The Design And Realization Of The Integration Of Satellite Measurement, Control And Data Transmission

The TT&C and data transmission integrated system of satellite shoulders the dual task of TT&C and data transmission.It not only requires the system to have good ranging precision,but also requires high data transmission rate.From the point of view of measuring accuracy and data transmission rate,taking the development of a satellite as the background and guided by the idea of software radio,the TT&C and data transmission integrated system of satellite is designed.Firstly,using the isochronous service provided by AOS,the data format of the uplink and downlink is designed by using the characteristics of the bitstream service and the insertion service.The different transmission mechanisms are adopted for different types and different needs information to maximize the channel utilization.Secondly,the implementation process of the original digital filter is improved,the design method is simplified,and the signal of different rates can be solved with the same filter.Thirdly,the process of Costas loop is simulated,and the influence of loop bandwidth on carrier synchronization performance is studied.Then,Farrow interpolation filter is used to overcome the problem that sampling rate is not a multiple of the rate of information.The Gardner bit timing signal synchronization method is introduced into the TT&C system,and the loop noise error size under Gauss noise is analyzed,and the influence on tracking accuracy is derived.Finally,the test results of the system based on the FPGA platform and the RF upper and lower frequency converter and the host computer are displayed.The data transmission rate can reach 15Mbit/s.Under the high SNR,the ranging accuracy is within 5cm,and the speed accuracy is within 5mm/s.