SU1305883A2 - Device for monitoring signal-to-noise ratio - Google Patents

Abstract

This invention relates to radio measurements and is an improvement to auth. No. 1173562. The purpose of the invention is to increase the reliability of the control. The device contains two nonlinear converters 1 and 5, two filters 2 and 10, three rectifiers 3, 4 and 12, a subtraction unit 6, a divider 7, a threshold block 8, an executive block 9, 11, and a block for selecting the maximum signal (BVMS) 13. The goal is achieved by the introduction of a filter 10, 11 11, rectifier 12 and BVMS 13, which are used to extract the convolution of the input signal by the double carrier frequency and clock frequency. This makes it possible to more accurately determine the signal-to-noise ratio with a certain distribution of concentrated noise and improves the noise immunity of the device. 1 il. (L with Vshod N)

Description

The invention relates to a technique of radio measurements, can be used to monitor the state of communication channels in terms of signal-to-noise ratio in the transmission of discrete information, and is an improvement to the invention by the author. No. 1173562.

The purpose of the invention is to increase the reliability of the control.

The drawing shows a structural electrical circuit of the proposed device.

The device for controlling the signal-to-noise ratio contains the first non-linear converter 1, filter 2, the first 3 and second 4 rectifiers, the second non-linear converter 5, the subtraction block B, the divider 7, the threshold block 8, the executive block 9, the additional filter 10 , amplifier 11, third rectifier 12 and block 13 for selecting the maximum signal.

The device works as follows.

With an input signal with a phase modulation of 0-JI, the first nonlinear converter t removes the relative phase modulation of the input signal and the filter 2 separates the voltage at a frequency the carrier frequency of the signal proportional to the square of the input signal.

signal (U

with. 6X

).

The constant component of the signal from the output of the second rectifier 4 is

and"

+ and.

- lgtt i

 Out. In. Bh where Uf xt and U.sx in the same signal voltage and interference.

When squaring the second nonlinear transducer 5, its

output voltage (U jjix Razvno tt - r i + T 2. 2 8i: - s.v p.bh

This voltage is applied to one of the inputs of subtraction unit 6, the second input of which receives the voltage passed from the output of the first rectifier 3 through selection unit 13

maximum signal. )

The output of block 6 produces a voltage equal to the square of the interference voltage. This voltage goes to one of the inputs of the divider 7, the second input of which receives the voltage from the output of the block 13. As a result, the output of the divider 7 receives a signal proportional to the signal-to-noise ratio which then enters the threshold block 8 and causes or

does not trigger the executive unit 9.

In the event that the device is affected by a signal with multipositional phase modulation, the signal is not dispersed at the output of the first nonlinear converter 1 and the signal from the output of filter 2, and hence from the first rectifier 3

block 13 is not received. However, in this mode (as with the modulation of O-7 (), with a limited signal spectrum, a sweep occurs at the clock frequency of the input signal, This convolution

selects an additional filter 10 and through the amplifier 11 and the third rectifier 12, the voltage proportional to the square of the input signal, is fed to the second input of the unit 13, which selects the maximum signal from the two incoming inputs to its inputs (in this case, from the output of the third rectifier 12) . Then everything happens as described.

The amplifier 11 is designed to equalize the magnitude of the collapsed signal at the double carrier frequency and clock frequency.

In addition, with the modulation of the OFL, a certain distribution of interference may prove that the convolution at the double carrier frequency is either absent or, in general, may be less than at the clock frequency. In this case, the more correct signal / interference ratio will be determined by the presence of an additional filter 10, amplifier 11, the third rectifier

12. Thus, the presence of these blocks and block 13 with a certain distribution of concentrated noise improves the noise immunity of the device.

Claims (1)

Invention Formula A device for controlling the signal-to-noise ratio according to the author, St. No. 1173562, characterized in that, In order to verify the accuracy of the control, the output of the first vyl metlel is connected to the second inputs of the subtraction unit and the divider through the input unit for selecting the maximum signal, the second The input of which is connected to the output of the first nonlinear converter through an additional filter, an amplifier and a third rectifier introduced in series.