Study On Key Technologies Of Integrated Receiver

The integrated receiving technology is the development trend of receiving technologies in the future satellite monitoring areas. The application of integrated receiving technology can largely reduce costs of measurement and control nets and human resources used, bring down the manual intervention level in observing and control activities, and reduce human's improper operations and actions.With the development and progress of space technologies, various types of spacecraft become more and more. At the same time, with the development of communication technologies, signal modulation types of model satellite also continuously develop and progress. Due to coexistence of various types of modulation signal, the automatic identification technology of modulated signals has become one of key technologies for integrated receivers'development. On the basis of careful analysis of the current automatically identification methods for modulated type, this paper expounds the automatic identification method of the modulation signal based on the circular spectrum, and carries on the detailed MATLAB simulation for this method recognition effect. In the third chapter end, the article tests SSCA algorithm of the circular spectrum on the actual hardware platform, and achieves a good effect.The diversity receiving technology is that transmit signals carrying the same information by different paths, different frequencies and different polarizations, merge each branch signal in some way at the receiving end, and extract the information. The diversity receiving technology in the application of integrated receivers can better inhibit signal fadeout, improve the noise ratio of received signals, capture and track the target signal more quickly and accurately in the process of measurement and control. Therefore, the diversity receiving technology is another key technology for development and implementation of integrated receivers. According to the main influencing factors of the diversity technology, namely the same frequency adjustment and SNR estimation, the fourth part of the paper carries on the detailed analysis and discussion. Aimed at defects of the existing methods of the same frequency and phase, this paper puts forward a method of the same frequency and phase based on cross-correlation, which has better solved the problem of adjustment methods limited by modulation types. In the aspect of signal SNR estimation, the time domain method has been mostly used. This paper proposes a method which uses Fourier transformation for SNR estimation in the frequency domain. This method is simple and achieves a better result, which is simulated by MATLAB.