The Digital Estimates Of Carrier Characteristic Parameters

As the carrier of spectrum analysis technology in power system of carrierdetection, mechanical fault diagnosis, which are widely used in many fields, suchas the noise signal analysis of the sonar system and the image processing, carrierfrequency spectrum analysis technology is playing a more and more importantrole in the daily production and the scientific research in the field of people.However, in the actual engineering application, carrier frequency spectrumanalysis technology has the certain problem, that the discrete spectrum offrequency, amplitude and phase are obtained by Fourier transform of the carriersignal in time domain is compared with the theoretical numerical exist certainerrors, especially in the presence of noise, the error generated at this timebecoming greater, this to a certain extent, limits the application of spectrumanalysis in carrier in engineering.In the current carrier frequency spectrum analysis, the energy center ofgravity method is a relatively mature, relatively high accuracy spectrum analysistechnology. This paper first introduces that the research significance of carrierdigital characteristic parameters estimates and analyses the research status ofdigital download potter character parameters estimation in the absence of noiseand noise background. Secondly, this article introduces the basic concept ofcarrier of discrete spectrum, and analyze the causes and study of the carrier signalis generated when the error of the discrete spectrum analysis. At the same time,this paper also studies the carrier frequency spectrum analysis in the most widelyused symmetric window function in time domain and frequency domaincharacteristics for application technology, researching on time domain symmetricwindow function correction for the carrier signal characteristic parameters laidthe foundation. In this paper, the energy center of digital analysis of carriercharacteristic parameters of non noise background method, obtaining the correction accuracy of frequency, amplitude and phase, and using the rectangularwindow, the Blackman window function symmetric spectral analysis of carriersignal. Then this paper studies in noisy conditions using the correction accuracyof energy centrobaric correction method for carrier characteristic parameters, andanalyzing the effects of using symmetric Blackman window function on thecorrection precision, subsequent analysis of digital estimate of carriercharacteristic parameters using symmetric Blackman window function in whitenoise channel. Finally, this paper，based on the statistical characteristics of carriersignal, proposes a correction method based on statistical feature of carrierfrequency, and analysis symmetric window function in different cases infrequency correction. This kind of method put forward, and relative to the energycenter of gravity method can reduce the computational complexity, and makecomputational method relatively simple.MATLAB simulation analysis shows that in the absence of background noise,through using different symmetric window function on the carrier signalspectrum analysis, the Blackman window function has good correction accuracy;Through the analysis of the simulation in noisy background, people know that hemain reason of the correction precision of carrier signal, to a certain extent,affecting the accuracy of correction at this time is that the noise in the channel.Through the simulation analysis based on statistical feature of carrier frequencycorrection method relative to the center of gravity method is not only simplecalculation, but also improving the energy calibration accuracy.