A method and system for adaptively coded RDSS baseband transmission

Abstract

The present invention discloses an adaptively coded RDSS baseband transmission method and system. The method includes, when a message communication instruction is obtained, reading the message data to be sent from the RAM under clock drive; dividing the message data into a first segment of data and a second segment of data; obtaining a satellite beam state that can send a short message signal; adaptively encoding the second segment of data in the message data according to the satellite beam state that can send a short message signal; obtaining an inbound type, and performing secondary encoding on the adaptively coded message data according to the inbound type; outputting the secondary coded message data through a multiplexer and spread spectrum modulation, and then outputting a baseband BPSK signal. The solution provided by the present invention can realize the reliable transmission of RDSS baseband BPSK signals in different complex environments, and improve the transmission efficiency when the channel conditions are good.

Description

Technical Field

[0001] The present invention relates to the field of Beidou RDSS technology, and in particular to an adaptively coded RDSS baseband transmission method and system. Background Art

[0002] The RDSS short message communication system consists of four parts: the sending terminal, GEO satellite, ground center station, and receiver terminal. The sending terminal sends the short message information to the GEO satellite through the L-band channel, which is converted into a C-band signal through the L / C transparent transponder on the satellite and sent to the ground center station. The ground center station then verifies the received signal and information. If the conditions are met, it is sent to the GEO satellite through the C-band uplink channel. The GEO satellite then sends it to the target receiving terminal through the C / S transparent transponder, completing the transmission of the short message information.

[0003] Convolutional codes and Turbo codes are used as channel coding schemes in the system signals of Beidou RDSS services to resist the effects of multipath fading, burst noise, etc. encountered by the signal during transmission. Convolutional code is a linear non-block code suitable for forward error correction. Convolutional code is represented by (n, k, N), and the coding rule is to generate n code elements by inputting k code elements in any specified period of time. It depends not only on the N information bits in this period of time, but also on the information bits in the previous (N-1) specified period of time. The parameter N is the constraint length of the convolutional code, and the number of shift registers m=N-1. Turbo code is an interleaved convolutional code that obtains a greater interleaving gain by feeding back the convolutional code. The performance of Turbo code mainly depends on its effective free distance. It has a near-Shannon bound error correction capability at a medium signal-to-noise ratio, so it has superior performance in a high-noise environment with a low signal-to-noise ratio and has strong anti-fading and anti-interference capabilities. Turbo code can correct bit errors that occur during high-speed data transmission. The use of Turbo code technology in direct spread (CDMA) systems can further improve the capacity of the system.

[0004] The Beidou RDSS channel is a typical fading channel. Considering the time-varying characteristics of channel fading, a fixed, single coding and modulation scheme cannot fully utilize the bandwidth when the channel conditions are good, and may not guarantee data transmission when the channel conditions are very poor. The current Beidou RDSS user inbound system adopts a transmission system with fixed modulation and coding methods, but its signal is easily affected by factors such as weather fading, shadow fading, and multipath effects, resulting in reduced transmission reliability. At the same time, Turbo code encoding has very good error correction performance in codeword transmission with relatively low bit rates, but the low bit rate also means that the frequency band utilization of Turbo code is relatively low, making it difficult to be compatible with high-performance and anti-interference application environments. Summary of the invention

[0005] In order to solve the technical problem that the current fixed and single coding and modulation scheme cannot fully utilize the bandwidth when the channel conditions are good, and may not be able to guarantee data transmission when the channel conditions are very poor, the embodiment of the present invention provides an adaptively coded RDSS baseband transmission method and system.

[0006] The technical solution of the embodiment of the present invention is achieved as follows:

[0007] An embodiment of the present invention provides an adaptively coded RDSS baseband transmission method, the method comprising: when a message communication instruction is obtained, reading the telegram data to be sent from the RAM under clock drive; dividing the telegram data into a first segment of data and a second segment of data; obtaining a satellite beam state that can send a short message signal; adaptively encoding the second segment of data in the telegram data according to the satellite beam state that can send the short message signal; obtaining an inbound type, and performing secondary encoding on the adaptively coded telegram data according to the inbound type; outputting the secondary coded telegram data through a multiplexer selection and spread spectrum modulation, and then outputting a baseband BPSK signal.

[0008] In one embodiment, the telegram data is divided into a first segment of data and a second segment of data, including: dividing a synchronization header segment and a service segment in the telegram data into the first segment of data, and dividing a data segment in the telegram data into the second segment of data.

[0009] In one embodiment, the part that needs to be encoded in the telegram data is adaptively encoded according to the satellite beam state that can send short message signals, including: when the service type of the telegram data is the BeiDou-2 RDSS short message sending task, the part that needs to be encoded in the telegram data is adaptively encoded in the following manner according to the satellite beam state that can send short message signals: when the maximum speed is less than or equal to a first threshold, and the maximum acceleration is less than or equal to a second threshold, and the jerk is less than or equal to a third threshold, and the elevation angle is greater than a fourth threshold and less than 90°, the part that needs to be encoded is encoded using an LDPC encoding method; when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than a fifth threshold and less than or equal to the fourth threshold, the part that needs to be encoded is encoded using an LDPC encoding method. A turbo coding method is adopted; when the maximum speed is less than or equal to a first threshold, and the maximum acceleration is less than or equal to a second threshold, and the jerk is less than or equal to a third threshold, and the elevation angle is greater than 0° and less than or equal to a fifth threshold, and the second segment of data is less than two-thirds of the maximum transmittable data length, a turbo coding method is adopted for the portion that needs to be encoded; when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is greater than or equal to two-thirds of the maximum transmittable data length, an LDPC coding method is adopted for the portion that needs to be encoded; when the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, encoding is not performed on the portion that needs to be encoded.

[0010] In one embodiment, the part of the telegram data that needs to be encoded is adaptively encoded according to the state of the satellite beam that can send the short message signal, including: when the service type of the telegram data is the BeiDou-3 RDSS short message sending task, the part of the telegram data that needs to be encoded is adaptively encoded in the following manner according to the state of the satellite beam that can send the short message signal: when the maximum speed is less than or equal to a first threshold, and the maximum acceleration is less than or equal to a second threshold, and the jerk is less than or equal to a third threshold, and the elevation angle is greater than a fourth threshold and less than 90°, convolution encoding is used for the part that needs to be encoded; when the maximum speed is less than or equal to a first threshold, and the maximum acceleration is less than or equal to a second threshold, and the jerk is less than or equal to a third threshold, and the elevation angle is greater than a fourth threshold and less than 90°, convolution encoding is used for the part that needs to be encoded; When the maximum speed is equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, the LDPC encoding method is used for the part that needs to be encoded; when the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than 0° and less than or equal to the fifth threshold, the LDPC encoding method is used for the part that needs to be encoded; when the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, convolution encoding is used for the part that needs to be encoded.

[0011] In one embodiment, the adaptively encoded telegram data is secondary encoded according to the inbound type, including: when the inbound type is BeiDou-2, the secondary encoding method is convolutional encoding; when the inbound type is BeiDou-3, the secondary encoding method is turbo encoding.

[0012] An embodiment of the present invention provides an adaptively coded RDSS baseband transmission system, the system comprising a telegram acquisition module, a coding module, and a modulation module: the telegram acquisition module is used to read the telegram data to be sent from the RAM under clock drive when the message communication instruction is acquired; the telegram data is divided into a first segment of data and a second segment of data; the coding module is used to acquire the satellite beam state that can send a short message signal; adaptively encode the second segment of data in the telegram data according to the satellite beam state that can send the short message signal; acquire the inbound type, and perform secondary encoding on the adaptively coded telegram data according to the inbound type; the modulation module is used to output the baseband BPSK signal after the secondary coded telegram data is selected and output by a multiplexer and spread spectrum modulated.

[0013] In one embodiment, the telegram acquisition module is further specifically used to divide the synchronization header segment and the service segment in the telegram data into the first segment data, and divide the data segment in the telegram data into the second segment data.

[0014] In one embodiment, the encoding module is further specifically used to adaptively encode the part that needs to be encoded in the telegram data in the following manner according to the satellite beam state that can send the short message signal when the service type of the telegram data is the BeiDou-2 RDSS short message sending task: when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, the LDPC encoding method is used for the part that needs to be encoded; when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, the turbo encoding method is used for the part that needs to be encoded; when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, the turbo encoding method is used for the part that needs to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is less than two-thirds of the maximum transmittable data length, turbo coding is adopted for the portion that needs to be encoded; when the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is greater than or equal to two-thirds of the maximum transmittable data length, LDPC coding is adopted for the portion that needs to be encoded; when the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, no encoding is performed on the portion that needs to be encoded.

[0015] In one embodiment, the encoding module is further specifically used to adaptively encode the part that needs to be encoded in the telegram data in the following manner according to the satellite beam state that can send the short message signal when the service type of the telegram data is the Beidou-3 RDSS short message sending task: when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, use convolution coding for the part that needs to be encoded; when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°. When the maximum speed is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, the LDPC encoding method is used for the part that needs to be encoded; when the maximum speed is less than or equal to the first threshold, and the maximum acceleration is less than or equal to the second threshold, and the jerk is less than or equal to the third threshold, and the elevation angle is greater than 0° and less than or equal to the fifth threshold, the LDPC encoding method is used for the part that needs to be encoded; when the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, convolution encoding is used for the part that needs to be encoded.

[0016] In one embodiment, the encoding module is further specifically used to use convolutional coding as the secondary encoding method when the inbound type is BeiDou-2; and turbo coding as the secondary encoding method when the inbound type is BeiDou-3.

[0017] The solution provided by the present invention has the following beneficial effects:

[0018] (1) Perform two encodings based on the service type, satellite beam status, and inbound type to increase signal gain and thereby improve outbound sensitivity.

[0019] (2) While ensuring a certain transmission quality, the coding method can be switched according to the satellite beam status, service type, etc., to adapt to application environments in different dynamic and interference environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flowchart of the RDSS baseband transmission method of adaptive coding according to an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the application flow of the adaptively coded RDSS baseband transmission method according to an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the structure of the RDSS baseband transmission system with adaptive coding according to an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of the processing relationship of the adaptively coded RDSS baseband transmission system according to an embodiment of the present invention;

[0024] Figure 5 The figure is a diagram showing the internal structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

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

[0026] The embodiment of the present invention provides an adaptively coded RDSS baseband transmission method, such as Figure 1 As shown, the method includes:

[0027] Step 101: when a message communication instruction is obtained, the message data to be sent is read from the RAM under the clock drive; the message data is divided into a first segment of data and a second segment of data;

[0028] Step 102: Acquire a satellite beam state capable of sending a short message signal; and adaptively encode the second segment of data in the telegram data according to the satellite beam state capable of sending a short message signal;

[0029] Step 103: obtaining an inbound type, and performing secondary encoding on the adaptively encoded electronic message data according to the inbound type;

[0030] Step 104: The secondary-encoded telegram data is selected and output by a multiplexer and spread spectrum modulated to output a baseband BPSK signal.

[0031] This embodiment completes the coding modulation of the RDSS baseband BPSK signal based on secondary coding, realizes reliable transmission in different complex environments, and improves transmission efficiency when the channel condition is good. By adaptively coding the data, high performance and anti-interference are achieved.

[0032] Specifically, the telegram data may be divided in the following manner: the synchronization header segment and the service segment in the telegram data are divided into the first segment data, and the data segment in the telegram data is divided into the second segment data.

[0033] Here, the division method can also be adjusted according to actual conditions. For example, the synchronization header and the service segment in the telegram data that do not need to be encoded can be divided into the first segment of data, the service segment that needs to be encoded can be divided into the second segment of data, and the data segment can be divided into the third segment of data.

[0034] In addition, when performing adaptive coding, different coding methods can be adaptively executed according to different scenarios.

[0035] Specifically, when the service type of the telegram data is a BeiDou-2 RDSS short message sending task, the part to be encoded in the telegram data is adaptively encoded in the following manner according to the satellite beam state that can send the short message signal:

[0036] When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, the LDPC encoding method is used for the part that needs to be encoded;

[0037] When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, turbo encoding is used for the portion to be encoded;

[0038] When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is less than two-thirds of the maximum transmittable data length, turbo encoding is used for the portion to be encoded;

[0039] When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is greater than or equal to two-thirds of the maximum transmittable data length, the LDPC encoding method is used for the portion to be encoded;

[0040] When the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, encoding is not performed on the portion requiring encoding.

[0041] Correspondingly, when the service type of the telegram data is the BeiDou-3 RDSS short message sending task, the part to be encoded in the telegram data is adaptively encoded in the following manner according to the satellite beam state that can send the short message signal:

[0042] When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, convolution coding is applied to the portion to be coded;

[0043] When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, the LDPC encoding method is used for the part that needs to be encoded;

[0044] When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than 0° and less than or equal to the fifth threshold, the LDPC encoding method is used for the part that needs to be encoded;

[0045] When the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, convolution coding is applied to the portion requiring coding.

[0046] In actual application, the first threshold, the second threshold, the third threshold, the fourth threshold and the fifth threshold can be set according to actual conditions. For example, the first threshold can be set to 515m / s, the second threshold can be set to 4g, and the third threshold can be set to 0.4g / s.

[0047] In addition, when the service type of the telegram data is BeiDou-2 RDSS short message transmission, the elevation angle can be divided into three different sub-areas, and the beam angle range corresponding to each area is divided into 0~5th threshold , the fifth threshold ~The fourth threshold , the fifth threshold ~90°, and different encoding schemes are implemented in the corresponding area in combination with the signal-to-noise ratio and dynamic range.

[0048] In addition, in one embodiment, the adaptively encoded telegram data is secondary encoded according to the inbound type, which can be specifically: when the inbound type is BeiDou-2, the secondary encoding method is convolutional encoding; when the inbound type is BeiDou-3, the secondary encoding method is turbo encoding.

[0049] The solution provided by the present invention can realize the reliable transmission of RDSS baseband BPSK signals in different complex environments and improve the transmission efficiency when the channel condition is good.

[0050] Below, the solution of the present invention will be described in detail based on a specific embodiment.

[0051] This embodiment first obtains the current outbound signal status information, adaptively encodes the data according to the application environment status, service characteristics and other information, then performs secondary encoding according to the inbound signal requirements, and finally performs spread spectrum modulation to output the baseband BPSK signal, thereby improving the environmental adaptability of the signal and having strong adaptability. Figure 2 , this embodiment scheme specifically includes the following contents:

[0052] S1. When receiving the message communication instruction, the message data (synchronization header, service segment and data segment) to be sent is read from the RAM under the clock drive, and the data is divided into two segments, where the synchronization header and service segment are the first segment x1, and the data segment is the second segment x2. The segmentation can be adjusted according to the actual application;

[0053] S2. Synchronously obtain the outbound signal capture and tracking status, detect the Beidou RDSS satellite signal reception status, and obtain the satellite beam status that can send short message signals, including signal-to-noise ratio, elevation and azimuth angles, dynamic information, etc.;

[0054] S3. Set the flags of no coding, LDPC coding, turbo coding, and convolution coding to 000, 001, 010, and 011 respectively, and comprehensively select the coding method and perform coding in the following manner.

[0055] When sending BeiDou-2 RDSS short messages, it is divided into the following scenarios:

[0056] The elevation angle is divided into three different sub-areas, and the beam angle range corresponding to each area is 0~ , ~ , ~90°, and different encoding schemes are implemented in the corresponding area in combination with the signal-to-noise ratio and dynamic range.

[0057] When sending a BeiDou-2 RDSS short message, it is executed in the following scenarios:

[0058] 1) When the dynamic range is small (such as maximum speed ≤ 515m / s, maximum acceleration ≤ 4g, jerk ≤ 0.4g / s), ~90°, when the signal-to-noise ratio is good, the data segment is LDPC coded;

[0059] 2) When the dynamic range is small, ~ ,When the signal-to-noise ratio is poor, the data segment is turbo-encoded;

[0060] 3) When the dynamic range is small, 0~ , the signal-to-noise ratio is poor. When the sent data segment is less than 2 / 3 of the maximum sendable data length, the data segment is turbo-encoded;

[0061] 4) When the dynamic range is small, 0~ , the signal-to-noise ratio is poor. When the transmitted data segment is ≥ 2 / 3 of the maximum transmittable data length, the data segment is LDPC encoded;

[0062] 5) When the dynamic range is large, such as medium and high dynamic scenes, the data segment is not encoded uniformly;

[0063] When sending a BeiDou-3 RDSS short message, it is executed in the following scenarios:

[0064] 1) When the dynamic range is small (such as maximum speed ≤ 515m / s, maximum acceleration ≤ 4g, jerk ≤ 0.4g / s), ~90°, when the signal-to-noise ratio is good, the data segment is convolutionally encoded;

[0065] 2) When the dynamic range is small, ~ ,When the signal-to-noise ratio is poor, the data segment is LDPC coded;

[0066] 3) When the dynamic range is small, 0~ ,When the signal-to-noise ratio is poor, the data segment is LDPC coded;

[0067] 4) When the dynamic range is large, such as in medium and high dynamic scenes, convolution coding is performed and Doppler compensation transmission is performed;

[0068] in , The value can be adjusted according to the actual application environment. When the application environment is in good condition, generally The value is larger.

[0069] LDPC coding uses variable coding, and uses different code rates for coding according to different signal-to-noise ratio ranges. Generally, 1 / 2 is used, and the variable code rates include 1 / 3, 2 / 3, and 3 / 4.

[0070] Encoded check matrix , calculate the generated matrix ,use Encode the input information sequence m of length k to obtain a codeword of length n, generating the matrix The generation method is as follows:

[0071] 1) Set the size to The matrix Expressed as ,in Size , Size ;

[0072] 2) The matrix Converted into system form, Left multiplication , and the right side is the check matrix of the unit matrix ,in for Unit array;

[0073] 3) Get the matrix ,in for Unit array.

[0074] S4. After the data encoded in S3 is completed, the identifier is inserted into the service segment. The message data is encoded again according to the corresponding inbound type through the interleaver. North II performs convolutional encoding, and North III performs turbo encoding. The output is selected by the multiplexer MUX, and the output result is the data content before spread spectrum modulation; when the read address exceeds the data bit, the transmission completion flag is fed back to the timing control module;

[0075] S5. When the start transmission signal is valid, the inbound signal spread spectrum code is generated under the drive of the code clock. The spread spectrum code rate of the inbound signal is 4.08MHz, and its actual frequency is achieved through the code NCO method; the spread spectrum code and data are XORed, and finally the baseband BPSK signal is output.

[0076] The technical effects are as follows:

[0077] (1) Perform two encodings based on service characteristics, channel status, and inbound signal requirements to increase signal gain and thereby improve outbound sensitivity.

[0078] (2) While ensuring a certain transmission quality, the coding method can be switched according to the channel status, service characteristics, etc., to adapt to application environments in different dynamic and interference environments.

[0079] In order to implement the method of the embodiment of the present invention, the embodiment of the present invention also provides an adaptively coded RDSS baseband transmission system, such as Figure 3 As shown, the adaptively coded RDSS baseband transmission system 300 includes: a message acquisition module 301, a coding module 302, and a modulation module 303;

[0080] The telegram acquisition module 301 is used to read the telegram data to be sent from the RAM under the clock drive when the message communication instruction is acquired; divide the telegram data into a first segment of data and a second segment of data;

[0081] The encoding module 302 is used to obtain the satellite beam state that can send short message signals; adaptively encode the second segment of the telegram data according to the satellite beam state that can send short message signals; obtain the inbound type, and perform secondary encoding on the adaptively encoded telegram data according to the inbound type;

[0082] The modulation module 303 is used to output the secondary encoded telegram data through a multiplexer for output selection and spread spectrum modulation, and then output a baseband BPSK signal.

[0083] In practical applications, the adaptively coded RDSS baseband transmission system may further include a spread spectrum code generation module. Figure 4 ,The system includes a spread spectrum code generation module, a message acquisition module, a coding module, and a modulation module.

[0084] The spread spectrum code generation module, driven by the code clock, generates a spread spectrum code sequence, and supports the generation of spread spectrum codes for the BeiDou-2 regional short message, BeiDou-3 regional short message, and BeiDou-3 global short message inbound signal systems;

[0085] The telegram acquisition module acquires the original telegram data to be sent stored in the RAM under the drive of the symbol rate clock;

[0086] The encoding module completes the telegram data encoding, including adaptive encoding methods and channel encoding required by the inbound signal, such as convolutional encoding, Turbo encoding, LDPC encoding, etc.; when the data does not need to be encoded, it is passed directly;

[0087] The modulation module, under the control of the spread spectrum code and symbol rate clock, completes BPSK modulation to generate a baseband output signal.

[0088] The above-mentioned system provided in this embodiment belongs to the same concept as the above-mentioned method embodiment. The specific implementation process thereof is detailed in the method embodiment and will not be repeated here.

[0089] In order to implement the method of the embodiment of the present invention, the embodiment of the present invention also provides a computer program product, which includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device performs the steps of the above method.

[0090] Based on the hardware implementation of the above program modules, and in order to implement the method of the embodiment of the present invention, the embodiment of the present invention further provides an electronic device (computer device). Specifically, in one embodiment, the computer device may be a terminal, and its internal structure diagram may be as follows: Figure 5 As shown. The computer device includes a processor A01, a network interface A02, a display screen A04, an input device A05 and a memory (not shown in the figure) connected through a system bus. Among them, the processor A01 of the computer device is used to provide computing and control capabilities. The memory of the computer device includes an internal memory A03 and a non-volatile storage medium A06. The non-volatile storage medium A06 stores an operating system B01 and a computer program B02. The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 in the non-volatile storage medium A06. The network interface A02 of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor A01, the method of any one of the above embodiments is implemented. The display screen A04 of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device A05 of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0091] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0092] The device provided by the embodiment of the present invention includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the method of any one of the above embodiments is implemented.

[0093] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0094] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0095] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0096] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0097] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0098] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0099] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0100] It can be understood that the memory of the embodiment of the present invention can be a volatile memory or a non-volatile memory, and can also include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory can be a disk memory or a tape memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM, SyncLink Dynamic Random Access Memory), and direct RAMbus random access memory (DRRAM, Direct Rambus Random Access Memory).The memories described in the embodiments of the present invention are intended to include, but are not limited to, these and any other suitable types of memories.

[0101] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0102] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. An adaptively coded RDSS baseband transmission method, characterized in that: The method comprises: When a message communication instruction is obtained, the message data to be sent is read from the RAM under the clock drive; the message data is divided into a first segment of data and a second segment of data; Acquire a satellite beam state capable of sending a short message signal; and adaptively encode the second segment of data in the telegram data according to the satellite beam state capable of sending a short message signal; Obtaining an inbound type, and performing secondary encoding on the adaptively encoded telegram data according to the inbound type; The secondary-encoded telegram data is selected and output by a multiplexer and spread-spectrum modulated to output a baseband BPSK signal; The step of adaptively encoding the part of the message data that needs to be encoded according to the state of the satellite beam that can send the short message signal includes: When the service type of the telegram data is a BeiDou-2 RDSS short message sending task, the part to be encoded in the telegram data is adaptively encoded in the following manner according to the satellite beam state that can send the short message signal: When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, the LDPC encoding method is used for the part that needs to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, turbo encoding is used for the portion to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is less than two-thirds of the maximum transmittable data length, turbo encoding is used for the portion to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is greater than or equal to two-thirds of the maximum transmittable data length, the LDPC encoding method is used for the portion to be encoded; When the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, encoding is not performed on the portion requiring encoding.

2. The adaptively coded RDSS baseband transmission method according to claim 1, characterized in that: Dividing the electronic message data into a first segment of data and a second segment of data includes: The synchronization header segment and the service segment in the telegram data are divided into the first segment of data, and the data segment in the telegram data is divided into the second segment of data.

3. The adaptively coded RDSS baseband transmission method according to claim 1, characterized in that: Adaptively encoding the part of the message data that needs to be encoded according to the state of the satellite beam that can send the short message signal, including: When the service type of the telegram data is a BeiDou-3 RDSS short message sending task, the part to be encoded in the telegram data is adaptively encoded in the following manner according to the satellite beam state that can send the short message signal: When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, convolution coding is applied to the portion to be coded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, the LDPC encoding method is used for the part that needs to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than 0° and less than or equal to the fifth threshold, the LDPC encoding method is used for the part that needs to be encoded; When the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, convolution coding is applied to the portion requiring coding.

4. The adaptively coded RDSS baseband transmission method according to claim 3, characterized in that: The adaptively encoded telegram data is re-encoded according to the inbound type, including: When the inbound type is BeiDou-2, the secondary encoding method is convolutional encoding; When the inbound type is BeiDou-3, the secondary encoding method is turbo encoding.

5. An adaptively coded RDSS baseband transmission system, characterized in that: The system includes a message acquisition module, a coding module, and a modulation module: The telegram acquisition module is used to read the telegram data to be sent from the RAM under the clock drive when the message communication instruction is acquired; and divide the telegram data into a first segment of data and a second segment of data; The encoding module is used to obtain the satellite beam state that can send the short message signal; according to the satellite beam state that can send the short message signal, the second segment of the data in the telegram data is adaptively encoded; Obtaining an inbound type, and performing secondary encoding on the adaptively encoded telegram data according to the inbound type; The modulation module is used to output the baseband BPSK signal after the secondary encoded telegram data is selected and output by a multiplexer and spread spectrum modulated; The encoding module is further specifically used to adaptively encode the part that needs to be encoded in the telegram data in the following manner according to the satellite beam state that can send short message signals when the service type of the telegram data is a BeiDou-2 RDSS short message sending task: When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, the LDPC encoding method is used for the part that needs to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, turbo encoding is used for the portion to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is less than two-thirds of the maximum transmittable data length, turbo encoding is used for the portion to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, the elevation angle is greater than 0° and less than or equal to the fifth threshold, and the second segment of data is greater than or equal to two-thirds of the maximum transmittable data length, the LDPC encoding method is used for the portion to be encoded; When the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, encoding is not performed on the portion requiring encoding.

6. The adaptively coded RDSS baseband transmission system according to claim 5, characterized in that: The telegram acquisition module is also specifically used to divide the synchronization header segment and the service segment in the telegram data into the first segment data, and divide the data segment in the telegram data into the second segment data.

7. The adaptively coded RDSS baseband transmission system according to claim 5, characterized in that: The encoding module is further specifically used to adaptively encode the part that needs to be encoded in the telegram data in the following manner according to the satellite beam state that can send short message signals when the service type of the telegram data is a BeiDou-3 RDSS short message sending task: When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fourth threshold and less than 90°, convolution coding is applied to the portion to be coded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than the fifth threshold and less than or equal to the fourth threshold, the LDPC encoding method is used for the part that needs to be encoded; When the maximum speed is less than or equal to the first threshold, the maximum acceleration is less than or equal to the second threshold, the jerk is less than or equal to the third threshold, and the elevation angle is greater than 0° and less than or equal to the fifth threshold, the LDPC encoding method is used for the part that needs to be encoded; When the maximum speed is greater than the first threshold, or the maximum acceleration is greater than the second threshold, or the jerk is greater than the third threshold, convolution coding is applied to the portion requiring coding.

8. The adaptively coded RDSS baseband transmission system according to claim 7, characterized in that: The encoding module is also specifically used for, when the inbound type is BeiDou-2, the secondary encoding method is convolutional encoding; when the inbound type is BeiDou-3, the secondary encoding method is turbo encoding.

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