Space data and information transfer systems — CCSDS Space Link Protocols over ETSI DVB-S2 Standard
空间数据和信息传输系统 - 通过ETSI DVB-S2标准的CCSDS空间链路协议
发布日期:
2015-08-11
DVB-S2标准(参考文献[1])提出了先进的调制技术(QPSK、8PSK、16APSK和32APSK)和具有近香农编码方案(LDPC码)的大范围编码速率(从1/4到9/10)。这种大量的调制和编码方案允许满足特定任务约束的各种可能性。
此外,为了最大限度地提高遥测系统的吞吐量,似乎可以根据链路的可变条件调整传输波形(和有用的数据速率)。DVB-S2标准实际上可以实现可变编码和调制(VCM)模式,该模式按照预定的时间表(例如,遵循动态链路预算)使传输方案适应信道条件。
当信道可用于提供反馈(例如,通过遥控链路)时,可以使用自适应编码和调制(ACM)模式动态调整传输方案。
使用DVB-S2标准进行遥测使通用超大规模集成电路(VHSIC)硬件描述语言(VHDL)知识产权(IP)模块用于开发成为可能。广泛实施的标准的使用简化了寻找发射或接收设备以检查兼容性的过程。最后,对于地面部分,可以重用为电信市场开发的一些电信DVB-S2接收机或专用集成电路(ASIC)。
ISO 20207:2015是一个适配配置文件,描述了如何使用DVB-S2标准传输用于遥测目的的CCSDS传输帧。CCSDS和DVB-S2之间的接口基于参考文献[2]中已经介绍的附加同步标记(ASM)和信道访问数据单元(CADU)。
DVB-S2作为一个完整且自给自足的标准在本适配文件中使用,来自DVB-S2的定义和规范仅适用于本推荐标准的上下文。然而,个别DVB-S2功能或组件(例如VCM/ACM、8-PSK和高阶调制)可能会在未来的推荐标准中被CCSDS重用、重新定义和/或重新指定。
The DVB-S2 standard (reference [1]) proposes advanced modulation techniques (QPSK, 8PSK, 16APSK, and 32APSK) and a wide range of coding rates (from 1/4 to 9/10) with near-Shannon coding schemes (LDPC codes). This high number of modulation and coding schemes allows a wide range of possibilities to satisfy specific mission constraints.
Moreover, to maximize the telemetry system throughput, it appears possible to adapt the transmitted waveform (and the useful data rate) to the variable conditions of the link. The DVB-S2 standard can actually implement Variable Coding and Modulation (VCM) mode, which adapts the transmission scheme to the channel conditions following a predetermined schedule (for example, following a dynamic link budget). When a channel is available to provide feedback (e.g., via a telecommand link), the transmission scheme can be dynamically adjusted using the Adaptive Coding and Modulation (ACM) mode.
The use of the DVB-S2 standard for telemetry makes possible the use of generic Very High Scale Integrated Circuits (VHSIC) Hardware Description Language (VHDL) Intellectual Property (IP) modules for developments. The use of a widely implemented standard simplifies finding transmitting or receiving equipment to check compatibility. Finally, for the ground part, some telecom DVB-S2 receivers or Application Specific Integrated Circuits (ASICs) developed for the telecom market could be reused.
ISO 20207:2015 is an adaptation profile describing how to use the DVB-S2 standard to transmit CCSDS Transfer Frames for telemetry purpose. The interface between CCSDS and DVB-S2 is based on the Attached Synchronization Marker (ASM) and Channel Access Data Unit (CADU) already introduced in reference [2].
DVB-S2 is used in this adaptation profile as a complete and self-sufficient standard, and definitions and specifications taken from DVB-S2 are applicable only in the context of this Recommended Standard. However, individual DVB-S2 functions or components (e.g., VCM/ACM, 8-PSK, and higher-order modulations) might be reused, redefined, and/or respecified by CCSDS in future Recommended Standards.