A Real Time Power Spectrum Analysis Of Low Frequecy Radom Signal

In this paper, a real time power spectrum analysis of low frequency radom signal based on digital filters is introduced, and a design way of real time arithmetic is given. The correlation method and FFT method of the power spectrum estimation could not completely reflect the concept of the power spectrum of the non-stationary random signals because of data truncation. And the method of parametric spectrum estimation could not realize the analysis of a fixed percentage bandwidth which is necessary for noise signal, the structure vibration signal, etc. But the filter method avoids truncating data and it can achieve the analysis of a fixed persantage bandwidth easily. The digital filter can realize the time division multiplexing and the frequency division multiplexing,so the real time power spectrum estimation can be achieved completely at the full frequency axes integrating resampling technique.The first chapter introduces the class of the power spectrum analyzer. And it compares the correlation method and FFT method with the digital filter method of the power spectrum estimation.In chapter two the basic theory and implement method of power spectrum analyzing are given in detail.The third chapter introduces the design of the power spectrum analyzer in hardware. It includes the analogy part design and the modules design in the CPLD chip.Chapter four discribles the sofeware design in DSP chip. The improved arithmetic of multirate-multichannel filtering is also given.