GB/T 39348-2020 in English
VALIDSpace data and information transfer systems—TM (telemetry)synchronization and channel coding
- Issued on:2020-11-19
- Implemented on:2021-06-01
- File Format:PDF
- Delivery:Via email within 5 business days
$670.00
| Standard No: | GB/T 39348-2020 |
| Document status: | VALID |
| Title in English: | Space data and information transfer systems—TM (telemetry)synchronization and channel coding |
| Title in Chinese: | 空间数据与信息传输系统 遥测同步与信道编码 |
| Language: | English |
| File Format: | Electronic (PDF) |
| Delivery: | Via email within 5 business days |
| Issued on: | 2020-11-19 |
| Implemented on: | 2021-06-01 |
| ICS Classification: | 49.140-Space systems and operations |
| Chinese Classification: | V75-Spacecraft telemetering and remote sensing system |
| Professional Classification: | GB-National Standard |
| Related Topics: | remote
telemetry data channel coding channel coding GBT39348 GB/T 39348-2020 channel coding standard Information transfer Remote signaling test Agricultural spatial information standards and |
《GB/T 39348-2020空间数据与信息传输系统 遥测同步与信道编码》由TC425（全国宇航技术及其应用标准化技术委员会）归口，TC425SC3（全国宇航技术及其应用标准化技术委员会空间数据与信息传输分会）执行，主管部门为国家标准化管理委员会。
Introduction
Standard Overview
GB/T 39348-2020 specifies the technical requirements for telemetry synchronization and channel coding in space data and information transmission systems, and is applicable to the interface design of air-to-ground and air-to-air links. The standard covers the coding methods of convolutional codes, RS codes, Turbo codes and LDPC codes, as well as key technologies such as synchronization identification and pseudo-randomization.
Comparison of Core Coding Technologies
| Coding Type | Code Rate | Error Correction Capability | Applicable Scenarios |
|---|---|---|---|
| Convolutional Code | 1/2, 2/3, 3/4, 7/8 | Medium (constraint length k=7) | Gaussian noise channel, cascaded RS code enhanced error correction is required |
| RS(255,223) | 223/255 | Correct 16 symbol errors | Burst error channel, support interleaving depth I=1~8 |
| Turbo code | 1/2, 1/3, 1/4, 1/6 | High (long code block) | High coding gain requirement, requires frame check |
| LDPC code | 1/2, 2/3, 4/5, 223/255 | Extremely high (sparse check matrix) | Large-capacity data transmission, supports 1024~16384bit frame length |
Analysis of key technologies
1. Synchronization mechanism
The standard stipulates the use of Additional Synchronization Marker (ASM) to achieve frame synchronization:
- 32-bit ASM: 1ACFFC1D (hexadecimal), used for convolutional code/RS code/7/8 LDPC code;
- 64-bit ASM: 034776C7272895B0, used for 1/2 Turbo code and 1/2~4/5 LDPC code.
The synchronization marker needs to be directly inserted before the code block and does not participate in the encoding process.
2. Pseudo-randomization processing
To balance the bit transition density, the standard recommends using a 255-bit pseudo-random sequence with the generator polynomial h(x)=x8+x7+x5+x3+1 to perform an XOR operation on the RS code block, Turbo code word or transmission frame (except ASM).
Implementation Recommendations
Typical Application Cases
Deep Space Communication Link Design: When using cascade coding (RS outer code + convolutional inner code), please note:
- ASM is only inserted before convolutional coding;
- The virtual padding length must be fixed to an integer multiple of 8I bytes;
- When the interleaving depth I=5, the maximum logical code block length is 10200 bits.
Standard Evolution Analysis
Compared with ISO 22641:2012, the main technical differences of GB/T 39348-2020 include:
- Added detailed specifications for LDPC code clusters (code rates 1/2~4/5);
- Strengthened the description of the permutation algorithm of the Turbo code interleaver;
- Optimized the pseudo-randomization synchronization process and clarified the association with ASM.
Loading PDF document...
Error loading PDF. Please make sure the file is valid and try again.
We also recommend
-
GB/T 46525-2025 in English
Space data and information transfer systems—Spacecraft information system service and protocol architecture
2025-10-31 -
GB/T 42038-2022 in English
Space data and information transfer systems—File delivery protocol
2022-10-12
