Method and device for performing spectrum analysis of a wanted signal or noise signal

摘要

A method and device for performing spectrum analysis of a signal in a plurality of frequency bands with respective different frequency resolutions. The method includes a data acquisition step and a subsequent data evaluation step for every frequency band. The data acquisition step and the subsequent data evaluation step proceeds cyclically and continuously for every frequency band of the spectrum analysis. The corresponding device for performing spectrum analysis of a signal cyclically stores a scanning sequence of the signal for every frequency band in one circular buffer each. A discrete Fourier transformer uses the cyclically stored scanning sequences to calculate the spectral values pertaining to the respective frequency band.

主权项

1. A method for spectral analysis of a signal in several adjacent frequency bands with different corresponding frequency resolutions in each case, which comprises at least one data-acquisition step and a subsequent data-evaluation step for each frequency band,
wherein the data-acquisition step and the subsequent data-evaluation step proceed cyclically without interruption for each frequency band of the spectral analysis, the data-acquisition step includes a step of sampling the signal at a sampling frequency according to the Nyquist criterion to be at least double the value of the upper frequency of the respective frequency band; and a step of storing the respectively-sampled values of the signal in a ring memory associated with the respective frequency band, the data-evaluation step includes a digital spectral-estimation method, and the sampling step includes for each frequency band at least one subordinate sampling step and the second and each subsequent subordinate sampling step includes a low-pass filtering step having different bandwidth and a subsequent undersampling, wherein the low-pass filtering step filters out the respective frequency band of the previous sampling step and the frequency bands are adjacent to one another, wherein spectral values already calculated in a Fourier analysis of a higher-frequency overlapping frequency band are used as temporary spectral values for lower-frequency frequency bands, until all spectral values in the lower-frequency frequency bands have been calculated by means of Fourier analysis.