SU1478347A1 - Device for measuring noise level in speech pauses - Google Patents

Abstract

The invention relates to telecommunications. The purpose of the invention is to enhance the functionality by measuring the signal-to-noise ratio. The device contains y-1, integrator 3, ADC 4, register 5, adder 6, shaper 7 control pulses, r-r 8 clock pulses, element 9. To achieve the goal, quad 2, two multiplexers 10, 11 are entered into the device , three adders 12, 13, 14 and block 15 division. The introduction of these elements allows the separation of noise and signal and the determination of their relationship. 2 Il.

Description

The invention relates to telecommunications and can be used to control the quality of telephone and radiotelephone communication channels.

The purpose of the invention is the expansion of functionality by measuring the signal-to-noise ratio.

In FIG. 1 shows a structural electrical diagram of the proposed | θ device; · FIG. 2 is a timing diagram explaining its operation.

A device for measuring the noise level in pauses of speech contains an amplifier 1, a quadrator 2, an integrator 3, an analog-to-digital converter (ADC) 4, a register 5, a first adder 6, a driver 7 of the control pulses, a generator of 8 clock pulses, the element And 9, the first and the second 20th multiplexers 10 and 11, the second, third and fourth adders 12-14 and the division unit 15.

The device operates as follows. 25

Amplifier 1 is a normalizing one, it removes the frequency band corresponding to the telephone channel band from the input signal, matches the signal by the level for normal operation of quad 2, and the norm determines the ADC 4 setting, and therefore, the digitized signal at the output of ADC 4 cannot exceeding this norm, Quadrator 2 converts the signal received from amplifier 1 into a signal proportional to ^ 5 of the input process power, and injects it into integrator 3, where it is integrated during the action of the signal from the first output of driver 7 (Fig. 2a), and during the action of the signal from the third output of the driver 7 (Fig. 26) is converted to digital form in the ADC 4 and stored in the internal register of the ADC 4 until the next signal (Fig. 2B). The ADC is triggered by a pulse drop (Fig. 26) and stops by the leading edge of the next pulse.

The digitized signal C of the ADC 4 enters the first adder 6, where 50 from it is deducted the signal recorded in register 5 and corresponding to the noise power that was determined (or installed) earlier. The presence of transfer at the output of the first adder 55 6 indicates that the number received from ADC 4 is greater than the number received from register 5, i.e. the input process contains a useful signal, which is separated by the first adder 6 from noise and enters the fourth adder 14. In the fourth adder 14, it is added to the signal present in it, and the result of addition is stored in the fourth adder 14 by the signal from the fourth output of the driver 7 (Fig. 2d). At the same time, if there is a transfer, the second multiplexer 11 passes the contents of register 5 from the second output (in direct code) through the multiplexers 11 and 10 to the second input of register 5, where it is stored by the signal (Fig. 2d). In addition, the signal from the second multiplexer 11, corresponding to the noise power, arrives at the third adder 13, is added to its contents and is also stored by the signal (Fig. 2d). If the ADC 4 receives a signal smaller than the contents of register 5 at the first adder 6, then the transfer is not generated and this means that a signal has arrived that corresponds to the new noise power ·, the value of which is less than that recorded in register 5, namely, this value is passed by multiplexers 14 and 10 to register 5, where it is recorded by the signal (Fig. 2d). Those. at the outputs of register 5, the current value of the noise level can be monitored. In the absence of transfers from the first output of the first adder 6, adders 13 and 14 due to the presence of the And 9 element do not update the contents of their registers, but retain their previous value. This means that noise is summed only when there is a signal. At the end of the observation interval according to the signal from the sixth output of the former 7 (Fig. 2e), the contents of the adders 13 and 14 are written into the registers of the division unit 15, which calculates the signal-to-noise ratio. According to the signal from the fifth output of the shaper 7 (Fig. 2e), the adders 13 and 14 are reset. According to this signal, the first multiplexer 10 passes signals to register 5 not from the second multiplexer 11, but from the second adder 12, where a number from the installation input of the device is added to the signal from the second multiplexer 11. The minimum signal search engine containing register 5, the first adder 6, the second multiplexer 11 will not respond if the noise power increases, therefore, after each measurement cycle, the noise power slightly increases artificially relative to the obtained value, and the minimum value search engine starts to work . The additive can be made constant and implemented, for example, in the form of a shift by one or more digits of the number coming from the output of the second multiplexer 11. In the general case, it can vary depending on the rate of change of the noise level.

Since the additive is introduced only at the beginning of the measurement cycle, it acts only from the moment the cycle begins to the first pause in this cycle.

Claims (1)

SUMMARY OF THE INVENTION A device for measuring the noise level in pauses of speech, comprising an amplifier, the input of which is a signal input of a device for measuring noise in pauses of speech, an And element, a register, a serial generator of clock pulses and a driver of control pulses and a series-connected integrator, analog-to-digital a converter and a first adder, the second input of which is connected to the first output of the register, characterized in that, in order to expand functionality by measuring signal / noise, a quadrator, first and second multiplexers, a second, third and fourth adders and a division unit are introduced, while the amplifier output is connected through a quadrator to the first input of the integrator, the second and third inputs of which are connected respectively to the first and second outputs of the control shaper pulses, the input and the third, fourth and fifth outputs of which are connected respectively with the first input of the division unit, with the second input of the analog-to-digital converter, with the first input of the register and with the first input of the first multiplex pa connected to the first inputs of the third and fourth adders, the outputs of which are connected respectively to the second and third inputs of the division unit, the fourth input of which is connected to the sixth output of the control pulse shaper, the fourth output of which is connected to the first input of the element And, the second input of which is connected with the first input of the second multiplexer and with the first output of the first adder, the second output of which is connected to the second input of the fourth adder, the third input of which is connected to the output of the And element, output n the first multiplexer is connected to the second input of the register, the second output of which is connected to the second input of the second multiplexer, the third input of which is connected to the first input of the first adder, and the output of the second multiplexer is connected to the second input of the third adder, the third input of which is connected to the third input of the fourth adder, the first input of the second adder, the second input of which is the installation input of the device for measuring the noise level in speech pauses, and to the second input of the first multiplexer, the third input of which about connected to the output of the second adder. Editor L. Zaitseva Compiled by V. Slepakov Tehred L. Serdyukova Corrector I. Muska Order 2374/55 Circulation 627 Subscription VNIIIPI State 113035, Committee for Inventions and Discoveries at the State Committee for Science and Technology of the USSR Mdskva, Zh-35, Raushskaya nab. Production and Publishing Plant Patent, Uzhhorod, st. Gagarina, 101