SU698135A1 - Noise suppressor - Google Patents

Description

one

This invention relates to communications and can be used in radio telephone receivers.

A noise suppressor is known, containing a series-connected limiter and a signal determining unit, as well as a key, the input of which is connected to the output of the limiter - 1.

The known noise suppressor has a relatively low quality of suppression.

The purpose of the invention is to improve the quality of suppression.

The goal is achieved by the fact that the noise suppressor containing a series-connected limiter and a signal determining unit, as well as a key, the input of which is connected to the output of the limiter, are connected in series to a control pulse shaping unit and a pause determining unit. Between the output of the detection unit cffrnana and the control input of the key, the control unit is turned on, the first enabling input of which is connected to the clock output of the control pulse generation unit, and the second enabling input is connected to the output of the pause detection unit. The control input of the pause determination unit is connected to another output of the control unit. The control input of the signal determining unit is connected to the output of the pulses of the resetting unit of the control pulse formation.

The drawing shows the structural electrical circuit of the noise suppressor.

The yummal suppressor contains the limiter 1, the signal determining block 2, the key 3, the control pulse shaping block 4, the pause determining block 5, and the control block 6 — The output of the key 3 is outputted by the suppressor output 1.

Squelch works as follows.

Claims (3)

The low-frequency signal from the output of the limiter 1 radio receiver (not drawing not shown) is fed to the block 2. The parameters of block 2 and block 5 are selected based on the statistical characteristics of the speech signal. If at the input of block 2 there is a mixture of speech signal and noise at a signal-to-num ratio exceeding 4-6 dB, then the output of block 2 is signal 1. In this case, when a pulse from the clock output of block 4 arrives at the first block enable input 6 control at its output sets the signal that opens the key 3. As a result, sigaal with limiter 1 passes to the output of the squelch. The reset pulses, coming from the output of the reset pulses of block 4 to the control input of block 2 and from the control block 6, to the control input of block 5, are brought to the initial state by blocks 2 and 5. In the case of the absence of a speech signal at the course of the radio receiver, to the block 2, the noise voltage is supplied from the output of the limiter 1. Since only noise is present, from the output of block 2 to the input of control block 6, a signal O is received. Lree, the next pulse arrives from the clock output of block 4 to the first enable input of control block 6, the state of its output does not change and the reset pulse coming from its other output to the control input of block 5 does not appear. As a result, after time, formed by block 5, from its output to the second enabling input of control unit 6, signal 1 is received. Control unit 6 closes key 3, and the signal from limiter 1 output to output; noise suppressor does not pass | The control unit remains in such a state-of-the-art hop until it is placed at it - (meino signal 1 from block 2 and the optimal output of block 5. 5.4 The proposed noise suppressor can significantly improve the intelligibility of the received speech signals. Formula of the invention A noise suppressor, containing a series-connected limiter and a block for determining the signal, as well as a key, the input of which is connected to the output of the limiter, characterized in that, in order to improve the quality of suppression, a control impulse forming unit is connected in series Both the pause detection block and the block between the output of the signal determining block and the control input of the key are connected to the control unit, the first permitting input of which is connected to the clock output of the control pulse shaping unit, and the second enabling input is connected to the output of the pause detecting unit, while the control input the pause detection unit is connected to another output of the control unit, and the control input of the signal detection unit is connected to the output of the reset pulses of the control pulse generation unit. Sources of information taken into account in the examination I. US Patent N 3437937, cl. 325-478, published. 1969 (prototype).