Order for pulse assessment in relation to digital services

Abstract

Arrangement for evaluating pulse disturbances with regard to their influence on digital radio systems, characterized by the parallel connection of an RMS rectifier and quasi-peak detector with defined time constants and an evaluation circuit which superimposes the values ​​of the quasi-peak detector and RMS rectifier in such a way that above a pulse repetition frequency an evaluation is carried out with the RMS detector and below this value an evaluation is carried out with the quasi-peak detector.

Description

[0001] The invention comprises a method and an arrangement for implementing the method, which serves to evaluate pulse interference in digital radio systems. The arrangement is used to evaluate pulse interference and allows for faster measurement for stationary interferers and interference with higher pulse repetition rates compared to the prior art.

[0002] According to the prior art, patent DE 3525 472 C2 describes an arrangement for detecting a pulse-like disturbance, which consists of an arrangement of parallel modules, wherein the output signal of both modules is compared by means of a comparator.

[0003] According to the state of the art, such as in patent DE 101 26 830 B4, a weighting rectifier for evaluating pulse interference with respect to its impact on digital radio systems is described. This weighting rectifier consists of a cascaded structure of an RMS value and a mean value detector. First, the RMS value is determined over a specific integration time. Subsequently, the RMS values ​​are averaged using a mean value detector. This arrangement allows the weighting curves to be obtained with a specific measurement uncertainty in accordance with the CISPR 16-1-1 standard. The detector is referred to as an RMS average detector in the CISPR 16-1-1 standard.

[0004] A disadvantage of the arrangement in DE 101 26 830 B4 is that, even with high pulse repetition rates of the input signal, the signal must be evaluated over the entire integration time of the effective value and average value detector. The time constant of the average value detector is 160 ms or 100 ms to simulate an analog pointer instrument. To obtain a measurement with sufficient measurement accuracy, the detector must be stabilized. For this reason, it is necessary to select a measurement time significantly longer than the time constant of the simulated pointer instrument. Although DE 101 26 830 B4 teaches that a measurement can be accelerated by reducing the time constant of the average value detector, a detector modified in this way no longer meets the requirements of the CISPR 16-1-1 standard. For a sequential measurement at several thousand frequency points, this results in measurement times of several hours.

[0005] A further disadvantage of the arrangement in DE 101 26 830 B4 is its combination with a receiver, which allows evaluation at only one frequency point. If measurements are to be performed at multiple frequency points, a time-consuming sequential measurement must be performed.

[0006] DE 103 92 151 B4 describes a method and an arrangement for implementing the method, wherein the interference signal is measured in the time domain and converted into a spectral signal by means of a transformation, using a detector model to superimpose multiple spectra. DE 103 92 151 B4 teaches that an evaluation is performed simultaneously at multiple frequencies, accelerating the measurement by several orders of magnitude.

[0007] German Patent Application DE 10 2006 005 595 A1 describes a method and system for measuring interference emissions in real time. The application of short-time Fourier transformation and the simulation of the quasi-peak and RMS detectors at several thousand frequency points simultaneously accelerate the measurement. The quasi-peak and RMS detectors are implemented digitally.

[0008] The CISPR 16-1-1 standard defines that the rms-average detector behaves like an RMS detector above a certain pulse repetition rate, and like an average detector with a simulated time constant for a pointer instrument below this pulse repetition rate. Therefore, test specimens with a pulse repetition rate greater than the break frequency can be measured directly with the RMS detector. Since the RMS detector has a shorter time constant than the pointer instrument, it is possible to obtain a correct measurement result with sufficient accuracy even with a shorter measurement time.

[0009] DE 103 15 372 A1 discloses a method and a device for providing a measurement signal. The measurement signal is based on a plurality of pulses of a sampled input signal. When implementing the method, the time interval between the plurality of pulses of the input signal is first determined. Pulses that each have the same time interval are then assigned to a group. The plurality of groups are then arranged sequentially to generate the measurement signal.

[0010] A quasi-peak detector is known from the state of the art, which has a charging constant T C , as well as a discharge constant T D and a mechanical time constant for a pointer instrument T MThe behavior for different time constants of the quasi-peak detector is described in the CISPR 16-1-1 standard. The time constants T C and T D be adjusted so that below the bend frequency the display corresponds to the rms-average detector within a defined deviation.

[0011] It is therefore proposed according to the invention to carry out the evaluation by means of a parallel arrangement of quasi-peak detectors with modified time constants (T C and T D) and rms-average detector and a downstream evaluation unit in order to achieve an acceleration of the measurement for test objects with higher pulse repetition rates compared to the state of the art. Preferably, the time constants of the quasi-peak detector are selected such that the display corresponds to the behavior of the rms-average detector for pulse repetition rates below the knee frequency as described in the CISPR 16-1-1 standard. Preferably, the detectors for bands A (9 kHz-150 kHz), B (150 kHz-30 MHz), CD (30 MHz-1 GHz) and E (1 GHz-18 GHz) are adapted such that evaluations in accordance with the requirements of CISPR 16-1-1 are obtained for pulse repetition frequencies below the knee frequency.

[0012] Preferably, the evaluation unit consists of a module which compares the value of the quasi-peak detector and the effective value detector and outputs the smaller value.

[0013] The arrangement offers the particular advantage that the RMS values ​​can be read at any time. For pulse repetition frequencies above the knee frequency, the result can be output even when the pointer instrument is not in steady state. This opens up the possibility of shortening the measurement time for interference with high pulse repetition rates, thus accelerating the measurement.

[0014] If the measurement time is shorter than the settling time of the pointer instrument, the reading of the RMS detector will always be higher than that of the quasi-peak detector. However, if the measurement time is longer than the time constant of the pointer instrument, the reading of the quasi-peak detector below the break frequency will be lower than that of the RMS detector. Above the break frequency, the reading of the quasi-peak detector on the pointer instrument will be higher than that of the RMS detector.

[0015] Therefore, in an advantageous further development, if the measurement time is shorter than the time constant of the pointer instrument, the digital evaluation unit always outputs the larger value after comparing the quasi-peak value and the effective value. If the selected measurement time is significantly longer than the time constant of the pointer instrument, the smaller value is output after comparing the quasi-peak value and the effective value.

[0016] An advantageous further development describes an arrangement that uses a module that measures the emission in the time domain. A cascaded module performs a transformation to the frequency domain. Another cascaded module applies the detector model of the rms-average detector. This allows for evaluation at multiple frequency points simultaneously.

[0017] A further advantageous development uses the arrangement described in DE 10 2006 005 595 A1, in which the effective value and quasi-peak value are calculated at multiple frequency points, and the quasi-peak value detector is implemented with modified time constants. An evaluation circuit is connected downstream, which superimposes the values ​​of the quasi-peak value and effective value detector in such a way that above a certain pulse repetition frequency, an evaluation is performed with the effective value detector, and below this value, an evaluation is performed with the quasi-peak value detector.

[0018] In the following, individual embodiments are shown in figures

[0019] An embodiment of the arrangement for carrying out the method is shown in Fig. 1 shown.

[0020] The input signal is evaluated using the modified quasi-peak detector 1 and the rms detector 2. The output signals of detectors 1 and 2 are superimposed by a digital evaluation unit 3 to produce the measured value of an rms-average detector according to the CISPR 16-1-1 standard.

[0021] The simulation of the arrangement according to the invention is shown in Fig. 2 shown.

[0022] In Fig. Figure 2 shows the evaluation curves of an rms-average detector according to the CISPR 16-1-1 standard for the AE bands. The points corresponding to the definition in the CISPR 16-1-1 standard are shown. The behavior of the inventive arrangement is shown as a line. The behavior lies within the tolerance limits of CISPR 16-1-1.

[0023] In Fig. Figure 3 shows a simulation of the modified quasi-peak detector and the RMS detector. The measurement time is 2 s, which is significantly longer than the time constant of the pointer instrument.

[0024] In Fig. Figure 4 shows the superposition of the values ​​for a case where the measurement time is significantly longer than the time constant of the pointer instrument. The measurement time is 2 s. It can be seen that for all pulse repetition frequencies, a display is provided in accordance with the CISPR 16-1-1 standard.

[0025] In Fig. Figure 5 shows a simulation of the modified quasi-peak detector and the RMS detector. The measurement time is 100 ms, which is shorter than the time constant of the pointer instrument. It can be seen that the RMS detector's level above the knee frequency satisfies the indication requirements of the CISPR 16-1-1 standard.

[0026] In Fig.Figure 6 shows the superposition of the values ​​for a measurement time shorter than the time constant of the pointer instrument. The measurement time is 50 ms. It can be seen that for all pulse repetition frequencies, a reading is obtained in accordance with the CISPR 16-1-1 standard, provided the pulse repetition frequency is greater than the break frequency of 100 Hz.

Claims

[1] Arrangement for evaluating pulse disturbances with regard to their influence on digital radio systems, characterized by the parallel connection of an effective value rectifier and quasi-peak value detector with defined time constants and an evaluation circuit which superimposes the values ​​of the quasi-peak value detector and effective value rectifier in such a way that above a pulse repetition frequency an evaluation is carried out with the effective value detector and below this value an evaluation is carried out with the quasi-peak value detector. [2] Arrangement according to claim 1 characterized by that the charge and discharge constant of the modified quasi-peak detector is selected in such a way that, after superimposing the effective value and quasi-peak value for certain pulse repetition frequencies, there is agreement with the evaluation curves of the CISPR 16-1-1 standard within a defined measurement uncertainty. [3] Arrangement according to claim 1 characterized bythat the digital evaluation unit compares the quasi-peak value and the effective value and outputs the smaller value. [4] Arrangement according to claim 1 characterized by that the digital evaluation unit compares the quasi-peak value and the effective value and outputs the larger value. [5] Arrangement according to claim 1 or 2 characterized by that the digital evaluation unit compares the quasi-peak value and the effective value, outputs the larger value below an adjustable measuring time and outputs the smaller value above the measuring time. [6] Arrangement according to one of the preceding claims characterized by that the evaluation is carried out digitally. [7] Arrangement wherein the interference signal is digitized by means of a module and converted into a spectral signal by means of a cascaded module and the spectral signal is evaluated with an arrangement according to one of the preceding claims.

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