Tt & C Side Tone Ranging Key Technologies And Fpga Implementation

At present, our country has constructed C band TT&C system. S band TT&C system and TDRSS system are been building. Ranging terminator is an important function unit, and it provides location information of the flight. Side tone ranging has the highest accuracy in TT&C ranging system. Based on a project of institute 10 of CETC, in this thesis, side tone ranging terminal of integrated baseband equipment is studied and implemented.The contents of this paper are as follows:1) Based on rigors signal analysis, spectrum expressions of direct digital frequency synthesis (DDS) are presented by employing discrete Fourier transform (DFT) and Fourier transform (FT).The output characteristics of DDS with ideal parameters are discussed. Then the distribution and amplitude of output spectrum of DDS are provided in presence of phase truncation. Then a model of phase truncation is build with Systemview to test our conclusions. At last review techniques and methods of spur reduction.2) The received signal has low SNR and large Doppler in TT&C system, so an improved FFT technology is employed to accelerate the carrier fast and correct capture.3) This paper presents the theory and the structure composition of side tone ranging system and a new approach on side tone acquisition and phase match is suggested on orthogonal correlation. And this paper applies a smoothing method to process the phase data and reduce the phase error. The SNR deteriorated result in limiter in ranging signal path is analysis. Finally error analysis is done and some methods are suggested to reduce the error of rang measure.Finally a side tone ranging terminal is completed successfully and the equipment has been tested.