KR102658345B1 - Method, system and apparatus for transmitting and receiving differential correction data packets - Google Patents

Abstract

This disclosure relates to positioning technology and discloses a method, system, and device for transmitting and receiving differential correction data packets. The server end sends the first differential correction data to the user terminal in the first information period. The number of bits occupied by the quality factor data in the first differential correction data packet is A (step 101), and the number of bits occupied by the quality factor data in the first differential correction data packet is A (step 101), In at least one continuous information period, the server end sends a second differential correction data packet to the user terminal, and the number of bits occupied by the quality factor data in the second differential correction data packet is B, where A > B In addition, A and B are positive integers (step 102), and by drastically reducing the amount of SSR information transmission based on the existing RTCM format, transmission costs and time can be greatly saved.

Description

Method, system and apparatus for transmitting and receiving differential correction data packets

This application relates to positioning technology, and in particular to technology for transmitting and receiving differential correction data packets.

Currently, there are several encoding formats adopted internationally for transmitting high-precision correction data packets by satellite. For example, existing satellites transmit a standard RTCM format to the receiving end by frequency modulation for real-time positioning and Calibration is possible, but the amount of data is large and the transmission time is long. SSR1-3 has a single transmission data size of several million bits (see web page 1); The compact SSR technology standard adopted by the existing QZSS applies only to mainland Japan, most of which do not meet the positioning needs of China, and the size of one-time transmission data of SSR1-3 is one million bits. (see web page 2). However, in a specific PPP-RTK technology, no format has been able to solve the compression problem of the information encoding format under the requirements of high concurrency and low latency, which increases channel multiplexing and reduces utilization.

This application provides a method, system, and device for transmitting and receiving differential correction data packets, and aims to save a large amount of transmission cost and time by drastically reducing the amount of SSR information transmission based on the existing RTCM format. .

The present application includes the steps of a server end sending a first differential correction data packet to a user terminal in a first information period, wherein the number of bits occupied by quality factor data in the first differential correction data packet is A; In at least one consecutive information period after the first information period, the server end sends a second differential correction data packet to the user terminal, wherein the bit occupied by the quality factor data in the second differential correction data packet A number is B, where A > B and A and B are positive integers. A method of transmitting a differential correction data packet comprising a step is disclosed.

In a preferred example, the packet header of the differential correction data packet includes an identification bit indicating whether the number of bits occupied by quality factor data in the packet is A bit or B bit.

In a preferred example, the first differential correction data packet further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein the first differential correction data packet includes quality factor data. corresponds to the first, second, third and fourth model polynomial coefficient data of the first differential correction data packet,

The second difference correction data packet further includes satellite identification data, first, second, third, and fourth model polynomial coefficient data, wherein the quality factor data in the second difference correction data packet is the second difference correction data. Among the correction data packets, they correspond to the first, second, third and fourth model polynomial coefficient data.

In a preferred example, the quality factor data in the first differential correction data packet is total quality factor data, and the quality factor data in the second differential correction data packet is incremental quality factor data.

In one preferred example, the quality factor data in the second differential correction data packet is an increment of the current quality factor data.

In a preferred example, before the server end sends the first differential correction data packet to the user terminal in the first information period,

the server end receiving state space display method correction data sent from a satellite in each information period;

A server end performing encoding format calculation on the state space display method correction data to generate quality factor data among the corresponding first difference correction data packets or quality factor data among the second difference correction data packets; Includes more.

The present application also provides a method of sending a first differential correction data packet to a user terminal in a first information period, and sending a second differential correction data packet to the user terminal in at least one successive information period after the first information period. A first transmission module, wherein the number of bits occupied by the quality factor data in the first differential correction data packet is A, the number of bits occupied by the quality factor data in the second differential correction data packet is B, and A > B, and Initiates a transmission system of differential correction data packets, where A and B are positive integers.

In a preferred example, the packet header of the differential correction data packet includes an identification bit indicating whether the number of bits occupied by quality factor data in the packet is A bit or B bit.

In a preferred example, the first differential correction data packet further includes satellite identification data, first, second, third and fourth model polynomial coefficient data, wherein the first differential correction data packet includes quality factor data. corresponds to the first, second, third and fourth model polynomial coefficient data of the first differential correction data packet,

The second difference correction data packet further includes satellite identification data, first, second, third, and fourth model polynomial coefficient data, wherein the quality factor data in the second difference correction data packet is the second difference correction data. Among the correction data packets, they correspond to the first, second, third and fourth model polynomial coefficient data.

In a preferred example, the quality factor data in the first differential correction data packet is total quality factor data, and the quality factor data in the second differential correction data packet is incremental quality factor data.

In one preferred example, the quality factor data in the second differential correction data packet is an increment of the current quality factor data.

In a preferred example, it further comprises a first receiving module and a calculating module,

The first receiving module is used to receive state space indication method correction data sent from the satellite in each information period,

The calculation module is used to perform encoding format calculation on the state space representation method correction data to generate corresponding quality factor data among the first difference correction data packet or quality factor data among the second difference correction data packet. do.

The present application also includes the steps of a user terminal receiving a differential correction data packet sent from a server end;

determining, by the user terminal, whether the quality factor data received in the differential correction data packet is an A bit or a B bit, where A > B and A and B are positive integers;

If the received quality factor data is A bit, updating the current quality factor data with the A bit quality factor data;

When the received quality factor data is B bit, updating the quality factor data according to the current quality factor data and the B bit quality factor data. A method of receiving a differential correction data packet including a step is disclosed.

In a preferred example, the user terminal determines whether the received quality factor data in the differential correction data packet is an A bit or a B bit,

The user terminal identifies whether the quality factor data is an A bit or a B bit according to an identification bit in the packet header of the differential correction data packet.

In one preferred example, the A-bit quality factor data is total quality factor data, and the B-bit quality factor data is incremental quality factor data.

In one preferred example, the B bits of quality factor data are increments of the current quality factor data.

The present application also includes a second receiving module for receiving a differential correction data packet from the server end;

a decision module that determines whether the quality factor data received among the differential correction data packets is an A bit or a B bit;

If the received quality factor data is A bit, the current quality factor data is updated with the A bit quality factor data, and if the received quality factor data is B bit, the current quality factor data and the B bit quality factor data are updated. Accordingly, a processing module for updating the current quality factor data;

Herein, a system for receiving differentially corrected data packets is disclosed, where A > B and A and B are positive integers.

In one preferred example, the determination module is also used to identify whether the quality factor data is an A bit or a B bit, according to an identification bit in a packet header of the differential correction data packet.

In one preferred example, the A-bit quality factor data is total quality factor data, and the B-bit quality factor data is incremental quality factor data.

In one preferred example, the B bits of quality factor data are increments of the current quality factor data.

The present application also provides a memory for storing instructions executable on a computer;

A processor implementing the steps of the above-described transmission method when executing instructions executable on the computer. Disclosed is a transmission device for differential correction data packets, comprising:

The present application also provides that, in the computer-readable storage medium, computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, the computer-readable storage medium implements the steps of the above-described transmission method. begins.

The present application also provides a memory for storing instructions executable on a computer;

Disclosed is an apparatus for receiving differential correction data packets, comprising a processor that, when executing instructions executable on the computer, implements the steps of the receiving method described above.

The present application also provides that, in the computer-readable storage medium, computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, the computer-readable storage medium implements the steps of the above-described reception method. begins.

In the embodiment of the present application, in the PPP-RTK positioning technology, the atmospheric correction data format of the corresponding area is encoded in a flexibly orchestratable manner to achieve the effect of compressing the entire data amount.

In the embodiment of the present application, first, based on the existing RTCM format, the orchestration and transmission method of the quality factor data in the differential correction data packet format is optimized, and the overall quality factor data and the incremental quality factor data are combined to produce the corresponding differential correction data. Send packets. Among them, through the transmission of incremental quality factor data, the transmission amount of differential correction data packets is greatly reduced, transmission costs and time are greatly saved, data is simplified, and synchronous satellite signal transmission distance is long. It can reduce the increase in code error rate caused by severe weakness. Furthermore, by sending the entire quality factor data once on a regular or irregular basis, the terminal of a newly registered user obtains the raw amount (full data), thereby reducing the amount of information compression and improving the user precision of each user's terminal. Guaranteed.

Furthermore, for the QZSS code system, technical indicators can be redefined according to various needs, so that the modified information maintains high precision and is consistent with different geographical situations, land area, and atmospheric conditions. For example, in optimizing orchestration according to China's geographical situation, first, QI's Class and Value orchestration method can be optimized by region, and in order to maintain a constant resolution on the map, according to the calculation of formula (1), The data in Table 2 can be obtained, but in actual application situations, such a design is not needed for all of China. China is very large from north to south, and the atmospheric activity in the northern region is not intense, so very fine resolution is not needed. Most data is relatively gentle, so it can be quantified in a small range, and the atmospheric activity in the southern region of China is not intense. Well, only small areas need to adopt a design like this. In the SSR correction quantity information, under the premise of ensuring a certain resolution, upper and lower limits must be set for the activation degree of the ionosphere above the current area, otherwise the positioning effect cannot be achieved and may even have adverse effects. . The degree of activation of the ionosphere itself is strongly related to latitude, that is, the closer to the equator the more active the ionosphere is, the wider the correction amount range and the smaller the resolution, resulting in an increase in the amount of data. In the embodiment herein, the technical indicators (correction range, grid range, etc.) are redefined based on China's national situation, so that the correction information maintains high precision and at the same time conforms to China's geographical situation, land area and atmospheric conditions. do.

A large number of technical features are described in the specification of the present application and are distributed to each technical means. If one attempts to list all possible combinations of technical features (i.e., technical means) of the present application, the specification will become too verbose. In order to avoid this problem, each technical feature disclosed in the above-described invention content of the present application, each technical feature disclosed in each embodiment and example below, and each technical feature disclosed in the accompanying drawings, a combination of these technical features can be technically implemented. Except in cases where this is impossible, all can be freely combined with each other to form various new technical means (all such technical means are considered to be described in this specification). For example, if features A+B+C are disclosed in one example and features A+B+D+E are disclosed in another example, and features C and D are equivalent technical means performing the same function, then technically You can select one and use it, but they cannot be used at the same time. If feature E is technically combinable with feature C, the means of A+B+C+D are not considered as described because they are technically infeasible, and A The means of +B+C+E are considered as stated.

1 is a flowchart of a method for transmitting a differential correction data packet according to a first embodiment of the present application.
Figure 2 is a schematic diagram of packet head related bits according to an embodiment of the present application.
Figure 3 is a structural schematic diagram of a transmission system for differential correction data packets according to the second embodiment of the present application.
Figure 4 is a flowchart of a method for receiving a differential correction data packet according to a third embodiment of the present application.
Figure 5 is a structural schematic diagram of a receiving system for differential correction data packets according to the fourth embodiment of the present application.

In the description below, numerous technical details are presented to enable the reader to better understand the subject matter. However, those skilled in the art can understand that the technical means sought to be protected by the present application can be implemented without various changes and modifications based on these technical details and each embodiment below.

An explanation of some concepts is below.

Global Navigation Satellite System, abbreviated as GNSS.

BeiDou navigation satellite system (BDS navigation Satellite system, abbreviated as BDS).

State Space Representation, abbreviated as SSR.

Precise Point Positioning, abbreviated as PPP.

Real Time Kinematic, abbreviated as RTK.

Transmission Control/Internet Protocol, abbreviated as TCP/IP.

Networked Transport of RTCM via Internet, abbreviated as NTRIP.

Radio Technical Commission for Maritime Services, abbreviated as RTCM.

Quasi-Zenith Satellite System, abbreviated as QZSS.

Total Electron Content Unit, abbreviated as TECU.

Quality Indicator, abbreviated as QI.

In order to make the purpose, technical means and advantages of the present application clearer, the embodiments of the present application will be described in more detail below in combination with the attached drawings.

A first embodiment of the present application relates to a method of transmitting a differential correction data packet, which method includes the following steps as shown in FIG. 1.

Starting, step 101 is performed, wherein the server end sends a first differential correction data packet to the user terminal in a first information period, wherein the quality factor data (QI _A ) occupies the first differential correction data packet. The number of bits is A.

Optionally, before step 101, the following sub-steps A and B may be further included. Starting to perform sub-step A, the server side receives state space display method correction data sent from the satellite in each information period. Next, sub-step B is performed, where the server end performs encoding format calculation on the state space display method correction data to generate a corresponding first difference correction data packet or second difference correction data packet.

Next, step 102 is performed, wherein in at least one consecutive information period after the first information period, the server end sends a second differential correction data packet to the user terminal, wherein the second differential correction data packet is The number of bits occupied by the quality factor data (QI _B ) is B, where A > B and A and B are positive integers.

Typically, the first and second differential correction data packets are formatted data blocks. Optionally includes a start line that describes the packet, optionally includes a header block (or packet header/header) containing attributes, and optionally includes a body part (or body) containing data. .

In one embodiment, the first and second differential correction data packets include a header and a body, respectively.

Optionally, the body of the first differential correction data packet includes A-bit quality factor data, and the body of the second differential correction data packet includes B-bit quality factor data. Optionally, the body of the first differential correction data packet further includes satellite identification data, first, second, third and fourth model polynomial coefficient data (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ); Here, the quality factor data (QI _A ) in the first difference correction data packet corresponds to the first, second, third, and fourth model polynomial coefficient data in the first difference correction data packet. Optionally, the body of the second differential correction data packet includes satellite identification data, first, second, third and fourth model polynomial coefficient data (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ), where: , the quality factor data (QI _B ) in the second difference correction data packet corresponds to the first, second, third and fourth model polynomial coefficient data in the second difference correction data packet.

Optionally, the header of the first and second differential correction data packets includes an identification bit indicating whether the number of bits occupied by quality factor data in the packet is A bits or B bits. Figure 2 is a schematic diagram of bits related to a packet header (ie, header) in a specific embodiment of the present application. Among them, adding a 1-bit identification bit called "STEC TYPE (the name is only an example and there is no limitation in actual application)" to the header means that the "quality factor data" is 6 bits when used by the user (in the user terminal). , This is to be able to actively recognize whether it is 1 bit. Specifically, the role of "STEC TYPE" is that if the field is "1", the "quality factor data (QI _A )" in the SSR information following the packet header is 1 bit long, and similarly, if the field is "0" If so, it indicates that the “quality factor data (QI _A )” in the SSR information following the corresponding packet header is 6 bits. 1 bit and 6 bits in FIG. 2 are only specific examples of quality factor data length, and in actual application, it can be adjusted depending on the situation, for example, 2 bits or 6 bits, 3 bits and 6 bits, etc.

Optionally, the quality factor data of the A bits of the first differential correction data packet is total quality factor data, and the quality factor data of the B bits of the second differential correction data packet is incremental quality factor data.

There are several ways in which the corresponding server sends the first or second differential correction data. Optionally, the server end sends the first differential correction data packet at a fixed period, for example, each N information period is one fixed period, that is, the first and Nth information periods are all transmissions, and the remaining is an incremental dispatch. Optionally, the server end sends the first differential correction data irregularly, for example, the first information period is full transmission, the second and third information periods are incremental transmission, and the fourth information period is full transmission. , the 5th, 6th, and 7th information cycles are incremental transmissions, the 8th information cycle is full transmissions, the 9th, 10th, 11th, and 12th information cycles are incremental transmissions,... … It can be sent by mail, etc.; For example, the first information cycle is full transmission, the second and third information cycles are incremental transmission, the fourth information cycle is full transmission, and the fifth, sixth, seventh, eighth, and ninth information cycles are It is an incremental dispatch, the 10th information period is a full dispatch, the 11th, 12th, 13th, 14th, 15th information period is an incremental dispatch, … … It can be sent by, etc. Among the above-described first differential correction data packets, the A-bit (or total) quality factor data is sent regularly or irregularly, allowing the newly registered user terminal to obtain the raw quantity. Therefore, not only does it guarantee user precision, but it also guarantees a certain amount of information compression.

Optionally, the quality factor data of the B bit in the second differential correction data packet is an identifier indicating the current quality factor data change. For example, if the B bit is “1 bit”, where 1 bit is an identifier indicating the current quality factor data change and is 1 or 0, identifier 1 indicates decrease and identifier 0 indicates increase. In another embodiment, the quality factor data of the B bit in the second differential correction data packet is an increment of the current quality factor data.

The second embodiment of the present application relates to a transmission system for differential correction data packets, the structure of which is as shown in Figure 3, and the transmission system for differential correction data packets includes a first transmission module. The first transmission module is configured to send a first differential correction data packet to the user terminal in a first information period, and to send a second differential correction data packet to the user terminal in at least one successive information period after the first information period. It is used to send, where the number of bits occupied by the quality factor data (QI _A ) in the first differential correction data packet is A, and the number of bits occupied by the quality factor data (QI _B ) in the second differential correction data packet is B. , A > B, and A and B are positive integers.

Typically the first and second differential correction data packets are formatted data blocks. Optionally contains a start line that describes the packet, optionally contains a header block (or packet header/header) containing attributes, and optionally contains a body part (or body) containing data. do.

In one embodiment, the first and second differential correction data packets include a header and a body, respectively.

Optionally, the body of the first differential correction data packet includes A-bit quality factor data, and the body of the second differential correction data packet includes B-bit quality factor data. Optionally, the body of the first differential correction data packet further includes satellite identification data, first, second, third and fourth model polynomial coefficient data (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ). Here, the quality factor data (QI _A ) in the first difference correction data packet corresponds to the first, second, third, and fourth model polynomial coefficient data in the first difference correction data packet. Optionally, the body of the second differential correction data packet further includes satellite identification data, first, second, third and fourth model polynomial coefficient data (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ); Here, the quality factor data (QI _B ) in the second difference correction data packet corresponds to the first, second, third, and fourth model polynomial coefficient data in the second difference correction data packet.

Optionally, the header of the first and second differential correction data packets includes an identification bit indicating whether the number of bits occupied by the quality factor data of the packet is A bits or B bits. Figure 2 is a schematic diagram of bits related to a packet header (i.e., header) in a specific embodiment of the present application. Among them, adding a 1-bit identification bit called "STEC TYPE (the name is only an example and there is no limitation in actual application)" to the header means that the "quality factor data" is 6 bits when used by the user (in the user terminal). This is to be able to actively recognize whether it is 1 bit. Specifically, the role of "STEC TYPE" is that if the field is "1", the "quality factor data (QI _B )" in the SSR information following the packet header is 1 bit long, and similarly, if the field is "0" If so, it indicates that the “quality factor data (QI _A )” in the SSR information following the corresponding packet header is 6 bits.

1 bit and 6 bits in FIG. 2 are only specific examples of quality factor data length, and in actual application, it can be adjusted depending on the situation, for example, 2 bits or 6 bits, 3 bits and 6 bits, etc. Optionally, the quality factor data of the A bits is total quality factor data, and the quality factor data of the B bits is incremental quality factor data.

There are several ways in which the corresponding server sends the first or second differential correction data. Optionally, the server end sends the first differential correction data packet at a fixed period, for example, each N information period is one fixed period, that is, the first and Nth information periods are all transmissions, and the remaining is an incremental dispatch. Optionally, the server end sends the first differential correction data irregularly, for example, the first information period is full transmission, the second and third information periods are incremental transmission, and the fourth information period is full transmission. , the 5th, 6th, and 7th information cycles are incremental transmissions, the 8th information cycle is full transmissions, the 9th, 10th, 11th, and 12th information cycles are incremental transmissions,... It can be sent by mail, etc.; For example, the first information cycle is a full dispatch, the second and third information cycles are incremental shipments, the fourth information cycle is a full shipment, and the fifth, sixth, seventh, eighth, and ninth information cycles. is an incremental dispatch, the 10th information cycle is a full transmission, the 11th, 12th, 13th, 14th, and 15th information cycles are an incremental transmission,... … It can be sent by, etc. Among the above-described first differential correction data packets, the A-bit (or total) quality factor data is sent regularly or irregularly, allowing the newly registered user terminal to obtain the raw quantity. Therefore, not only does it guarantee user precision, but it also guarantees a certain amount of information compression.

Optionally, the quality factor data of the B bit is an identifier indicating a change in the current quality factor data. For example, if the B bit is “1 bit”, where 1 bit is an identifier indicating the current quality factor data change and is 1 or 0, identifier 1 indicates decrease and identifier 0 indicates increase. In another embodiment, the quality factor data of the B bit in the second differential correction data packet is an increment of the current quality factor data.

Optionally, the system for transmitting the differential correction data packet includes a first receiving module and a calculating module. The first receiving module is used to receive state space indication method correction data sent from the satellite in each information period, and the calculation module performs encoding format calculation on the state space indication method correction data to generate a corresponding first difference. It is used to generate quality factor data among the correction data packets or quality factor data among the second difference correction data packets.

The first embodiment is a method embodiment corresponding to the present embodiment, so the technical details of the first embodiment can be applied to the present embodiment, and the technical details of the present embodiment can be applied to the first embodiment. You can.

The third embodiment of the present application relates to a method of receiving a differential correction data packet, the flow of which is as shown in FIG. 4, and the method of receiving a differential correction data packet includes the following steps.

In step 401, the user terminal receives the differential correction data packet sent from the server end.

Optionally, the differential correction data packet further includes satellite identification data, first, second, third and fourth model polynomial coefficient data (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ), wherein the first , the second, third and fourth model polynomial coefficient data correspond to one quality factor data (QI _A or QI _B ).

Next, moving to step 402, the user terminal determines whether the quality factor data received in the differential correction data packet is the A bit or the B bit, where A > B and A and B are positive integers.

Optionally, in step 402, the user terminal identifies whether the quality factor data is an A bit or a B bit according to the identification bit in the packet header of the differential correction data packet.

If the received quality factor data is A bit, the process moves to step 403 and updates the current quality factor data with the A bit quality factor data. For example, the current quality factor data can be directly replaced with A-bit quality factor data.

If the received quality factor data is B bit, the process goes to step 404, and the current quality factor data is updated according to the current quality factor data and the quality factor data of B bit. For example, the quality factor data of the B bit can be superimposed on the current quality factor data as an increment.

Optionally, the quality factor data of the A bits is total quality factor data, and the quality factor data of the B bits is incremental quality factor data.

There are several ways to set the quality factor data of the B bit. Optionally, the B bit quality factor data is an identifier indicating the current quality factor data change, and the user terminal uses a predetermined variable and the B bit received from the server end (for example, it may be 1 bit, where the 1 bit is An identifier indicating a change in the current quality factor data, which is either 1 or 0, with identifier 1 indicating a decrease and identifier 0 indicating an increase) of the current (e.g., last received) quality factor data (QI value). For absolute values, it is possible to choose to increase or decrease that absolute value according to a fixed amount predefined through the communication protocol. Optionally, the quality factor data in the B bit is an increment of the current quality indicator data.

What needs to be explained is that the method of receiving a differential correction data packet in the third embodiment of the present application may correspond to the method of transmitting a differential correction data packet in the first embodiment.

A fourth embodiment of the present application relates to a receiving system for differential correction data packets, the structure of which is as shown in Figure 5, and the receiving system for differential correction data packets includes a second receiving module, a decision module, and processing. Includes modules.

The second receiving module according to this embodiment is used to receive differential correction data packets from the server end.

Optionally, the differential correction data packet further includes satellite identification data, first, second, third and fourth model polynomial coefficient data (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ), where: The 1st, 2nd, 3rd and 4th model polynomial coefficient data correspond to one quality factor data (QI _A or QI _B ).

The decision module according to this embodiment determines whether the quality factor data received in the differential correction data packet is an A bit or a B bit, where A > B and A and B are positive integers.

Optionally, the determination module is used to identify whether the quality factor data is an A bit or a B bit, according to an identification bit in a packet header of the differential correction data packet.

Optionally, the A bits of quality factor data (QI _A ) are total quality factor data and the B bits of quality factor data (QI _B ) are incremental quality factor data.

Optionally, the B-bit quality factor data is an identifier indicating a current quality factor data change, or the B-bit quality factor data is an increment of the current quality factor data.

The processing module according to the present embodiment is used to update the current quality factor data with A-bit quality factor data when the received quality factor data is A-bit, for example, the current quality factor data is used to update the current quality factor data with A-bit quality factor data. can be directly replaced with, and also, when the received quality factor data is B bit, it is used to update the current quality factor data according to the current quality factor data and the quality factor data of B bit, for example, the quality factor of B bit Factor data can be incrementally overlaid on the current quality factor data, resulting in updated quality factor data.

Optionally, the B bit quality factor data is an identifier indicating the current quality factor data change, and the user terminal uses a predetermined variable and the B bit received from the server end (for example, it may be 1 bit, where the 1 bit is An identifier indicating a change in the current quality factor data, which is either 1 or 0, with identifier 1 indicating a decrease and identifier 0 indicating an increase) of the current (e.g., last received) quality factor data (QI value). For absolute values, it is possible to choose to increase or decrease that absolute value according to a fixed amount predefined through the communication protocol. Optionally, the B bit of quality factor data is an increment of the current quality indicator data.

The third embodiment is an embodiment of a method corresponding to the present embodiment, technical details in the third embodiment can be applied to the present embodiment, and technical details in the present embodiment can be applied to the third embodiment. .

Hereinafter, some related technologies according to embodiments of the present application will be briefly described.

The transmission and/or reception of differential correction data packets herein is based on the RTCM standard packet format, referring to the format orchestration of the Japanese QZSS system (see webpages 3 and 4), and is compatible with the existing and available GNSS systems. Targeted orchestration and compression were performed on the modified data.

The GPS differential protocol and the algorithm of differential messages are two issues that the differential system must consider. In the differential positioning application system, many differential messages are transmitted between the positioning terminal and the differential station, and the positioning terminal is a high-speed moving target, so to establish a data channel between the positioning terminal and the differential station, the traditional method is wireless communication. (e.g. short wave or ultra-high frequency), the lower interface generally uses a serial port (RS232/422), and both sides communicate in bytes, adapting to this communication method while maintaining high efficiency and the basics of error control. To realize the requirements, the RTCM 10403.2 standard has been established internationally. With the constant development of communication means, between the positioning terminal and the differential station, a large number of network methods are used to establish data links, and the data in network communication performs interaction according to the data package, and errors are effectively controlled at the data link layer. In order to adapt to the characteristics of network transmission, low-cost, low-error, high-efficiency, high-speed network communication is bringing new development opportunities to the application of differential positioning. In order to adapt to the characteristics of network transmission, the RTCM 10403.1 standard has been established internationally, and the network is currently the main means. I'm doing it.

The RTCM protocol specification includes application layer, presentation layer, transport layer, data link layer, and physical layer. The most important thing in encoding/decoding is orchestration of the physical layer. In the orchestration of the physical layer, the amount of data has a direct and significant impact on the total amount of information transfer within a unit of time. In situations where network connection is not possible, the mainstream method is to obtain calibration data by receiving satellite signals. The most important factor is how to complete transmission quickly and effectively within limited satellite transmission speed/time.

In PPP-RTK integrated positioning technology, information is divided into three layers: SSR1, SSR2, and SSR3. Here, SSR1 contains the following correction quantity types: orbit-4068.2, clock difference-4068.3, and code deviation-4068.4. SSR2 includes a correction quantity type called Phase Deviation-4068.5, Global Ionospheric Correction Quantity (VTEC). SSR3 includes correction quantity types called zonal atmospheric correction quantities (domain ionospheric STEC-4068.8, zonal ionospheric residual error RC-4068.9, and zonal atmospheric correction Tropo-4068.9). The name and transmission interval information of the SSR information format transmitted based on the satellite are shown in Table 1 below.

This application mainly optimizes by orchestrating field contents among the SSR information (including SSR1, SSR2, and SSR3) of the differential correction data packet. RTCM encoding and compact SSR encoding of QZSS correspond to one effective area (Network), which basically corresponds to a range of 100km * 100km per network, that is, one network = 10,000km² area. The existing encoding format data is calculated as shown in Table 2.

As can be seen from Table 2 above, in conventional coding, for each visible satellite of a GNSS system (GPS, GLONASS, Galileo, BeiDou, QZSS, etc.), there are four corresponding coefficients (C ₀₀ , C ₀₁ , C ₁₀ , C ₁₁ ) and one quality factor (Quality Indicator-QI) corresponding to four coefficients must be transmitted. For each transmission, the typical data amount of the corresponding SSR information is 6 bits. Based on China's 9.6 million km², the number of networks is 960 (referring to the unit area of 100km*100km as mentioned above), and the amount of transmission of the message per time is am. The 6 bits go through the following conversion formula (1).

Therefore, a mapping table similar to the SSR QI conversion table in Table 3 can be obtained.

According to binary encoding, 3 bits of data can represent 8 states from 000 to 111. Since Class and Value are each 3 bits, there are a total of 8*8=64 combinations, and the specific value of SSR QI can be obtained through conversion.

However, if one QI value is required for each 4068 type of message, the total data volume increases significantly, putting pressure on the channel. If calculated with messages from 4068.1-4068.10, if each message has a QI value of 6 bits for each satellite, the total QI value is as follows.

Compared to the content of a single message type, the amount of data is very large. Calculating accordingly, the demand for satellite communication resources (speeds are typically 1200bits to 2400bits per second) is very high. 4068 The specificity of information is that the data itself has a certain effectiveness, so the longer the interval, the less effective the correction is. The fixed compression format significantly improves the positioning results of the entire satellite.

In order to provide a better understanding of the technical means of the present application, they are described below in combination with specific examples. The details listed in the example are mainly for ease of understanding and should not be considered a limitation on the scope of protection herein.

Each embodiment herein applies to the northern region of China. Orchestration in the North can take the following forms of expression:

In the northern region, the variation in the SSR information range within the differential correction data message is relatively small, for example (2.5TECU to 2.45TECU every 30s), so when transmitting the first time, the Class and Value values of all 6 bits are transmitted. Send, and then only the increments (plus-minus change value) are sent, not the whole. It is the same as the new orchestration example of SSR information in Table 4 below.

Compared to Table 2, Table 4 adds 6 bits or 1 bit to choose from, and the user terminal uses predetermined variables and bits received from the server (identifier 1 indicates a decrease, identifier 0 indicates an increase). Accordingly, with respect to the absolute value of the last received QI value, it is possible to select an increase or decrease in the absolute value according to a fixed amount predefined through a communication protocol. The absolute value of 6 bits is sent uniformly in any fixed cycle (for example, 10 information cycles are considered as one fixed transmission cycle, that is, all are sent in the 1st and 10th times, and the remaining sends a 1-bit optimized format), allowing terminals newly subscribed to the service to obtain the raw amount. Therefore, not only can the user's user precision be guaranteed, but also a certain amount of information compression can be guaranteed, and the amount of data after compression is as follows.

The 1,356,000 bits were reduced by about one-third compared to the previous data amount of 4,608,000 bits. Today, when satellite communications are so precious and expensive, the benefits of saved resources go without saying.

In this specification, web page 1, web page 2, web page 3, and web page 4 are specifically as follows.

Web page 1: http://www.rtcm.org/differential-global-navigation-satellite--dgnss--standards.html;

Web page 2: http://qzss.go.jp/en/technical/download/pdf/ps-is-qzss/is-qzss-l6-001.pdf;

Web page 3: http://qzss.go.jp/en/technical/download/pdf/ps-is-qzss/is-qzss-l6-001.pdf;

Web page 4: http://qzss.go.jp/en/technical/ps-is-qzss/ps-is-qzss.html.

What needs to be explained is that, as anyone in the industry can understand, the implementation function of each module shown in the embodiment of the differential correction data packet reception system or transmission system described above is related to the differential correction data packet reception system or transmission method described above. You can understand by referring to the explanation. The functions of each module shown in the embodiment of the above-described differential correction data packet reception system or transmission system may be implemented through a program (executable instructions) running on a processor or through a specific logic circuit. When the above-described receiving system or transmitting system of the differential correction data packet of the embodiment of the present application is implemented in the form of a software function module and sold or used as an independent product, it may be stored in a computer-readable storage medium. Based on this understanding, the parts that are essential in the technical means of the embodiments of the present application or that contribute to existing technology may be expressed in the form of a software product, and the computer software product is stored in a storage medium and is stored in a computer device (personal computer, server, network device, etc.) may include several instructions that cause all or part of the method described in each embodiment of the present application to be executed. The above-described storage media includes various media capable of storing program code, such as USB memory, removable hard drives, read only memory (ROM), platters, or disks. As such, embodiments herein are not limited to any particular combination of hardware and software.

Accordingly, the embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, and the computer-executable instructions, when executed by a processor, implement each method embodiment of the first embodiment of the present application. Alternatively, each method embodiment in the third embodiment of the present application is implemented. Computer-readable storage media can store information in any method or technology, both permanent and non-permanent, removable and non-removable. The information may be instructions, data structures, modules of a program, or other data that can be read by a computer. Examples of computer storage media include phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), and other types of random access memory (Random Access Memory). RAM, Read Only Memory (ROM), Electronic Erasure Programmable Random Memory (EEPROM), flash memory, or other memory technologies, and Control Disc Random Memory (CD-ROM). stores information that can be accessed by a computer device, including, but not limited to, Digital Multiple Disc (DVD) or other optical memory, magnetic tape cassettes, magnetic disk storage or other magnetic storage devices, or other non-transmission media; It is used to As defined herein, computer-readable storage media does not include computer-readable transitory media, such as modulated data signals and carrier waves.

In addition, the embodiment of the present application further provides a transmission device for differential correction data packets including a memory for storing computer-executable instructions and a processor, wherein the processor executes the computer-executable instructions in the memory, and performs the first embodiment described above. The form is used to implement a step during each method embodiment. Among them, the processor may be a central processing unit (abbreviated as “CPU”), other general-purpose processors, digital signal processors (abbreviated as “DSP”), and application specific integrated circuits (Application Specific Integrated Circuits). , abbreviated as “ASIC”). The aforementioned memory may be read-only memory (abbreviated as “ROM”), random access memory (abbreviated as “RAM”), flash memory, hard drive, or solid state drive. there is. The steps of the method disclosed in each embodiment of the present invention may be performed directly by a hardware processor or may be implemented by combining hardware and software modules of the processor.

The embodiment of the present application further provides a differential correction data packet receiving device including a memory storing computer-executable instructions and a processor, wherein the processor executes the computer-executable instructions of the memory, and performs each of the above-described first embodiments. Methods are used to implement the steps of the embodiments. The processor may be a Central Processing Unit (abbreviated as “CPU”), another general-purpose processor, a Digital Signal Processor (abbreviated as “DSP”), or an Application Specific Integrated Circuit (ASIC). It may be abbreviated as ". The aforementioned memory may be read-only memory (abbreviated as “ROM”), random access memory (abbreviated as “RAM”), flash memory, hard drive, or solid state drive. there is. The steps of the method disclosed in each embodiment of the present invention may be performed directly by a hardware processor or may be implemented by combining hardware and software modules of the processor.

What needs to be explained is that in the application documents for this patent, relational terms such as first, second, etc. are merely intended to distinguish one entity or operation from another entity or operation, and no actual relationship exists between such entities or operations. or does not require or imply that order exists. Additionally, the terms “comprise,” “have,” “have,” or any other variation are intended to cover a non-exclusive inclusion, such that a process, method, article, or equipment comprising a set of elements is specified as well as those elements. Include other elements not included in the process, or elements inherent in the process, method, article or equipment. Without further limitation, elements defined by the phrase “including one” do not exclude the presence of other identical elements in any process, method, article or equipment that includes the described element. In the application documents for this patent, if it refers to performing an act based on an element, it means performing the act at least based on that element, including: performing the act only based on that element; , and includes two cases of performing the action based on that element and other elements. Expressions such as plural numbers, plural times, plural types, etc. include two, two times, two types, and two or more, two or more times, and two or more types.

All documents mentioned herein are collectively considered to be included in the disclosure of the present application, and may be used as a basis for amendments if necessary. In addition, it should be understood that the above description is only a better embodiment of the present specification and is not intended to limit the scope of protection of the present specification. All modifications, substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present specification shall be included within the scope of protection of one or more embodiments of the present specification.

Claims (24)

In a method of transmitting a differential correction data packet,
A server end sending a first differential correction data packet to a user terminal in a first information period, wherein the number of bits occupied by quality factor data in the first differential correction data packet is A;
In at least one consecutive information period after the first information period, the server end sends a second differential correction data packet to the user terminal, wherein the bit occupied by the quality factor data in the second differential correction data packet The number is B, where A > B and A and B are positive integers. According to paragraph 1,
A method of transmitting a differential correction data packet, characterized in that the packet header of the differential correction data packet includes an identification bit indicating whether the number of bits occupied by quality factor data in the packet is A bit or B bit. According to paragraph 1,
The first difference correction data packet further includes satellite identification data, first, second, third, and fourth model polynomial coefficient data, wherein the quality factor data in the first difference correction data packet is the first difference correction data. Corresponds to the first, second, third and fourth model polynomial coefficient data among the correction data packets,
The second difference correction data packet further includes satellite identification data, first, second, third, and fourth model polynomial coefficient data, wherein the quality factor data in the second difference correction data packet is the second difference correction data. A method of transmitting a differential correction data packet, characterized in that it corresponds to first, second, third, and fourth model polynomial coefficient data among the correction data packets. According to paragraph 1,
The quality factor data in the first differential correction data packet is total quality factor data, and the quality factor data in the second differential correction data packet is incremental quality factor data. According to paragraph 1,
A method of transmitting a differential correction data packet, characterized in that the quality factor data in the second differential correction data packet is an increment of the current quality factor data. According to paragraph 1,
Before the server end sends the first differential correction data packet to the user terminal in the first information period,
the server end receiving state space display method correction data sent from a satellite in each information period;
The server end performing encoding format calculation on the state space display method correction data to generate quality factor data among the corresponding first difference correction data packets or quality factor data among the second difference correction data packets; A method of transmitting a differential correction data packet, further comprising: In a transmission system for differential correction data packets,
A first transmission module configured to send a first differential correction data packet to the user terminal in a first information period, and to send a second differential correction data packet to the user terminal in at least one successive information period after the first information period. Includes,
Here, the number of bits occupied by the quality factor data in the first differential correction data packet is A, the number of bits occupied by the quality factor data in the second differential correction data packet is B, A > B, and A and B are positive integers. A transmission system for differential correction data packets, characterized in that: In clause 7,
A transmission system for a differential correction data packet, characterized in that the packet header of the differential correction data packet includes an identification bit indicating whether the number of bits occupied by quality factor data in the packet is A bit or B bit. In clause 7,
The first difference correction data packet further includes satellite identification data, first, second, third, and fourth model polynomial coefficient data, wherein the quality factor data in the first difference correction data packet is the first difference correction data. Corresponds to the first, second, third and fourth model polynomial coefficient data among the correction data packets,
The second difference correction data packet further includes satellite identification data, first, second, third, and fourth model polynomial coefficient data, wherein the quality factor data in the second difference correction data packet is the second difference correction data. A transmission system for differential correction data packets, characterized in that the correction data packets correspond to first, second, third and fourth model polynomial coefficient data. In clause 7,
A transmission system for a differential correction data packet, characterized in that the quality factor data in the first differential correction data packet is total quality factor data, and the quality factor data in the second differential correction data packet is incremental quality factor data. In clause 7,
A transmission system for a differential correction data packet, characterized in that the quality factor data in the second differential correction data packet is an increment of the current quality factor data. According to any one of claims 7 to 11,
Further comprising a first receiving module and a calculating module,
The first receiving module is used to receive state space indication method correction data sent from the satellite in each information period,
The calculation module is used to perform encoding format calculation on the state space representation method correction data to generate corresponding quality factor data among the first difference correction data packet or quality factor data among the second difference correction data packet. A transmission system for differential correction data packets, characterized in that: In a method of receiving a differential correction data packet,
A user terminal receiving a differential correction data packet sent from the server end;
determining, by the user terminal, whether the quality factor data received in the differential correction data packet is an A bit or a B bit, where A > B and A and B are positive integers;
If the received quality factor data is A bit, updating the current quality factor data with the A bit quality factor data;
When the received quality factor data is B bit, updating the quality factor data according to the current quality factor data and the B bit quality factor data. A method of receiving a differential correction data packet, comprising: . According to clause 13,
In the step of the user terminal determining whether the received quality factor data in the differential correction data packet is an A bit or a B bit,
The method of receiving a differential correction data packet, characterized in that the user terminal identifies whether the quality factor data is an A bit or a B bit according to an identification bit in the packet header of the differential correction data packet. According to clause 13,
A method of receiving a differential correction data packet, characterized in that the quality factor data of the A bit is total quality factor data, and the quality factor data of the B bit is incremental quality factor data. According to clause 13,
The method of receiving a differential correction data packet, characterized in that the quality factor data of the B bit is an increment of the current quality factor data. In a system for receiving differential correction data packets,
a second receiving module that receives a differential correction data packet from the server end;
a decision module that determines whether the received quality factor data among the differential correction data packets is an A bit or a B bit;
If the received quality factor data is A bit, the current quality factor data is updated with the A bit quality factor data, and if the received quality factor data is B bit, the current quality factor data and the B bit quality factor are updated. A processing module that updates the current quality factor data according to data,
wherein A > B and A and B are positive integers. According to clause 17,
The determination module is further used to identify whether the quality factor data is an A bit or a B bit, according to an identification bit in the packet header of the differential correction data packet. . According to clause 17,
A receiving system for a differential correction data packet, characterized in that the quality factor data of the A bit is total quality factor data, and the quality factor data of the B bit is incremental quality factor data. According to any one of claims 17 to 19,
The system for receiving differential correction data packets, wherein the quality factor data of the B bits is an increment of the current quality factor data. In a transmitting device for differential correction data packets,
a memory that stores instructions executable on the computer;
A processor that implements the steps of the method of any one of claims 1 to 6 when executing instructions executable on the computer. In a computer-readable storage medium,
The computer-readable storage medium stores instructions executable on a computer,
A computer-readable storage medium, characterized in that implementing the steps of the method of any one of claims 1 to 6 when the computer-executable instructions are executed by a processor. In the receiving device for differential correction data packets,
a memory that stores instructions executable on the computer;
A receiving device for differential correction data packets, comprising a processor that implements the steps of the method of any one of claims 13 to 16 when executing instructions executable on the computer. In a computer-readable storage medium,
The computer-readable storage medium stores instructions executable on a computer,
A computer-readable storage medium, characterized in that implementing the steps of the method of any one of claims 13 to 16 when the computer-executable instructions are executed by a processor.

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