SU744909A2 - Noise relative level sensor - Google Patents

Description

(54) RELATIVE LEVEL INTERFERENCE SENSOR

one

The invention relates to telecommunications.

Known sensor relative interference level on the author. St. No. 354520, containing series-connected amplitude limiter and band-pass filter, the output of which is connected to the inputs of two frequency discriminators, as well as series-connected adder, amplifier-limiter for maximum and minimum and low-pass filter, while the outputs of frequency discriminators are connected via appropriate polarity limiters to the inputs of the adder JlJ.

However, the lime sensor relative noise level does not have sufficient accuracy.

The purpose of the invention is to improve accuracy.

To do this, in the sensor of the relative interference level according to the author. St. No. 354520, containing a series-connected amplitude limiter and a band-pass filter, the output of which is connected to

inputs of two frequency discriminators, as well as series-connected adder, amplifier-limiter for maximum and minimum, and a low-pass filter, while the outputs of the frequency and discriminators through the corresponding polarity limiters are connected to the inputs of the adder, the output of the low-pass filter is connected to the key, between the output of one limiter the polarity and the control input of the key are connected in series with the first two-sided limiter, the first additional low-pass filter, the first threshold element and the element nt And, and between the exit

15 of the other polar limiter and the other input of the AND element are connected in series with the second two-sided limiter, the second additional low-pass filter and the second threshold element.

Claims (1)

FIG. Figure 1 shows the structural electrical circuit proposed by the first device; in fig. 2 - statistical characteristics of beating processing paths, in FIG. 3 is a diagram of the frequency of beats, depending on the interference / signal ratio, and the parameters of non-linear testing; in fig. 4 shows the dynamic characteristics of the paths (Fig. 4a, b) and the operating output characteristic of the sensor with echo signals and concentrated disturbance (Fig. 4c). The relative noise level sensor contains a series-connected amplitude limiter 1 and a band-pass filter 2, the output of which is connected to the inputs of frequency discriminators 3,4. The discriminator outputs are connected via polarity limiters 5.6 to the inputs of the adder 7. The device also contains two-sided limiters 8.9; amplifier-limiter for maximum and min-mum 10; low pass filters 11, 12 13; threshold elements 14, 15; element 16, key 17, connected to the inlet of the low-pass filter 13. The device operates as follows. The input of the amplitude limiter 1 is given by a signal of amplitude frequency and c and an interference with frequency f p, amplitude and n. At the output of amplitude limiter 1, we obtain an oscillation with a constant amplitude, but is modulated in frequency according to the law of beating (see fig.Z) The function of the beat frequency is determined by the interference / signal ratio. . Band-pass filter 2 limits the beating frequency emissions. After demodulation by frequency discriminators 3 and 4 and limiting the i 5 and 6 limiters, the signal corresponding to the beat frequency is fed to the adder 7, during which a V-like discriminatory characteristic is formed, and then to the bilateral limiters 8 and 9. At the output of the two-sided limiters 8 and 9, the values of the frequency of the beatings are found, directly adjacent to the signal values (in the band L.f {). With an increase in the relative level of interference outside this zone, the relative residence time of frequency b decreases. in the zone (see FIG. 3), and with it the value of the constant component allocated at the output of low-pass filters 11, 12 at points 1 and C. As a result, the dependence of the voltage of the constant component on the relative The interference level is as shown in Figure 4a. With echo signals, these dependences are symmetric about the axis of ordinates (UH / UC - 1), and for concentrated interference with amplitude D DC, the indicated voltage is O. This allows you to solve the problem using threshold elements 14 and 15, element 16 and key 17. At the output of element 16, the signal appears only if at the output of low-pass filters 11, 12 at points I and D the voltage simultaneously falls below the threshold U POR of FIG. 4a), i.e. with the appearance of a concentrated disturbance with the amplitude of the DC UE and with a frequency lying outside the gaps. This signal affects the key 17, which increases the constant potential (see Fig. 4c). If there is no interference or echo signals, the voltage at the input of the threshold elements 14 and 15 practically does not fall below the threshold, the signal at the output of the element 16 does not exist, and the key 17 passes the voltage Ujji to the output of the sensor. Thus, the proposed device accurately and unambiguously distinguishes the echo signals from the concentrated interference at the relative level of the latter U / U.l The technical and economic efficiency of the sensor relative to the level of interference consists in increasing the accuracy, the Formula invented and- The sensor of the relative level of interference according to the author. St. No. 35452О, about tl and h and yush with the fact that, in order to increase accuracy, a key is connected to the output of the low-pass filter, between the output of one polar limiter and the control input of the key, the first two-way op limiter is connected in series, The first additional low-pass filter, the first threshold element and the AND element, and between the output of another polar limiter and another input of the And element, the second two-sided limiter, the second additional low-pass filter and the second threshold element are connected in series. & fc five) 2L /, fo / (/ 7, 4 / s but) 2A / JL L / Ujel 24 / - / Phage.1