Synchronous access system and method based on MF-TDMA system

Abstract

The invention belongs to the technical field of communication and information systems, and particularly relates to a synchronous access system and method based on an MF-TDMA system. Comprising a signal processing device, a synchronous access device and a control device, the signal processing device receives, processes, demodulates and decodes forward downlink signals of a VSAT master station and reverse uplink signals of a VSAT small station, and analyzes and restores signaling and service data information of system master station and small station communication; the synchronous access device comprises a system synchronization module, a time difference calculation module, a time delay test module and an excitation generation module. The VSAT satellite communication network space link signal synchronous access method has the advantages that a satellite system synchronization technology, a position data-based time synchronization algorithm, a space time delay measurement technology and an MF-TDMA channel real-time tracking technology are used for carrying out space link signal synchronous access on a VSAT satellite communication network; synchronous access of a space signal link of the VSAT satellite network is realized by using methods based on VSAT satellite system synchronization mechanism analysis processing, system reverse channel resource monitoring, idle time slot signal measurement, MF-TDMA system emission time calculation and the like, and the method can provide technical support for further signaling and service data access and information management and control. And smart and efficient management and control of the VSAT satellite communication network are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of communication and information systems, and in particular relates to a synchronous access system and method based on an MF-TDMA system. Background Art

[0002] A typical VSAT satellite communication network can provide IP-based voice, video, fax, data, internet and other service applications. Due to its advanced technical system, multiple terminal types and a wide range of services it can provide, it is widely used in commercial fields such as offshore and oil and gas, as well as government fields.

[0003] A typical VSAT satellite communication network is mainly composed of three parts: a satellite ground master station, a satellite, and a VSAT small station. Similar to the communication process of a ground mobile network terminal, after the VSAT small station is turned on, it is necessary to complete the registration and login process in the VSAT satellite communication network, that is, to verify the legitimacy of the small station / network identity, and to confirm the communication service level and channel rate and other operations. Then it will enter the business communication stage, receive the forward downlink business data, send the reverse uplink business data, and after the business data transmission is completed, perform the deregistration / offline process and release the corresponding physical channel resources. Therefore, the space signal link between the satellite and the ground master station / small station has become the main regulatory and control link for the VSAT satellite communication network.

[0004] The synchronous access technology and method based on the MF-TDMA system, that is, through the signal synchronization technology based on the typical VSAT satellite communication reverse channel MF-TDMA system, the space access function of the VSAT satellite communication network is realized, and the corresponding return uplink signaling or business data can be constructed according to the received target VSAT satellite communication forward downlink signal parameters, and transmitted in combination with appropriate signal power values, so as to provide a space access channel for VSAT satellite communication control. Summary of the invention

[0005] The purpose of the present invention is to provide a synchronous access system and method based on the MF-TDMA system, which realizes synchronization with the system by receiving the downlink system message forwarded by the VSAT satellite master station, obtaining the relevant parameters for calculating synchronization, combining the position information of the target communication VSAT small station to calculate the delay value and the idle time slot signal transmission delay measurement value, and transmitting on the MF-TDMA reverse uplink frequency and time slot resources allocated by the system, so as to realize the synchronous access function in the VSAT satellite network.

[0006] The technical solution of the present invention is as follows: a synchronous access system based on the MF-TDMA system, comprising a signal processing device, a synchronous access device and a control device, wherein the signal processing device receives and processes the forward downlink signal of the VSAT master station and the reverse uplink signal of the VSAT small station, demodulates, decodes and parses and restores the signaling and service data information of the system master station and the small station communication;

[0007] The synchronous access device includes a system synchronization module, a time difference calculation module, a delay test module and an excitation generation module;

[0008] Among them, the system synchronization module maintains the system synchronization function according to the system synchronization parameters, the time difference calculation module calculates the access time compensation difference according to the VSAT station location information, the delay test module measures the spatial delay by transmitting the test signal, and the stimulus generation module completes the generation of the access signal;

[0009] The control device sets parameters, performs operation control and displays status of signal processing equipment and synchronous access equipment.

[0010] A synchronous access method based on MF-TDMA system comprises the following steps:

[0011] Step 1: Receive the two-way communication signals of the main station and the small station of the VSAT satellite communication system and analyze the data;

[0012] Step 2: Analyze the downlink system information from the VSAT system master station, obtain relevant parameters for calculating synchronization, and achieve synchronization with the system;

[0013] Step 3: Calculate the time delay difference between the VSAT station and the satellite according to the current location information of the VSAT station;

[0014] Step 4: Use the idle time slot to transmit the test signal to obtain the spatial signal transmission delay and the time advance of the access signal transmission and the power control parameters;

[0015] Step 5: Use real-time monitoring of MF-TDMA reverse uplink frequency and time slot allocation information to automatically control transmission channel parameters.

[0016] The step 1 uses the VSAT satellite communication system master station and small station communication as a test platform, first establishes a VSAT typical satellite communication network, the VSAT master station establishes a communication link with the small station, and receives and processes the forward downlink signal of the master station and the reverse uplink signal of the small station respectively. First, the received two-way communication signal is demodulated and decoded, the decoded signaling and service frame are separated, and the corresponding information frame is parsed, and each communication signaling parameter and service data content are extracted according to the information frame type and format.

[0017] The step 2 analyzes the downlink system information from the VSAT system master station through a signal processing device, extracts the system synchronization parameters according to the information type after demodulation and decoding, obtains the relevant parameters for calculating synchronization, and sends them to the system synchronization module, determines the timing offset from the local clock through the system synchronization parameters, and updates the timing offset in real time by real-time monitoring of the downlink signal reception processing from the VSAT system master station, so as to achieve and maintain real-time synchronization with the system.

[0018] The step 3 uses the latitude and longitude position information of the target VSAT communication station, the current latitude and longitude position information of the synchronous access device, and the communication satellite position vector value as input parameters, calculates the delay value delay between the terminal and the satellite through the latitude and longitude position information and the satellite vector value, and then calculates the time delay difference caused by the difference in position information of the VSAT communication station and the synchronous access device, and compensates it to the transmission time of the access signal.

[0019] The step 4, based on the real-time monitoring of the communication between the VSAT master station and the small station, utilizes the idle time slot channel resources of the reverse link of the target system, transmits a test signal through the delay test module, obtains the spatial signal transmission delay and the time advance of the access signal transmission and the power control parameters, so as to further accurately synchronize the transmission time compensation and set the access signal transmission power value.

[0020] The step 5 is to monitor the target VSAT satellite system reverse link MF-TDMA system frequency and time slot channel allocation information in real time through the signal processing equipment, automatically control the transmission channel parameters of the synchronous access equipment, combine the system synchronization parameters, the position information time difference, the measured delay and advance, obtain the transmission frequency and time slot T time slot according to the reverse link MF-TDMA system frequency and time slot channel allocation information, determine the timing offset TRX according to the system synchronization parameters to calculate the transmission timestamp, and perform time compensation on the transmission timestamp through the position information time difference TCH, the measured delay and advance TCL, and finally generate an access excitation signal with the synchronous access time of TTX=TRX+T time slot+TCH+TCL.

[0021] The beneficial effects of the present invention are as follows: the present invention performs signal synchronization access to the space link of the VSAT satellite communication network by utilizing satellite system synchronization technology, a time synchronization algorithm based on position data, a space delay measurement technology and a MF-TDMA channel real-time tracking technology; and uses methods based on VSAT satellite system synchronization mechanism analysis and processing, system reverse channel resource monitoring, idle time slot signal measurement, MF-TDMA system transmission time calculation and the like to achieve synchronous access to the space signal link of the VSAT satellite network. The method can provide technical support for further signaling and service data access and information control, and achieve smart and efficient control of the VSAT satellite communication network. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the schematic diagram of VSAT satellite communication space synchronous access;

[0023] Figure 2 A schematic diagram of a synchronous access system based on the MF-TDMA system provided by the present invention;

[0024] Figure 3 The present invention provides a flow chart of a synchronous access method based on the MF-TDMA system. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] First, the abbreviations and key terms involved in the present invention are uniformly explained as follows:

[0027] Forward: The direction from the satellite ground main station to the satellite communication station via the satellite.

[0028] Reverse direction: The direction from the satellite communication station to the satellite ground main station via the satellite.

[0029] Downlink: The direction from satellite to communication station or from satellite to ground main station.

[0030] Uplink: The direction from a communication station to a satellite or from a ground station to a satellite.

[0031] like Figure 2 As shown, a synchronous access system based on the MF-TDMA system includes a signal processing device, a synchronous access device and a control device. The synchronous access device includes a system synchronization module, a time difference calculation module, a delay test module and an excitation generation module.

[0032] The signal processing equipment mainly completes the reception and processing functions of the forward downlink signal of the VSAT master station and the reverse uplink signal of the VSAT small station. It can demodulate, decode and parse and restore the signaling and business data information of the system master station and small station communication.

[0033] The synchronous access equipment mainly completes the functions of synchronization parameter calculation and access excitation signal generation based on the MF-TDMA system, including system synchronization module, time difference calculation module, delay test module and excitation generation module. Among them, the system synchronization module completes the function of maintaining synchronization with the system according to the system synchronization parameters, the time difference calculation module completes the function of calculating the access time compensation difference according to the location information of the VSAT small station, the delay test module completes the function of measuring the spatial delay by transmitting the test signal, and the excitation generation module completes the function of generating the access signal.

[0034] The control equipment mainly completes the functions of parameter setting, operation control and status display of signal processing equipment and synchronous access equipment.

[0035] like Figure 3 As shown, a synchronous access method based on the MF-TDMA system includes the following steps:

[0036] Step 1: Receive the two-way communication signals from the main station and small station of a typical VSAT satellite communication system and analyze the data

[0037] Using the master station and small station communication of a typical VSAT satellite communication system as the test platform, a typical VSAT satellite communication network is first established, and a communication link is established between the VSAT master station and the small station. The forward downlink signal of the master station and the reverse uplink signal of the small station are received and processed respectively. First, the received two-way communication signal is demodulated and decoded, and the decoded signaling and service frames are separated, and the corresponding information frames are parsed, and the communication signaling parameters and service data content are extracted according to the information frame type and format.

[0038] Step 2: Analyze the downlink system information from the VSAT system master station, obtain relevant parameters for calculating synchronization, and achieve synchronization with the system;

[0039] The signal processing equipment analyzes the downlink system information from the VSAT system master station, and after demodulation and decoding, extracts the system synchronization parameters according to the information type, obtains the relevant parameters for calculating synchronization, and sends them to the system synchronization module. The timing offset with the local clock is determined by the system synchronization parameters, and the timing offset is updated in real time by real-time monitoring of the downlink signal reception processing from the VSAT system master station, so as to achieve and maintain real-time synchronization with the system.

[0040] Step 3: Calculate the time delay difference between the VSAT station and the satellite according to the current location information of the VSAT station;

[0041] Based on the latitude and longitude position information of the target VSAT communication station, the current latitude and longitude position information of the synchronous access device, and the communication satellite position vector value as input parameters, the time difference calculation module software algorithm can first calculate the delay value delay between the terminal and the satellite through the longitude and latitude position information and the satellite vector value, and then calculate the time delay difference caused by the difference in the position information of the VSAT communication station and the synchronous access device, and compensate it to the transmission time of the access signal.

[0042] Step 4: Use the idle time slot to transmit the test signal to obtain the spatial signal transmission delay, the time advance of the access signal transmission, and the power control parameters

[0043] On the basis of realizing real-time monitoring of the communication between the VSAT master station and the small station, the idle time slot channel resources of the reverse link of the target system are utilized to transmit the test signal through the delay test module to obtain the spatial signal transmission delay and the time advance of the access signal transmission and the power control parameters, so as to further accurately synchronize the transmission time compensation and set the parameters such as the access signal transmission power value.

[0044] Step 5: Use real-time monitoring of MF-TDMA reverse uplink frequency and time slot allocation information to automatically control transmission channel parameters

[0045] The signal processing equipment monitors the target VSAT satellite system reverse link MF-TDMA system frequency and time slot channel allocation information in real time, automatically controls the transmission channel parameters of the synchronous access equipment, combines the system synchronization parameters, the position information time difference, the measured delay and advance, obtains the transmission frequency and time slot T slot according to the reverse link MF-TDMA system frequency and time slot channel allocation information, determines the timing offset TRX according to the system synchronization parameters, calculates the transmission timestamp, and compensates the transmission timestamp by the position information time difference TCH and the measured delay and advance TCL. The final synchronous access time is TTX=TRX+T slot+TCH+TCL, and generates an access excitation signal.

Claims

1. A synchronous access system based on MF-TDMA system, characterized in that: It includes signal processing equipment, synchronous access equipment and control equipment. The signal processing equipment receives and processes the forward downlink signal of the VSAT master station and the reverse uplink signal of the VSAT small station, demodulates, decodes and analyzes and restores the signaling and business data information of the system master station and small station communication; The synchronous access device includes a system synchronization module, a time difference calculation module, a delay test module and an excitation generation module; Among them, the system synchronization module maintains the system synchronization function according to the system synchronization parameters, the time difference calculation module calculates the access time compensation difference according to the VSAT station location information, the delay test module measures the spatial delay by transmitting the test signal, and the stimulus generation module completes the generation of the access signal; The control device sets parameters, performs operation control and displays status of signal processing equipment and synchronous access equipment.

2. A synchronous access method based on MF-TDMA system, characterized in that: The steps include: Step 1: Receive the two-way communication signals of the main station and the small station of the VSAT satellite communication system and analyze the data; Step 2: Analyze the downlink system information from the VSAT system master station, obtain relevant parameters for calculating synchronization, and achieve synchronization with the system; Step 3: Calculate the time delay difference between the VSAT station and the satellite according to the current location information of the VSAT station; Step 4: Use the idle time slot to transmit the test signal to obtain the spatial signal transmission delay and the time advance of the access signal transmission and the power control parameters; Step 5: Use real-time monitoring of MF-TDMA reverse uplink frequency and time slot allocation information to automatically control transmission channel parameters.

3. A synchronous access method based on MF-TDMA system as claimed in claim 2, characterized in that: The step 1 uses the VSAT satellite communication system master station and small station communication as a test platform, first establishes a VSAT typical satellite communication network, the VSAT master station establishes a communication link with the small station, and receives and processes the forward downlink signal of the master station and the reverse uplink signal of the small station respectively. First, the received two-way communication signal is demodulated and decoded, the decoded signaling and service frame are separated, and the corresponding information frame is parsed, and each communication signaling parameter and service data content are extracted according to the information frame type and format.

4. A synchronous access method based on MF-TDMA system as claimed in claim 2, characterized in that: The step 2 analyzes the downlink system information from the VSAT system master station through a signal processing device, extracts the system synchronization parameters according to the information type after demodulation and decoding, obtains the relevant parameters for calculating synchronization, and sends them to the system synchronization module, determines the timing offset from the local clock through the system synchronization parameters, and updates the timing offset in real time by real-time monitoring of the downlink signal reception processing from the VSAT system master station, so as to achieve and maintain real-time synchronization with the system.

5. A synchronous access method based on MF-TDMA system as claimed in claim 2, characterized in that: The step 3 uses the latitude and longitude position information of the target VSAT communication station, the current latitude and longitude position information of the synchronous access device, and the communication satellite position vector value as input parameters, calculates the delay value delay between the terminal and the satellite through the latitude and longitude position information and the satellite vector value, and then calculates the time delay difference caused by the difference in position information of the VSAT communication station and the synchronous access device, and compensates it to the transmission time of the access signal.

6. A synchronous access method based on MF-TDMA system as claimed in claim 2, characterized in that: The step 4, based on the realization of real-time monitoring of the communication between the VSAT master station and the small station, utilizes the idle time slot channel resources of the reverse link of the target system, transmits a test signal through the delay test module, obtains the spatial signal transmission delay and the time advance of the access signal transmission and the power control parameters, so as to further accurately synchronize the transmission time compensation and set the access signal transmission power value.

7. A synchronous access method based on MF-TDMA system as claimed in claim 2, characterized in that: The step 5 is to monitor the target VSAT satellite system reverse link MF-TDMA system frequency and time slot channel allocation information in real time through the signal processing equipment, automatically control the transmission channel parameters of the synchronous access equipment, combine the system synchronization parameters, the position information time difference, the measured delay and advance, obtain the transmission frequency and time slot T time slot according to the reverse link MF-TDMA system frequency and time slot channel allocation information, determine the timing offset TRX according to the system synchronization parameters to calculate the transmission timestamp, and perform time compensation on the transmission timestamp through the position information time difference TCH, the measured delay and advance TCL, and finally generate an access excitation signal with the synchronous access time of TTX=TRX+T time slot+TCH+TCL.

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