SU741412A1 - Device for compensating for radio signal non-linear distortions - Google Patents

Description

The invention relates to radio engineering and can be used in pulse radionavigation systems in measuring systems, de monitoring pulsed signals, in receiving-indicators of pulse phase radio navigation systems, etc. The device for compensating non-linear distortion of radio signals, which contains an inverter, is known , n delay blocks and a series-connected attenuator and adder, the combined inputs of the inverter and attenuator as well as the output of the adder are respectively the input and output However, the known device provides an insufficiently small non-linear distortion factor in the output signal due to the appearance at the device input of the phase shift of radio-pulse signals of ground stations when they are distributed by scientific research institutes along the route. The purpose of the invention is to reduce the non-linear distortion factor in the output signal. To do this, a device for compensating for non-linear distortion of radio signals containing an inverter, n delay blocks and a series-connected attenuator and adder, the combined inputs of the inverter and attenuator, as well as the output of the adder are respectively the input and output of the device for compensating non-linear distortion of radio signals, the switch, while the control input of the switch is connected to the analyzer.level output, and the signal inputs to: outputs n delay blocks, whose inputs are combined and connected to the output of the inverter and the output of the switch is connected to another input of the adder, the output of which is connected to the input of the level analyzer. FIG. 1 shows the structural electrical circuit of the proposed device in FIG. 2 - signal plots at the input and output of the device; in fig. 3 - plots of the generated signal for different values of the phase shift of the input signal. The device for compensation of non-linear distortion of radio signals contains

inverter 1, attenuator 2, p delay blocks 3, switch 4, adder 5 and level analyzer 6; 7 - device input, 8 - device output.

Device compensation for nonlinear distortion of radio signals works as follows.

An input radio pulse e (t) (Fig. 2a) with a unipolar envelope arrives at the input 7 of the device. In the absence at the input 7 of the device of the phase shift of the radio pulse e (t) at its output 8, a different polarity signal and (t) is formed (Fig. 26 and plot b of Fig. 3), the half-polar half-waves of which are 9 and 10, equidistant from the characteristic point The tg (symbol reversal point of the bending curve t (Fig. 26) is called the characteristic envelope point (CTO) and is used for tracking in the system of eliminating the ambiguity of the phase reference), are informative for the tracking system, which monitors the signals with gates 11 and 12 (Fig. 2c and Fig. 3), the temporary position which corresponds to the maxima of the half-waves 9 and 10 (figo 26 and fig. 3) From the level analyzer 6, the switch 4 does not receive a switching command and the corresponding delay unit 3 is included in the device, creating a delay of the received signal by exactly half of the carrier frequency period Cr g -B ..

When a phase shift occurs at the input radio pulse e (t) at the output 8 of the device, a signal is generated and (t) (diagrams a or in Fig. 3) depending on the type of propagation path (land, sea or mixed route). The shape of this signal is significantly different from the shape depicted in plot 6 of FIG. 3. In this case, the level analyzer b generates a command to connect the corresponding delay block 3, which creates a delay of the input radio pulse e (t) by the value of iT, which is not equal depending on the phase

go raid. Epures

g, d fig. 3 are built for phase raids, respectively, equal to -0, 1 MKS 0; -4-0.1 µs; +0.02 ms; -0.02 ms

In this device, the level analyzer b can be a set of threshold blocks that produce an estimate of the signal level at point K (Fig. 3), taking into account the sign, or a measure of the displacement At the point K at the point, K, etc. (Fig. 3 ).

For example, when a phase shift of the input radio pulse e (t) is equal to 0.1 of the ISS, the output signal and (t) will look like that shown in the diagram of FIG. 3. In this case, the level analyzer b issues a command to turn off the delay block 3, which creates a delay by the value of tr, and connects the corresponding delay block 3, which creates a delay of the input signal e (t) by the value of SG - + O, 1 μs. As a result, the waveform U (t) at the output 8 of the device will remain

close to the ideal depicted in plot b of FIG. 3

Thus, the proposed device allows the output signal to be maintained almost constant when an additional foray occurs at the input radio pulse signal and, as a result, the signal-to-noise ratio is approximately doubled, which is equivalent to an increase in the power of the emitted signal by 4 times.

Claims (1)

1. Noise-like signals in information transmission systems. Edited by Pestr Kova VB, ed. Soviet radio M., 1973, p. 235 (prototype).