CCSDS Protocol Analysis And CORTEX Monitor Terminal Development

Consultative committee for space data system (CCSDS) is an international organization for standardization, which consisted of multinational space organization. CCSDS establishes standard communication system structure, protocol, and service for space data system. CCSDS aims to establish a series of space data system standards through technical consultation, to achieve the widest international cooperation and mutual support. If Chinese aerospace techniques want to keep up with the world, the standard of data system must accord with the CCSDS.The paper studies several key techniques in CCSDS and analyzes the performance of multiplexing mechanism and telemetry channel code. Then we improve the CORTEX monitor terminal which applied in satellite telemetry; make it communicate with computer in serial port and telnet.CCSDS adopts two levels multiplexing mechanism to realize multi-user dynamically common channel. This paper analyzed packet channel multiplexing completed in VCLC sublayer and virtual channel multiplexing completed in VCA sublayer. In analysis, we establish a packet service model and obtain the distribution of frame internal, and discussed the relation between packet delay and frame efficiency. Based service time distribution difference, we obtain distribution of packet number and queue of frame in system through queue theory.CCSDS telemetry channel codes ensure the reliability of the space data transmission. The paper studies the performance of Turbo code and the concatenated code which makes up of RS code and convolutional code. We discuss the Bit Error Rate of the convolutional code, Turbo code encoder and decoder theory as well as the performance in AWGN channel and Rician channel, and present the result of simulation.CORTEX monitor terminal is an integrated command Ranging and Telemetry system, which based on PC architecture and Windows NT operating system. The CORTEX monitor terminal contains many functions, such as telemetry processing, satellite telecommanding, satellite ranging and simulation...