Übersetzung für "Leistungsdichtespektrum" in Englisch

In signal processing, white noise is a random signal with a constant power spectral density.

The power spectral density is obtained via a Fourier transformation.

It is also possible to determine the power density spectrum.

By a suitable choice of the filter the power-density spectrum decreases at lower frequencies and increases at higher frequencies.

The periodic power density spectrum generated by the periodic optical filter 2 is hereafter called a frequency-encoded spectrum.

In the described optical CDMA method, the power density spectrum of a light source is subjected to periodic spectrum encoding.

For the sake of simplicity, the power density spectrum S'q of the quantizing error q' is initially assumed to correspond to white noise.

The output of the correction circuit 16 provides a power density spectrum ?2 (f) which contains only the proportions of the spectrum of the stochastic disturbances ?2.

In a method disclosed for example in German patent document DE 44 29 419 A1, the power density spectrum of the ground echo from a radar-Doppler system is evaluated.

Good convergence properties are attained with the NLMS algorithm if the echoes have a uniform broad-banded power density spectrum.

The minimum of the error sum for the individual segments is found by way of dynamic programming, in which auxiliary values are initially computed from the power density spectrum and stored as Tables from which the autocorrelation coefficients are easily determined for individual frequency segments which are required for the computations in the dynamic programming process.

If the turnon delay of the laser is increased by decreasing the bias current IV, the optical pulse width decreases, the shortest pulse duration becoming smaller than T. In the power density spectrum the zero point then moves away from fB and a measurable value appears at the frequency fB which increases with increasing turnon delay.

The oversampling of the interpolation filter 1 ensures that the power-density spectrum of the further quantization noise is reduced by the ratio F2/F1=N in the desired frequency range.

The voltage U2, which corresponds to the nominal value of the above-mentioned frequency line in the power density spectrum, is applied to the second input of the second comparator K2.

The filter must be a filter which is optimized for a specific order for which the power density spectrum of the quantization noise is minimal.

In one embodiment of the first criterion, detection of precipitation is now possible by integrating amplitude spectrum A(f) or the power density spectrum (A(f)) 2 as the square of the amplitude spectrum over a first frequency interval 51 corresponding to a distance interval INT 1, which is situated between minimal distance R min and limiting distance R lim .

However, the latter has the effect, as will be discussed below, that the error PSD (PSD =power spectral density) of the prefiltered signal is no longer a white noise, but is approximated to the signal PSD of the prefiltered signal depending on the degree of clipping.

The noise signal should preferably resemble white noise in order to prevent a misinterpretation as a desired echo in the downstream evaluation, i.e. should preferably be a stochastic signal with constant power spectrum and normal distribution.

Light emitted by the light-emitting diode 1, to which the periodic filter 2 bestows a periodic power density spectrum, is modulated externally by the optical modulator 3.

The power density spectrum obtained from the noise voltage extends over a wide frequency range and, on the basis of its profile, provides more information than the measurement of the impedance at a single frequency.

This additional digital signal processing may, for example, modulate the data and control signals to be transmitted via the speech channel such that they may appear similar to speech signals in their properties, such as, for example, in their frequency bandwidth, their autocorrelation function and their power density spectrum.

Light fed to the N×N star coupler therefore has a periodic spectrum, i.e. the power density spectrum comprises areas of high power density and areas of very low power density at regular intervals.

With a known power density spectrum of the radiated interference, such as is shown for purposes of illustration in FIG. 3, the power density can be influenced in a targeted manner over a specific frequency range, for example, in order to avoid exceeding maximum values of power density at predefined frequencies.

In accordance with one embodiment of the present invention, to assign the input signals to a defined signal situation, at least one of the classification variables number of signal components, level of a signal component, distribution of the level of the signal components, power density spectrum of a signal component, level of an input signal and/or a spatial position of the source of one of the signal components is determined.

To this end the classification unit 51 can determine at least one of the classification variables number of signal components, level of a signal component, distribution of the level of the signal components, power density spectrum of a signal component and/or level of a signal component and the assignment to a defined signal situation can be undertaken as a function of at least one of the classification variables.

By using the apparatus 500, the radiation source 106 A can remain continuously switched on, with the result that the optical component 200 and the measurement device 230, which is coupled to the optical component 200, see the continuous radiation of the continuously switched-on radiation source 106 A and low-frequency components in the power density spectrum will thus not occur.