Research Of Digital Satellite TV Receiving System On Ship And Simulation Experiment Based On LabVIEW

With the acceleration of the course of digital satellite television, analog satellite television channels of our country will be terminated and converted to digital gradually. Compared to receive analog signal, digital signal has some factors, such as threshold voltage, narrow width of frequency. So it is harder to receive digital signal than analog signal and needs higher precision for aiming at antenna of satellite. The satellite TV receiving system for receiving analog signal that Chongqing Changjiang River ship photoelectricity science and technology Ltd exploited can not receive digital signal apparently. So it is very urgent to design a suit of satellite TV receiving system on ship to receive digital satellite television channels in order to replace outdated production and capture new market. Geography coordinates and Carrier coordinates is the two coordinates that mobile satellite TV receiving system must face when it tracks the satellite.Based on analysing the two coordinates, this paper deduces the coordinates conversion matrix of geography coordinates to carrier coordinates, resolves how to calculate the azimuth angle and pitching angle of antenna in carrier coordinates, establishs the theory base of mobile digital satellite TV receiving system. LabVIEW is not only a hep virtual instrument platform, because it have powerful function to support peripheral hardware and Control Design and Simulation Toolkit much more, but also a perfect platform to do real time simulation. Therefor this paper attempts to do simulation experiment in LabVIEW, validates the correctness of this arithmetic. This paper analyses and contrasts the strongpoint and shortcoming of different kinds of trace technology, and chooses the method that this item adopts-Program Trace, on the base of it designs the hardware structure based on DSP, and extends a RS232 interface by SPI interface of LF2407. This paper establishs the trace control maths model of mobile digital satellite TV receiving system, and does simulation experiments by using LabVIEW Control Design and Simulation Toolkit, acquires the parameters of trace system controler. Then connects sensors to simulation system, does Hardware-in-the-loop Simulation. The simulation result can achieve the performance demand, confirms that the trace mode and trace arithmetic choosed is feasible and effective. This paper practises LabVIEW application by real time simulation technology relatively successfully, perfects the limitation that virtual simulation can not factually simulate actual problem to a certain extent, provides experience that can be used for reference for real time simulation technology. At last, this paper discusses some problems in course of syetem simulating and points out the next step of the work.