°) by a 3dB bridge to achieve right-hand circular polarization (RHCP).

[0090] GNSS operating status: In the default state, the system controls S1 and S2 switch to 3dB bridge 2, so that the signal phase of feed point pin2 lags behind the signal phase of feed point pin1 by 90° (i.e., Ph_pin2=Ph_pin1-90°), and the upper antenna achieves right-hand circular polarization (RHCP). At this time, the path is in GNSSL1 receiving state.

[0091] The system controls S3 and S4 to switch to 3dB bridge 4, so that the signal phase of feed point pin3 lags behind the signal phase of feed point pin4 by 90° (i.e., Ph_pin3 = Ph_pin4 - 90°), and the lower antenna achieves right-hand circular polarization (RHCP). At this time, the path is in GNSSL5 receiving state.

[0092] Switching process: GNSS → Tiantong mode

[0093] Upon receiving the switching command, the system controls S1 and S2 to switch to 3dB bridge 1, causing the signal phase of feed point pin1 to lag behind the signal phase of feed point pin2 by 90° (i.e., Ph_pin1 = Ph_pin2 - 90°), and the upper antenna achieves left-hand circular polarization (LHCP), at which point it is in the Tiantong transmission state.

[0094] The system controls S3 and S4 to switch to 3dB bridge 3, so that the signal phase of feed point pin3 lags behind the signal phase of feed point pin4 by 90° (i.e., Ph_pin3 = Ph_pin4 - 90°). The lower antenna achieves left-hand circular polarization (LHCP), and at this time it is in the antenna reception state.

[0095] 0-10ms: The system interrupts GNSS signal processing, and the positioning data is saved locally.

[0096] 10-50ms: The system control switch switches to the Tiantong channel.

[0097] 50-200ms: RF link reconfiguration, network registration completed.

[0098] 200-500ms: Satellite communication link established, and location information reported via SMS.

[0099] This invention integrates all antennas within the vehicle-mounted satellite communication terminal, eliminating the need for antenna connectors and external antennas, thereby reducing costs. The use of both GNSS and Satellite antennas eliminates the need for a double-layer ceramic antenna, further reducing costs. The GNSS and Satellite antennas also reduce the overall size of the device, facilitating vehicle placement. The hardware solution of this invention is based on a mature platform, ensuring reliability, simplicity, and low cost.

[0100] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A vehicle-mounted satellite communication terminal system, characterized in that, include: Four 5G antennas surround the communication module. ANT1 / ANT3 are linearly polarized antennas designed according to the right-hand screw law, while ANT2 / ANT4 are linearly polarized antennas designed according to the left-hand screw law. The polarizations of adjacent antennas are orthogonal. WiFi / BLE system: WiFiANT1 uses an IFA antenna, WiFiANT2 uses a monopole antenna, and the BLE antenna and WiFi antenna are placed at opposite ends of the PCB. RKE / TPMS antenna: Dual-band common of 315MHz / 433.93MHz, radiator is a left- or right-handed composite antenna; Satellite antenna: Dual-layer ceramic antenna, including dual-frequency GNSSRHCP and Tiantong satellite LHCP, supporting manual / automatic trigger mode switching.

2. The system according to claim 1, characterized in that, In the 5G antenna, ANT1 / ANT3 covers 703-960MHz. 1700-5000MHz, ANT2 / ANT4 covers 1700-5000MHz, and the orthogonal polarization arrangement provides an isolation of >25dB.

3. The system according to claim 1, characterized in that, The Satellite antenna is used in situations where there is no cellular network and an E-call is triggered, including: acceleration > 5G, tilt angle > 60°, or abnormal heart rate.

4. The system according to claim 1, characterized in that, The radiator of the RKE / TPMS antenna is a ring structure, with one side disconnected and loaded with an LC notch filter to suppress 5G band harmonic interference >20dB.

5. A switching method for a vehicle-mounted satellite communication terminal system, applied to the system described in any one of claims 1-4, comprising the steps of: Monitor manual and automatic trigger signals; Interrupt GNSS positioning, save latitude, longitude, altitude, and timestamp to non-volatile memory; switch bridge phase, reconstruct radio frequency link; Establish satellite communication and report vehicle status parameters within 500ms.

6. The system according to claim 1, characterized in that, The dual-layer ceramic antenna includes: The upper square ceramic substrate integrates the GNSSL1 band 1559-1602MHz and the Tiantong Rx band 2170-2200MHz. The upper left corner of the inner ring of the radiating body realizes LHCP, and the upper right corner of the outer ring realizes RHCP. The inner ring is coupled to the outer ring through a gap for power feeding. The lower square ceramic substrate integrates the GNSSL5 band 1164-1214MHz and the TianTong Tx band 1980-2010MHz, with a polarization chamfer design that is mirror-symmetrical to the upper layer; Four feeding pins Pin1-Pin4, wherein Pin1 and Pin2 penetrate the lower layer and connect to the upper radiator, and Pin3 and Pin4 connect to the lower radiator; The dynamic reconfiguration circuit includes a frequency band adjustable variable bridge and three RF switches for switching between GNSS and Tiantong modes.

7. The system according to claim 1, characterized in that, The dual-layer ceramic antenna includes: The upper circular ceramic substrate integrates the GNSSL1 band and the Tiantong Rx band. The phase difference between the feed points Pin1 / Pin2 is controlled by the first 3dB bridge group to achieve RHCP or LHCP polarization switching. The lower circular ceramic substrate integrates the GNSSL5 band and the Tiantong Tx band. The phase difference between the feed points Pin3 / Pin4 is controlled by the second 3dB bridge group to achieve RHCP or LHCP polarization switching. The dynamic reconfiguration circuit includes four RF switches (S1-S4) and four 3dB bridges for switching between GNSS and Tiantong modes.

8. The system according to claim 7, characterized in that, The phase difference control of the dual-layer ceramic antenna satisfies: In GNSS mode: Ph_pin2 = Ph_pin1 - 90°, upper RHCP; Ph_pin3 = Ph_pin4 - 90°, lower RHCP; In TianTong mode: Ph_pin1 = Ph_pin2 - 90°, upper layer LHCP; Ph_pin3 = Ph_pin4 - 90°, lower layer LHCP.

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