Development Of Payload Data Simulator With A Rate Of 1200Mbps

With the development of science and technology,the performance of satellit e payload is increasing,its function is becoming more and more powerful,and the size of payload data packet is increasing rapidly.As a result,the huge amount of data proposes great challenge the satellite data transmission subsystem.Due to the impact of research and development cycle and economic cost,real payloads are difficult to be applied directly to the test and debugging of data transmission subsystem.To ensure the research and development of the data transmission subsystem,and to achieve the comprehensive test of its performance,satellite ground automatic test system requests payload data simulation equipment with high speed and large capacity urgently.Based on the analysis of existing simulation equipment and combined with the technical requirements and the development trend,a design of payload data simulator based on PXIe is proposed in this thesis,with its design idea and working principle are presented in detail.The design takes full advantage of the PXIe platform’s high-speed data transmission capabilities and a wealth of shelf products,with outsourcing chassis and embedded controller.According to the modular thinking,the simulator functional unit is divided into data source module and data loading module.For the large-capacity storage needs of the system,this paper uses external centralized storage,selecting PXIe-8261 high-speed data hard drive with a storage capacity of 2.9TB as a data source module.For the needs of multi-channel high-rate data scheduling and loading,PXIe-7972 Flex RIO with self-research adapter is selected to be data loading module.The module uses the Gigabit transceiver TLK2711 A as an output interface chip,with high-speed PCB design technology to complete the adapter design.At the same time,the simulator can receive commands from the integrated test server and feedback status through the network port.The control of the system is done by the embedded computer and the Flex RIO FPGA,whose control logic is completed by Lab VIEW FPGA programming technology,respectively,in the HOST VI and FPGA VI.In the data flow control,data stream disk playback technology,DMA FIFO technology,ping-pong cache technology and high-speed data and serial conversion technology make that the data from the high-speed data hard disk is read out,at a steady rate of continuous loading to the interface chip to meet the system’s high-speed data output requirements.Top-level control software is written in Lab VIEW,integrated with HOST VI,to achieve system functions with the hardware.The test results show that the payload data simulator presented in this paper can store 4 high-speed load packets,which can output 6 high-speed payload data at the same time,and the effective data transmission rate can reach 1200 Mbps.The simulator’s storage capacity and data transmission interface can be flexibly changed according to demand,with good versatility.Therefore,the payload data simulator designed in this paper can meet the requirements of design index and can reliably realize the task of payload data simulation,which can be directly used for satellite data transmission system test and provide reference for the design of other highspeed data sources at the same time.