A low-orbit narrow-band internet communication terminal supporting multi-device shared access

Abstract

The utility model discloses a kind of low orbit narrowband internet communication terminal of supporting multiple device sharing access, including terminal host computer and through guide integrated antenna.Terminal host computer is composed of low orbit narrowband communication module, main processor, ethernet module, wireless communication module, big dipper positioning module, radio frequency combining module and two-wire telephone module, support multiple user equipment through ethernet or WiFi simultaneously access, realize short message receiving and sending, voice interaction and network data transmission etc. Whole scene communication function.Radio frequency combining module is combined with direct current separation circuit through two levels, realize the combining of low orbit L frequency band radio frequency signal and big dipper positioning signal and antenna feed one-wire passage.This terminal has miniaturization, multiple user sharing, deployment flexibility etc. Characteristics, effectively reduce the multi-user access cost of low orbit satellite internet, improve equipment use efficiency.

Description

Technical Field

[0001] This utility model relates to the field of satellite communication technology, and in particular to a low-orbit narrowband Internet communication terminal with multi-user shared access. Background Technology

[0002] Low-Earth orbit (LEO) satellite internet, as an emerging communication infrastructure, features low latency, high speed, and wide coverage. It can be deployed more conveniently in areas without public network coverage, meeting the communication needs of fields such as the Internet of Things, commerce, emergency response, military, and deep-sea fishing. However, the current cost of LEO internet communication terminals is relatively high, and a single terminal can only meet the needs of a single user. Utility Model Content

[0003] In view of this, this application designs and implements a low-orbit narrowband internet communication terminal to address users' multi-access needs and miniaturized application scenarios. This terminal adopts a miniaturized design, is compact in size, supports full-scenario communication functions such as SMS sending and receiving, voice interaction, and network data transmission, supports simultaneous access by multiple user devices, realizes network sharing among multiple users, reduces the application cost of multi-user low-orbit interconnection, and improves the efficiency of terminal devices.

[0004] To achieve the above functions, the specific implementation scheme of this utility model is as follows: A low-orbit narrowband internet communication terminal that supports shared access by multiple devices includes a terminal host and an integrated communication and navigation antenna; the terminal host consists of a low-orbit narrowband communication module, a main processor, an Ethernet module, a wireless communication module, a Beidou positioning module, an RF combining module, and a two-line telephone module; The UART and PCM interfaces of the low-orbit narrowband communication module are connected to the corresponding interfaces of the main processor; the Beidou positioning module is connected to the main processor through the UART interface to realize Beidou positioning capability; the Ethernet module is connected to the main processor through the RMII interface to realize Ethernet communication capability; the wireless communication module is connected to the main processor through the USB interface to realize wireless WIFI access point capability; the two-line telephone module is connected to the main processor through the PCM signal interface, which is used to connect a telephone to realize local satellite telephone function. The RF L-transmit port of the low-orbit narrowband communication module is connected to the input terminal of the RF combiner module, and the RF L-receive port is connected to the output terminal of the RF combiner module; the RF combiner module is connected to the Beidou positioning module through the BDS port. The integrated communication and navigation antenna is connected to the radio frequency combining module via a radio frequency cable. Both ends of the radio frequency cable have TNC connectors to realize the reception, amplification and filtering of low-orbit narrowband L-frequency radio frequency transceiver and BeiDou positioning signals.

[0005] Furthermore, the RF combining module consists of a BeiDou RF filtering circuit, a DC blocking circuit, and a two-stage RF combining circuit. The input and output ports of the first-stage RF combining circuit are connected to the RF L transmitting port and RF L receiving port of the low-orbit narrowband communication module, respectively. The RF signal of the BeiDou RF filtering circuit and the BeiDou positioning module are connected by a 50Ω microstrip line on the board. The common terminal of the first-stage RF combining circuit and the input terminal of the BeiDou RF filtering circuit are connected to the branch ports of the second-stage RF combining circuit, respectively. The combining port of the second-stage RF combining circuit is connected to the integrated conduction antenna through the DC blocking circuit. The onboard RF cable between the DC blocking circuit and the integrated channel antenna is powered by a DC 28V cable, realizing a one-line combining circuit for RF signal and antenna power supply.

[0006] Furthermore, both the RF L transmitting port and the RF L receiving port of the low-orbit narrowband communication module are equipped with IPEX connectors, and the IPEX connectors are connected to the corresponding ports of the first RF combining module via RF0.81 RF cables.

[0007] Compared with the prior art, the present invention has the following beneficial effects: This terminal features a gigabit Ethernet interface that supports external switches for Ethernet interface expansion, and dual-band 2.4GHz / 5GHz Wi-Fi access capability. It can support multiple user devices to access the terminal via Ethernet and Wi-Fi. User devices automatically obtain IP addresses within the same subnet through DHCP and establish TCP connections with the terminal. The main processor of this terminal has a built-in embedded software communication protocol to realize service interaction between user devices and the terminal. User devices can access the terminal through B / S or C / S modes to obtain services such as LEO SMS, LEO Internet data services, LEO voice services, and BeiDou positioning. Attached Figure Description

[0008] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the overall hardware composition of this utility model.

[0009] Figure 2 This is a schematic diagram of the radio frequency combining module. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0011] Reference Figure 1 This embodiment includes a terminal host and an integrated communication and navigation antenna. The terminal host consists of a low-orbit narrowband communication module, a main processor, an Ethernet module, a wireless communication module, a Beidou positioning module, an RF combining module, a two-line telephone module, a power supply module, and an interface module. The terminal host and the integrated communication and navigation antenna are connected by an RF cable. The terminal host is connected to the user equipment through an Ethernet interface or a wireless WIFI interface. The main processor module supports Android and Linux operating systems, and can switch to the corresponding operating system according to actual development needs to realize the global control function of the terminal. It has built-in interface driver protocols for each module, and the serial port of the low-orbit narrowband communication module supports CMUX multiplexing protocol. It establishes corresponding CMUX serial port multiplexing channels for data streams such as protocol commands, voice, SMS, data, and logs to realize independent processing of data streams of each channel. The main processor is responsible for processing the Beidou module data protocol. It has built-in network layer protocol to support network terminal access management and routing and forwarding of low-orbit satellite networks. It supports a low-orbit dedicated voice vocoder to realize local telephone and remote telephone functions of low-orbit satellite Internet. The low-orbit narrowband communication module supports data communication rates of 2.4kbps to 300kbps, voice rates of 800kbps, 2.4kbps, and 4.8kbps, and SMS messages with a length not exceeding 140 bytes. The module is connected to the main processor via UART and PCM interfaces. The serial UART uses a 4Mbps baud rate for AT command control, and the PCM interface transmits 16-bit linear audio signals in master-slave mode. The PCM signal is the data format after audio encoding and decoding by the software vocoder built into the main processor module. The low-orbit narrowband communication module, model SCM2001CA, uses a level conversion chip (TXB0108PWR) to convert the UART and PCM interfaces to 1.8V and 3.3V levels before connecting to the corresponding interfaces of the main processor. The UART interface has a baud rate of 4Mbps and is used for communication data and command transmission. The PCM interface uses a 16-bit linear transmission mode for voice signal transmission. The Beidou positioning module, model ATGM336H-6N, is connected to the main processor via a UART interface and supports B1I, B1C frequency points and NMEA-0183 protocol to achieve Beidou positioning capability. The Ethernet module, model YT8521, supports Gigabit Ethernet mode. This module is connected to the main processor through the RMII interface and realizes Ethernet communication capability through the main processor's built-in Ethernet protocol stack driver. Users can access the terminal Ethernet through computer devices. The terminal's main control unit network layer supports DHCP dynamic address configuration protocol, NAT address forwarding protocol, and routing forwarding protocol, and dynamically maintains the IP and TCP data connections of the access host. A C / S access mode is implemented through dedicated client software to realize the user device's low-orbit narrowband Internet access request. The wireless communication module, model RTL8812, supports 2.4GHz / 5GHz dual-band WIFI. It is connected to the main processor via a USB interface and enables 2.4GHz / 5GHz dual-band WIFI access through the built-in WIFI AP driver in the main processor. Users can access the terminal network through WIFI-enabled devices such as mobile phones, which are on the same subnet as Ethernet devices. Through a dedicated APP in C / S mode, the communication terminal can make low-bandwidth Internet access requests.

[0012] The RF combiner module consists of two stages of RF combiners. The first stage of the RF combiner is connected to the IPEX connectors of the RF L transmitter and RF L receiver of the narrowband communication module via an RF0.81 RF cable. The RF signal of the first stage of the RF combiner module is connected to the RF signal of the Beidou positioning module via a 50Ω microstrip line on the board. After passing through the second stage of the RF combiner and the DC blocking circuit, the onboard RF line is superimposed with a DC 28V power supply to realize a single-line combination of RF signal and antenna power supply. It is connected to the integrated conduction antenna via an RF cable. The two-line telephone module connects to the main processor via a PCM signal interface. The two-line telephone module model is MYP4120. It supports 16-bit linear PCM signal modulation into a two-line telephone signal (TIP, RING). The terminal host has an RJ11 two-line telephone interface to connect to a telephone to realize local satellite telephone function. The integrated communication and navigation antenna connects to the radio frequency cable. The two ends of the radio frequency cable use TNC connectors. The length of the radio frequency cable is adjustable from 5 to 30 meters. It enables low-orbit narrowband L-frequency radio frequency transceiver and reception, amplification and filtering of BeiDou positioning signals. The interface module supports a dedicated SIM card for low-Earth orbit narrowband communication, an encrypted TF card, and a USB control interface for the low-Earth orbit narrowband module. The SIM card uses a MiniSIM card slot and connects to the SIM signal line of the low-Earth orbit narrowband communication module. The SIM card interface conforms to the ISO7816 standard. The encrypted TF card uses a MicroSD card slot and connects to the TF card signal line of the low-Earth orbit narrowband communication module. The USB control interface uses a USB-A interface. The telephone interface is an RJ11 dual-wire telephone port. The terminal casing has an interface cover, which allows for plugging and unplugging of each interface.

[0013] The power module supports the selection and switching between the internal battery module and the external 220V AC mains power, battery charging and discharging management, and step-down and regulated output of multiple DC power rails. It prioritizes the use of external mains power and outputs multiple power rails including 1.8V, 3.3V, 5V, and 28V DC to power the various functional modules of the circuit.

[0014] like Figure 2 As shown, the first-stage RF combiner combines the RF signals of the low-orbit narrowband L-band transmitter and L-band receiver; the second-stage RF combiner combines the L-band RF signal with the BeiDou received signal; the BeiDou received signal enters the BeiDou positioning module after passing through the BeiDou RF filter circuit; the combined signal of the low-orbit and BeiDou signals passes through the DC blocking circuit and is then superimposed with a DC 28V power supply to achieve a one-line combination of RF signal and antenna power supply. The first-stage RF combiner uses a duplexer model SFMD8C1521F7-1671F7A-R, the second-stage RF combiner uses a power divider model PD1500U03-140, the Beidou RF filter circuit model TA1584A, and the DC blocking circuit uses a 50V withstand voltage 1nF ceramic capacitor. All stages of combiners, filters, and DC blockers are connected through onboard 50Ω impedance microstrip lines. Low Earth Orbit (LEO) satellite narrowband communication process: The main processor runs the LINUX operating system and uses the CMUX (3GPP TS 27.010) serial port link multiplexing protocol through the UART interface to control data and commands with the LEO narrowband communication module. Three logical serial port channels are multiplexed through the CMUX protocol, namely the AT command channel, the network data channel, and the SMS data channel, with a serial port baud rate of 4Mbps. The uplink process for low-Earth orbit (LEO) communication is as follows: After the main processor sends a network access enable command to the LEO narrowband module via the AT command channel of the serial port, the LEO narrowband communication module activates the L receiving frequency to receive broadcast frames from LEO satellites. At the same time, the main processor performs ephemeris calculation to determine the distribution of satellites in the air. The main processor then writes the six ephemeris data into the LEO narrowband communication module. The module selects the beam with the best quality based on a comprehensive evaluation of the signal beam and satellite elevation angle and switches to it. The LEO narrowband communication module performs digital intermediate frequency encoding and modulates the data into a QPSK waveform according to the service request type (network access, SMS, voice, network data) and transmits it to the transmit carrier. The communication request information is transmitted to the integrated channel antenna via the L transmitting frequency. The antenna has a built-in 5W power amplifier, and the RF signal is amplified and transmitted to the LEO satellite to complete the communication transmission process.

[0015] The downlink process of LOR communication: The integrated antenna has a built-in 60dB low-noise amplifier at the L receiving frequency to amplify the received LOR satellite downlink signal. After passing through the filter circuit of the RF combiner module, it enters the LOR narrowband communication module. In the module, it undergoes downconversion and QPSK signal demodulation to the baseband digital signal. Then, the baseband chip outputs valid communication data to the main processor serial port (for network access, SMS, and network data services) or voice data to the PCM interface (for voice services). SMS, voice, and data services communicate bidirectionally with user terminal equipment through the wireless communication module and Ethernet module. Voice services can also be connected to local telephones by converting PCM voice data into analog two-line signals through the two-line telephone module.

[0016] BeiDou signal reception processing flow: The BeiDou signal received by the antenna is output through the BeiDou RF filtering circuit inside the RF combiner module and enters the BeiDou positioning module. It then passes through the LNA of the RF unit, down-converts to recover the intermediate frequency signal, and is quantized by the ADC to generate the baseband signal. The BeiDou positioning baseband chip extracts the pseudorange observation and calculates the three-dimensional coordinates, time information, and motion state parameters. The serial UART outputs the statement data stream following the NMEA-0183 protocol to the main processor module to realize the BeiDou positioning capability of the terminal.

[0017] It can support multiple user devices to access via Ethernet or wireless WIFI to obtain low-orbit satellite communication services and BeiDou positioning services, including low-orbit SMS, low-orbit Internet data services, low-orbit voice services, and BeiDou location services.

[0018] The terminal host and the integrated communication and conduction antenna are connected via an RF cable, and the terminal host is connected to the user equipment via an Ethernet interface or a wireless WIFI interface.

[0019] This terminal allows users to easily deploy equipment indoors and outdoors, quickly access the low-Earth orbit satellite communication network in unobstructed environments, and make satellite calls by connecting to a local landline phone. Alternatively, it can connect to multiple computers, mobile phones, and other devices via Ethernet or Wi-Fi interfaces. Through B / S or C / S service modes, users can access satellite internet services such as voice, data, SMS, and location via the low-Earth orbit narrowband communication terminal.

Claims

1. A low-orbit narrowband internet communication terminal supporting multi-device shared access, comprising a terminal host and an integrated communication and navigation antenna; characterized in that, The terminal host consists of a low-orbit narrowband communication module, a main processor, an Ethernet module, a wireless communication module, a Beidou positioning module, an RF combining module, and a two-line telephone module; The UART and PCM interfaces of the low-orbit narrowband communication module are connected to the corresponding interfaces of the main processor; the Beidou positioning module is connected to the main processor through the UART interface to realize Beidou positioning capability; the Ethernet module is connected to the main processor through the RMII interface to realize Ethernet communication capability; the wireless communication module is connected to the main processor through the USB interface to realize wireless WIFI access point capability; the two-line telephone module is connected to the main processor through the PCM signal interface, which is used to connect a telephone to realize local satellite telephone function. The RF L-transmit port of the low-orbit narrowband communication module is connected to the input terminal of the RF combiner module, and the RF L-receive port is connected to the output terminal of the RF combiner module; the RF combiner module is connected to the Beidou positioning module through the BDS port. The integrated communication and navigation antenna is connected to the radio frequency combining module via a radio frequency cable. Both ends of the radio frequency cable have TNC connectors to realize the reception, amplification and filtering of low-orbit narrowband L-frequency radio frequency transceiver and BeiDou positioning signals.

2. A low-orbit narrowband internet communication terminal supporting multi-device shared access according to claim 1, characterized in that, The radio frequency combining module consists of a Beidou radio frequency filtering circuit, a DC blocking circuit, and a two-stage radio frequency combining circuit. The input and output ports of the first-stage radio frequency combining circuit are connected to the RF L transmitting port and RF L receiving port of the low-orbit narrowband communication module, respectively. The radio frequency signal of the Beidou radio frequency filtering circuit and the Beidou positioning module are connected by a 50Ω microstrip line on the board. The common terminal of the first-stage radio frequency combining circuit and the input terminal of the Beidou radio frequency filtering circuit are connected to the branch port of the second-stage radio frequency combining circuit, respectively. The combining port of the second-stage radio frequency combining circuit is connected to the integrated antenna through the DC blocking circuit. The onboard radio frequency cable between the DC blocking circuit and the integrated antenna is powered by a DC 28V cable, realizing a one-line combining circuit for radio frequency signal and antenna power supply.

3. A low-orbit narrowband internet communication terminal supporting multi-device shared access according to claim 2, characterized in that, Both the RF L transmitting port and the RF L receiving port of the low-orbit narrowband communication module are equipped with IPEX connectors. The IPEX connectors are connected to the corresponding ports of the first RF combining module via RF0.81 RF cables.

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