论文部分内容阅读
目前,大部分以地面为基础的空间遥测采集系统码速率达到每秒几兆比特(Mbps),NASA的跟踪与数据中继卫星系统(TDRSS)能支持大于300Mbps的下行码速率。另外,先进的TDRSS(ATDRSS)预计能支持650Mbps以上的码速率。NASA未来的大规模工作计划,例如:自由号空间站和地球观察系统都需要这么高的码速率。在哥达德空间飞行中心,正在研制一个帧同步器电路板,其最低码率为300Mbps,并提供一套可编程功能,例如:32位相关、搜索—校核—锁定策略、码滑动容限、惯性态(fly wheeling)等。另外,累积质量数据的产生、在板自诊断、状态/控制处理都综合在一块电路板中。这些功能和极高码率之所以能够实现,是因为在设计上采用了NASA为支持由空间数据系统咨询委员会制订的空间遥测数据系统标准而研制的砷化镓(GaAs)超天规模集成(VLSI)电路。本文将描述这电路板所完成的功能以及实现这些功能所用的VLSI器件。
Currently, most ground-based space telemetry acquisition systems have code rates in the order of few megabits per second (Mbps) and NASA’s TDRSS (downlink and data rate) systems support downlink rates greater than 300 Mbps. In addition, the advanced TDRSS (ATDRSS) is expected to support code rates above 650 Mbps. NASA’s future large-scale work programs, such as the Liberty space station and the Earth observation system, require such a high code rate. At the Goddard Space Flight Center, a frame synchronizer circuit board is being developed with a minimum code rate of 300Mbps and a set of programmable features such as 32-bit correlation, search-check-lock strategy, code slip tolerance , Fly wheeling and the like. In addition, the cumulative quality data generated in the board self-diagnosis, status / control processing are integrated in a circuit board. These capabilities and very high code rates are achieved because of the NASA GaAs superscale scale integration (VLSI) designed to support NASA’s space telemetry data system standards developed by the Advisory Committee on Spatial Data Systems ) Circuit. This article describes the functions performed by this board and the VLSI devices used to implement these functions.