Study on Spacecraft Communication and Ranging technologies over Ultra-Long Distance for Future Jupiter Mission

更好的接收机灵敏度，结合基于它的涡轮编码方案，并通过机载再生操作提高测距链路能力，是JAXA未来执行木星任务计划所必需的。在我们的研究中，我们已经建立并验证了我们的地面站系统模型，以展示我们的新接收机的更好性能，开发我们的涡轮编码电路板，并完成我们的第一个再生测距系统，将它与我们预先开发的机载应答器模型相结合。地面站模型被构建为VME总线系统上的一组电路板，其中包含从a /D转换器到中频信号从s波段下变频到任何必要的接收功能（如解调和解码）的所有连接点。在载波捕获中更窄的锁相环带宽及其稳定的运行被设计为能够在比以往低得多的输入电平下解调剩余载波PM调制信号。在信噪比为-0.2dB的情况下，从载波采集到符号同步的硬件损耗小于0.1dB。该输入电平条件符合CCSDS turbo编码定义的要求。这意味着我们新开发的接收机可以很好地用于turbo编码方案。作为地面站模型的一部分，介绍了测距系统。这是我们的再生测距方案的第一个演示，该方案使用我们的新深空应答器，可使测距链路提高15 dB以上。

The better receiver sensitivity, incorporation of turbo coding scheme based on it, and improved ranging link capability through onboard regenerative operation are necessary for the future Jupiter mission program to be conducted by JAXA. In our research, we have built and verified our ground station system model to demonstrate the better performance of our new receiver, to develop our circuit board for turbo coding, and to complete our first regenerative ranging system combining it with our pre-developed onboard transponder model.The ground station model was constructed as a set of circuit board on VME bus system, which contains all the Junctions ranging from A/D converter to follow IF signals down-converted from S-band to any necessary receiver capabilities like demodulation and decoding. Narrower PLL bandwidth in carrier capturing and its stable operation were designed to enable demodulation of residual carrier PM modulation signals at much lower input level than ever. The hardware loss through the carrier acquisition to symbol synchronization was evaluated to be less than 0.1dB with the input of -0.2dB of S/N. This input level condition corresponds to the requirement of CCSDS turbo coding definition. It means that our newly developed receiver works well as one for turbo coding scheme.The ranging system was introduced as a part of our ground station model. It was a first demonstrator of our regenerative ranging scheme, which leads to more than 15 dB improved ranging link with the use of our new deep space transponder.