UA129184U - DEVICES FOR DETECTION OF DIGITAL SIGNALS IN STRONG NOISES - Google Patents

Abstract

The device for detecting digital signals in high noise contains electronic keys K1 and K2, differentiator, inverter, adder and control circuit. It introduces the same low-pass PC filters, main channel differentiator, sampling key and decision scheme.

Description

The useful model relates to radio engineering, in particular radio receiving and amplifying devices, and can be used in digital signal processing systems.

Well-known devices for detecting digital signals contain an optimal filter, a sampling key and a decision-making scheme (| - Sklyar B. Digital communication: Translated from English - M.:

Publishing house "Vilyame", 2003. - 1104 o. However, these devices provide a signal-to-noise gain of 0-3 dB or even less, which is a disadvantage of these solutions. The closest in essence is the patent of Ukraine for the invention No. 87299 dated 07.10.2009,

Makarenko 0.0O., Tretyakov V.O., Tertychyn H.M. "Device for compensation of interference during amplification and restoration of digital signals" - (21. However, this device provides a gain in the signal-to-noise ratio of about 6 dB, which is due to the fact that the noise voltage at the output of the integrator with the reset of the compensation channel always starts from zero, and the voltage noise in the main channel can take any value, both positive and negative.

The basis of a useful model is the task of creating such a device for detecting digital signals in strong noise, which would provide a much greater gain in the signal-to-noise ratio.

For this purpose, in the well-known digital signal interference compensation device, which contains electronic keys KI and K2, a differentiator, an inverter and a control circuit, the new thing is that the same low-frequency AC filters are introduced into the main and compensation channels, a differentiator of the main channel, a key acquisition of Kv samples at the output of the adder and decision-making scheme.

In the claimed device, the task is solved by the fact that the same linear circuits are installed in both channels, namely: low-frequency high-frequency filters and differentiators, fig. 1.

Thus, the channel noises are subjected to the same processing, which provides a significantly greater gain in the signal-to-noise ratio that occurs at the output of the device (over 12 dB).

In fig. 1 shows the structural diagram of the device. The device contains electronic keys KI and K2, differentiator of compensation channel 1, the same low-frequency VS-filters in both channels, differentiator of the main channel 2, inverter 3, adder 4, key for obtaining Kv samples at the output of the adder, decision-making circuit 5 and control circuit 6; to the control inputs of electronic keys

K1 and K2 receive a periodic pulse sequence with a pulse duration of t - 0.5 Ts, a pulse sequence with a duration of tv - 0, t is received at the Kv key.

The device works like this. A mixture of a useful smoothed digital signal and noise (Fig. 2) enters the input of the CI key! of the main channel and the input of the differentiator | compensation channel. In the compensation channel, the signal and noise are differentiated. Electronic keys КИ and К2 work synchronously and close for a time of т1-0.5Тs, where Те is the duration of the digital signal. Signal emissions at the output of differentiator I, caused by the edge and decay of the digital signal pulse (see Fig. 2), are cut off by the K2 key, thus, only differentiated segments of noise of duration t are received at the input of the VS filter of the compensation channel. The derivative of the signal at the interval t is equal to zero. After the high-pass filter, only noise enters the input of inverter 3, the output of which is connected to one of the inputs of the adder. With the help of inverter C, the same intensity and anti-phase noise of the channels are set. In the main channel, after the CI key, segments of the signal and noise with a duration of t-0.5Ts are fed to the input of the HC filter, the output of which is connected to the input of the differentiator of the main channel 2. At the output of the AC filter of this channel, the signal has the form shown in Fig. . 3. After the differentiator of the main channel 2, the signal will have the form shown in fig. 4. It enters the second input of the adder. Thus, a mixture of signal (Fig. 4) and noise is received at one of the inputs of the adder, and only the inverted noise is received at the other input, due to which the noise at the output of the adder is compensated, and the signal passes further. With the help of the sampling key installed at the output of the adder, the signal samples (Fig. 4) are fed to the input of the decision-making circuit. Samples have a duration of TV - 0.1t. The control circuit 6 forms pulse sequences to control the operation of the КИ, К2 and Кв keys. It is triggered by pulses coming from clock synchronization circuits of a specific digital communication system.

The device can be used in digital signal processing systems for various purposes and it is quite effective.

Claims (1)

USEFUL MODEL FORMULA A device for detecting digital signals in loud noises, containing electronic CI keys! and K2, a differentiator, inverter, adder and control circuit, which differs in that it has the same low-pass filters, a main channel differentiator, a sampling key and a decision circuit, and a CI key is installed at the input of the main channel, 60, the output of which is connected to the input of the C-filter, the output of this filter is connected to the input of the differentiator of the main channel, the output of which is connected to the first input of the adder, a differentiator is installed at the input of the compensation channel, the output of which is connected to the input of the key K2 , the output of which is connected to the input of the AC filter of the compensation channel, the output of the filter is connected to the input of the inverter, the output of the inverter is connected to the second input of the adder, the output of the adder is connected to the input of the Kv sampling key, the output of which is connected with the input of the decision-making scheme; the control inputs of the K1, K2 and Kv keys receive pulse sequences that are launched from clock synchronization circuits of a specific digital communication system. j sya KU feenyayu fut Kn rentu With 1 more: He and ; ze ze - not xx! 4 sen i Madnnzhnid I a: Bi i fen s Ho pechnnn, Z ben 14 Zal, Day Mne vom Boennyi What "Vik baka: azh x zha ni Kn val, pyt ho BI Ni ki koki niny NIK i donya i Ishchuk i rek i their m gg a SHE v nyny ko KM p V Zh vi ME z TA i kvt Y Zh ! CHN CHI and Shin Fi. 1508 coat and rum "horn. With KE eto sha I and ay Fig. 4