Design Of The Platform Of Time-Frequency Signal Measurement And Analysis With High Precision

A systematic project of the platform for time-frequency signals measurement and analysis with high precision is put forward in this thesis. The platform consists of two mixers , a PC computer with counter card, and special software for measurement control and data analysis, forming a digital, virtual, synthetic, automatic system for time-frequency measurement with high precision.Since 1960', the methods for charactering time-frequency stability in time-domain have been in progress. The methods include Allan variance, modified Allan variance, time variance, Hardamard variance, total variance, time interval error(TIE) and maximum time interval error(MTIE), of which TIE and MT1E are usually used for telecommunication network. The advantages and disadvantages as well as the application extend for those measures are discussed based on the five common noise models. The methods to calculate the confidence interval for each type of frequency stability estimation are studied.The methods of direct measurement with low precision such as frequency and time interval methods and the methods of indirect measurement with high precision such as beat frequency method, dual mixer time difference method and frequency difference multiplying method are supported on the platform. The fundamentals of each method are studied. The quantization error is analysed and the illustration is given for each method.The structures for hardware and software are discussed in detail following the content presented above. The detailed design process of software system is given. The remote measurement and control and remote communication are explored. Several performance parameters of the signal under test can be provided in time-domain and the measurement results report can be shown in the forms of plots and tables. The software system is provided with friendly interface.