Communication circuit with positioning function

Abstract

The utility model discloses a communication circuit with a positioning function, which overcomes the problem of high cost of independently realizing a GPS (Global Positioning System) function and a communication function in the prior art, and comprises a GPS circuit, the GPS circuit is connected with a communication MCU (Microprogrammed Control Unit) through a level conversion circuit, the GPS circuit is connected with a GPS antenna, the communication MCU is connected with a power supply manager, and the communication MCU is connected with a signal transmission circuit. The GPS positioning function is integrated into the communication circuit, the communication MCU and the power manager in the communication circuit are shared, the cost is reduced, the GPS signal strength is not affected, the integration degree is high, and the production and installation efficiency is high.

Description

Technical Field

[0001] The utility model relates to the technical field of GPS positioning, in particular to a communication circuit with a positioning function. Background Art

[0002] Through communication circuits, information can be transmitted in the form of electricity, light, wireless, etc., thus realizing remote communication and information transmission between people. In the remote data communication of the power industry, the mobile communication network (2G3G4G) is used alone for communication, which has functions such as transparent data forwarding and remote upgrade, and can load or delete related configurations as needed. However, the existing communication module only supports 2G / 3G / 4G mobile communication networks, and its application in the electric meter industry has its limitations. For example, if on-site meter reading or maintenance is required, for some industrial meters in industrial areas or civil meters in remote areas, the staff are not familiar with the geographical location of the electricity consumption site and cannot quickly and accurately locate the user's electricity consumption site.

[0003] Although adding GPS function to the meter can achieve positioning, if the GPS module is added to the meter alone, the overall cost will increase significantly, and an extra position for plugging in the module will be required at the meter end. If the GPS module is made built-in and installed inside the meter case, it will also affect the signal strength of the GPS module. Summary of the invention

[0004] The purpose of the utility model is to overcome the problems in the prior art of high cost of separately installing a GPS module in a meter and poor signal strength of a built-in GPS module in the meter, and to provide a communication circuit with a positioning function, integrating the GPS positioning function into the communication circuit, thereby reducing costs while not affecting the GPS signal strength, having a high degree of integration and high production and installation efficiency.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A communication circuit with a positioning function comprises a GPS circuit, wherein the GPS circuit is connected to a communication MCU via a level conversion circuit, the GPS circuit is connected to a GPS antenna, the communication MCU is connected to a power manager, and the communication MCU is connected to a signal transmission circuit.

[0007] By adding a GPS circuit to the communication circuit, the communication circuit has a positioning function. At the same time, the added GPS circuit does not require an additional MCU and power supply circuit, and directly shares its internal communication MCU and power manager with the original communication circuit. The power manager is connected to a battery or an external power supply, which reduces costs while not affecting the GPS signal strength. It has a high degree of integration and high production and installation efficiency.

[0008] Preferably, the GPS circuit comprises a SAW filter connected to the GPS antenna, the SAW filter is connected to a GPS positioning chip, and the GPS positioning chip is connected to the communication MCU.

[0009] Preferably, the signal transmission circuit includes a radio frequency front end connected to the communication MCU, and the radio frequency front end is connected to a radio frequency antenna.

[0010] Preferably, the communication MCU includes a memory and a radio frequency transceiver connected to a signal transmission circuit.

[0011] Preferably, a crystal oscillator connected to the communication MCU is also included.

[0012] Preferably, the level conversion circuit includes a first transistor and a second transistor, the collector of the first transistor is connected to the GPS circuit, the collector of the second transistor is connected to the GPS circuit, the base of the first transistor is connected to the base of the second transistor, the emitter of the first transistor is connected to the communication MCU, and the emitter of the second transistor is connected to the communication MCU.

[0013] Preferably, the communication circuit includes a digital interface unit connected to the communication MCU.

[0014] Preferably, the memory includes a pseudo-static random access memory and a non-volatile flash memory.

[0015] Preferably, the digital interface unit includes a USIM interface and a USB interface.

[0016] Therefore, the utility model has the following beneficial effects:

[0017] Adding GPS positioning function to the original mobile communication circuit can greatly reduce costs, improve the degree of design integration, and facilitate the efficiency of subsequent production and installation. At the same time, it can enable smart meters or concentrators equipped with this communication circuit to have positioning functions, and the GPS signal strength will not be affected, so it can be quickly and accurately positioned. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall architecture of the communication circuit in the utility model.

[0019] Figure 2 It is a schematic diagram of the overall architecture of the GPS circuit in the utility model.

[0020] Figure 3 It is a circuit structure diagram of the GPS positioning chip in the utility model.

[0021] Figure 4 The utility model is a schematic diagram of the circuit structure of the peripheral circuit of the GPS positioning chip.

[0022] Figure 5 It is a circuit structure diagram of the SAW filter in the utility model.

[0023] Figure 6 It is a circuit structure schematic diagram of the level conversion circuit in the utility model.

[0024] In the figure: 1. GPS circuit; 2. Communication circuit; 3. GPS antenna; 4. RF antenna; 5. Power manager; 6. Communication MCU; 7. RF front end; 8. RF transceiver; 9. Baseband; 10. Memory; 11. Crystal oscillator; 12. Digital interface circuit; 13. GPS antenna power supply; 14. SAW filter; 15. GPS positioning chip; 16. Terminal. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods:

[0026] Embodiment 1:

[0027] This embodiment is a communication circuit with a positioning function, and its overall structure is as follows Figure 1 As shown, the communication circuit 2 includes a GPS circuit 1, a communication MCU 6, a power manager 5, a signal transmission circuit and a GPS antenna 3. The GPS circuit is connected to the GPS antenna and the communication MCU respectively, and the communication MCU is connected to the signal transmission circuit for wireless communication; the communication MCU is connected to the power manager, and the power manager is connected to a battery or an external power supply to power the communication circuit.

[0028] The communication circuit with positioning function provided in this embodiment can significantly reduce costs, improve the degree of design integration, and facilitate the efficiency of subsequent production and installation. At the same time, it can enable smart meters or concentrators equipped with this communication circuit to have positioning functions, and the GPS signal strength will not be affected, so that positioning can be achieved quickly and accurately.

[0029] Specific:

[0030] The GPS circuit includes a SAW filter 14 and a GPS positioning chip 15 . The SAW filter is connected to the GPS antenna. The SAW filter is connected to the GPS positioning chip. The GPS positioning chip is connected to the communication MCU.

[0031] like Figure 2As shown, the working power of the GPS antenna is provided by the GPS antenna power supply 13. When the GPS circuit is working, the GPS antenna receives the GPS signal and transmits the received GPS signal to the SAW filter to filter out the signal, noise and spurious signal in the non-GPS frequency band of the GPS signal. Then the SAW filter sends the filtered GPS signal to the GPS positioning chip, the GPS positioning chip performs positioning calculation, and the positioning result is sent to the terminal 16.

[0032] In this embodiment, the SAW filter adopts the filter model DNI-SFDG89JA402; the GPS positioning chip adopts the chip model AT6558D-5N32; and the communication MCU adopts the chip model UIS8910DM.

[0033] The signal transmission circuit includes a radio frequency front end 7 and a radio frequency antenna 4, wherein the radio frequency front end is connected to a radio frequency transceiver in the communication MCU, and the radio frequency front end is also connected to the radio frequency antenna.

[0034] The RF front-end (RF Front-End) refers to the circuits and modules that connect the communication MCU and the RF antenna. It is responsible for converting digital signals into wireless signals suitable for transmission and providing necessary amplification, filtering, modulation and other functions.

[0035] In this embodiment, the radio frequency front end includes:

[0036] 1. Transceiver: The transceiver is the core component of the RF front end. It is responsible for converting digital signals into wireless signals and converting received wireless signals into digital signals. The transceiver usually includes modules such as RF amplifier, mixer, local oscillator, etc., which are used to convert and adjust the frequency.

[0037] 2. Filter: Filters play a key role in the RF front end, used to remove unwanted frequency components and retain the required signals. Common filters include bandpass filters, low-pass filters, and high-pass filters to adapt to different wireless communication frequency bands and signal requirements.

[0038] 3. Power Amplifier: The power amplifier is an important component of the RF front end, used to enhance the power of the transmitted signal so that it can achieve long-distance coverage during the transmission process. The design of the power amplifier needs to consider factors such as power efficiency, linearity and temperature stability.

[0039] The power manager can be connected to a battery and can also receive a reset signal; the power manager is connected to an analog-to-digital converter ADC, and the analog-to-digital converter converts an analog signal into a digital signal and sends it to the power manager.

[0040] The communication MCU includes a radio frequency transceiver 8, a baseband 9 and a memory 10, wherein the memory includes a 64Mb non-volatile flash memory (NOR flash) and a 128Mb pseudo static random access memory (PSRAM).

[0041] In this embodiment, the signal transmission circuit further includes a digital interface unit 12 and a crystal oscillator 11 (a 26 MHz crystal oscillator is selected in this embodiment), and both the digital interface unit and the crystal oscillator are connected to the communication MCU.

[0042] The digital interfaces include USIM interface, I2C interface, SPI interface, KEYPAD interface, UART interface and USB interface. The communication circuit is connected to USIM (SIM mobile communication card) through the USIM interface; the communication circuit is connected to the PC through the USB interface.

[0043] The crystal oscillator has the following functions:

[0044] 1. Provide accurate clock signals: Communication circuits require accurate clock signals to coordinate the work of various components, such as modulation and demodulation, data transmission, channel control, etc. Crystal oscillators can provide high-precision clock signals to ensure stable and reliable operation of communication circuits.

[0045] 2. Improve data transmission rate: The crystal oscillator can be used for data transmission to improve the data transmission rate. In the cellular communication circuit of this embodiment, the crystal oscillator is used to modulate and demodulate the signal to improve the stability and reliability of data transmission.

[0046] 3. Noise filtering: The crystal oscillator can filter out noise in the circuit and improve the performance of the communication device. In the communication circuit of this embodiment, the crystal oscillator can filter out radio frequency noise and improve sensitivity and anti-interference ability.

[0047] The communication circuit with positioning function provided in this embodiment can solve the following problems:

[0048] 1. If the GPS function and module communication function are implemented separately, the cost will be much higher.

[0049] 2. In many scenarios, it is inconvenient to find the installation location of the on-site electricity meter.

[0050] 3. The distribution and specific location of the electricity meters cannot be intuitively seen in the background.

[0051] The following beneficial effects can be achieved:

[0052] Integrating GPS functions into communication circuits can reduce the cost of implementing both functions at the same time and facilitate maintenance and installation.

[0053] Embodiment 2:

[0054] This embodiment provides a communication circuit with a positioning function, and further optimizes the solution of Embodiment 1 in combination with specific application scenarios and specific circuit structures.

[0055] Smart meters are one of the basic devices for data collection in smart grids (especially smart distribution networks). They are responsible for collecting, measuring and transmitting raw power data, and are the basis for information integration, analysis optimization and information display. Smart meters use mobile communication networks (2G3G4G) to communicate, and can realize transparent data forwarding, remote upgrades and other functions, and can load or delete related configurations as needed. If on-site meter reading or meter maintenance is required, some industrial meters in industrial areas or civil meters in remote areas, the staff are not familiar with the geographical location of the power consumption site, and cannot quickly and accurately locate the user's power consumption site. Although adding GPS function to smart meters can achieve positioning, the location and distribution of meters installed in certain areas can be seen in real time through software or large screens in the later stage, which is simple and intuitive. However, adding a GPS module to the meter alone will increase the cost, and if the GPS module is built into the case, the signal strength of the GPS will be affected.

[0056] The communication circuit provided by this embodiment can realize the communication and positioning functions of the electric meter and save costs. The GPS positioning function is added to the original mobile communication circuit, so that the smart electric meter equipped with this communication circuit has the positioning function, which can quickly and accurately locate the power consumption site, and quickly and accurately locate the fault point for user fault repair work; at the same time, compared with the independent design of the GPS module, integrating the GPS function module into the mobile communication circuit can greatly reduce the cost, improve the integration of the design, and facilitate the efficiency of subsequent production and installation.

[0057] The communication circuit includes a GPS circuit, the GPS circuit is connected to the communication MCU and the GPS antenna, the communication MCU is connected to the power manager, and the communication MCU is connected to the communication circuit.

[0058] The overall architecture of GPS circuit is as follows Figure 2 As shown, the specific workflow is:

[0059] (1) Signal reception and filtering: The communication circuit has added a GPS function, and a GPS active antenna needs to be matched to the external circuit of the communication circuit to receive the satellite positioning information. After the GPS antenna receives the GPS signal, it filters out the signals, noise and spurious signals in the non-GPS frequency band of the GPS signal through the SAW filter DNI-SFDG89JA402 inside the communication circuit.

[0060] (2) Signal sampling, demodulation and decoding: The SAW filter inputs the filtered GPS signal into the GPS positioning chip AT6558D-532, which samples, demodulates and decodes the GPS signal.

[0061] (3) Navigation data extraction: The GPS positioning chip extracts navigation data from the decoded signal, including the satellite's orbital parameters (ephemeris), time information, health status, etc.

[0062] (4) Pseudorange measurement and calculation: The GPS positioning chip calculates the pseudorange from the receiver to each satellite based on the time difference between each satellite signal reaching the receiver (determined by the phase difference of the pseudorandom code carried by the GPS signal). These pseudoranges include the true distance between the receiver and the satellite and the receiver clock error.

[0063] (5) Geometric position calculation: Using the pseudoranges of at least four satellites, the three-dimensional position (longitude, latitude, altitude) and precise time of the receiver are determined by solving a set of equations. Commonly used methods include the least squares method and Kalman filtering.

[0064] (6) Data output: Integrate the calculated position information, speed data and time information and output them to the user application or device in a standard format. For general GPS application software, a unified data format standard is required to solve the interface problem with any GPS.

[0065] This embodiment adopts the NMEA-0183 data standard (the NMEA protocol is to establish a unified RTCM standard in different GPS navigation devices). Through the NMEA-0183 protocol statement, the positioning information is transmitted to the power bureau's server or the handheld device of the relevant meter maintenance personnel through the mobile communication (2G3G4G) function of the communication circuit itself, so as to realize real-time viewing of relevant information on the location and distribution of the meter.

[0066] In summary, GPS positioning chips convert radio signals from satellites into precise location information through a series of complex signal processing steps. This involves radio frequency processing, digital signal processing and various mathematical calculations to provide reliable positioning services (the above calculations are all existing technologies).

[0067] After the GPS positioning function is realized through the GPS circuit, the GPS positioning information is transmitted through the level conversion circuit and the GPS_UART serial port of the communication MCU chip. At the same time, the RF signal is also connected through the interface circuit and the corresponding serial port of the communication MCU, so that all communication functions are integrated on a main chip, saving device costs and design costs, as well as the costs of subsequent processing and product installation and maintenance.

[0068] The specific structure of GPS circuit is as follows Figure 3 , Figure 4 as well as Figure 5 As shown, it includes SWA filter, GPS positioning chip and the peripheral circuit of GPS positioning chip. When the GPS circuit is working, the GPS signal GPS_ANT is received by the GPS antenna, filtered by SAW filter DNI-SFDG89JA402, and the filtered GPS signal is input to the GPS positioning chip AT6558D-5N32. After a series of processing such as sampling, demodulation and decoding, the positioning information is obtained.

[0069] The SWA filter circuit structure is as follows Figure 5 As shown, it includes a SWA filter FL700, a capacitor C700 and a capacitor C701, the INPUT end of the SWA filter FL700 is connected to one end of the capacitor C700 and one end of the capacitor C701, the other end of the capacitor C701 is grounded, and the other end of the capacitor C700 is connected to the GPS antenna; the OUTPUT end of the SWA filter FL700 is connected to the GPS positioning chip. Specifically, the OUTPUT end of the SWA filter FL700 is connected to the LAN_IN end of the GPS positioning chip, and an inductor L700 and a capacitor C703 are also provided between the LAN_IN end of the GPS positioning chip and the OUTPUT end of the SWA filter FL700.

[0070] The GPS signal processed by the GPS positioning chip AT6558D-5N32 is output to the communication MCU through the serial port GPS_TXD, but because the level of the GPS positioning chip and the communication MCU do not match, it cannot be transmitted correctly. Therefore, this embodiment designs a level conversion circuit to convert the level output by the GPS positioning chip and output a signal that can match the level of the communication MCU.

[0071] like Figure 6As shown, the level conversion circuit includes a transistor Q700, a transistor Q701, a resistor R701, a resistor R704, a resistor R703, a resistor R702, a capacitor C719 and a capacitor C720, wherein the collector of the transistor Q700 is connected to the GPS_RXD interface of the GPS positioning chip and the resistor R701, the emitter of the transistor Q700 is connected to the UART_G_TXD interface of the communication MCU, the base of the transistor Q700 is connected to one end of the resistor R702, and the other end of the resistor R702 is connected to the resistor One end of resistor R703 is connected to the V_IO18 interface, the other end of resistor R703 is connected to the base of transistor Q701, the emitter of transistor Q701 is connected to the GPS_TXD interface of the communication MCU, the collector of transistor Q701 is connected to one end of resistor R704, and the other end of resistor R704 is connected to one end of resistor R703; one end of resistor C719 is connected to the other end of resistor R704, and the other end of resistor C719 is grounded; one end of resistor C720 is connected to the other end of resistor R704, and the other end of resistor C720 is grounded.

[0072] The level signal output by the level conversion circuit receives the GPS positioning signal into the communication MCU through the URAT_G_RXD pin of the GPS_UART serial port. Similarly, the output signal URAT_G_TXD after processing by the communication MCU passes through the level conversion circuit to GPS_RXD and returns to the GPS positioning chip AT6558D-5N32, thus forming a complete set of communication serial ports.

[0073] Through this set of serial ports, the GPS signal is transmitted to the communication MCU, so the communication MCU can use the cellular communication function (2G / 3G / 4G) of the communication circuit itself to upload the obtained GPS information to the power bureau or other required terminals; thereby achieving the purpose of integrating the GPS positioning function into the cellular communication circuit, which not only meets the needs, but also does not require the addition of additional MCU and power supply circuit due to the increase of the positioning function, saving costs and improving the integration of the product.

[0074] The communication circuit with positioning function provided in this embodiment can realize the GPS positioning function, that is, integrate the GPS positioning function into the communication circuit of the smart meter, accurately locate the geographical location of the smart meter through the GPS circuit, and feed back the data information to the handheld mobile receiving terminal or the vehicle navigation system of the power staff through the mobile communication network, thereby determining the user's power consumption site, and providing the best path to the site, so as to improve the efficiency of inspection and emergency repair work. In other embodiments, the communication circuit with positioning function can also be used on terminals such as concentrators.

[0075] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A communication circuit with positioning function, characterized in that: It comprises a GPS circuit, wherein the GPS circuit is connected to a communication MCU via a level conversion circuit, the GPS circuit is connected to a GPS antenna, the communication MCU is connected to a power manager, and the communication MCU is connected to a signal transmission circuit.

2. A communication circuit with positioning function according to claim 1, characterized in that: The GPS circuit includes a SAW filter connected to a GPS antenna, the SAW filter is connected to a GPS positioning chip, and the GPS positioning chip is connected to a communication MCU.

3. A communication circuit with positioning function according to claim 1 or 2, characterized in that: The signal transmission circuit includes a radio frequency front end connected to the communication MCU, and the radio frequency front end is connected to a radio frequency antenna.

4. A communication circuit with positioning function according to claim 1 or 2, characterized in that: The communication MCU includes a memory and a radio frequency transceiver connected to a signal transmission circuit.

5. The communication circuit with positioning function according to claim 1, characterized in that: It also includes a crystal oscillator connected to the communication MCU.

6. A communication circuit with positioning function according to claim 1, 2 or 5, characterized in that: The level conversion circuit includes a first transistor and a second transistor, the first transistor collector is connected to the GPS circuit, the second transistor collector is connected to the GPS circuit, the first transistor base is connected to the second transistor base, the first transistor emitter is connected to the communication MCU, and the second transistor emitter is connected to the communication MCU.

7. A communication circuit with positioning function according to claim 1, 2 or 5, characterized in that: The signal transmission circuit includes a digital interface unit connected to the communication MCU.

8. The communication circuit with positioning function according to claim 4, characterized in that: The memory includes a pseudo-static random access memory and a non-volatile flash memory.

9. The communication circuit with positioning function according to claim 7, characterized in that: The digital interface unit includes a USIM interface and a USB interface.

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