Research And Implementation Of Satellite Sidetone Ranging Technology

Ranging technology of highly precision and long distance in aerospace aspect is significant direction of research in TT&C(telemetry,track and command)system,guaranteeing the Spacecraft launch and position.Sidetone ranging technology is widely applied in TT&C system of USB constitution in China,because of highly precision and measuring quickly.This thesis make the plan what sidetone ranging system operate,ameliorate the key algorithm and improve the measuring precision.Measuring signal modulate to uplink channel via PM method.Therefore,demodulating the measuring signal and measuring phase difference between signals are both emphasis of the thesis.Carrier synchronization algorithm is core of PM demodulating.This thesis adopt second-order frequency-locked loop auxiliary third-order phase-locked loop architecture,to achieve PLL synchronized highly to carrier phase and adapt to environment of low SNR.The architecture adopt efficient frequency detector,aiming to acquisition frequency swiftly;at the same time,adopt high performance phase detector,meeting the demand of tracking carrier phase.After simulation,result indicated that the architecture can satisfy system needing.This thesis ameliorate the digital correlation algorithm to measure phase difference between Tx and Rx signal.The algorithm based on orthogonal double channel correlation principle achieve phase match,improve precision,and simulate the algorithm in Matlab software under different situation.Finally,according to result of simulation,the thesis give some suggestions on reducing phase jitters.In the end,the thesis achieve the whole system function in platform based on FPGA and AD9361.The platform jointed to testing device finished the ranging experiment.