JPS5815985B2 - The most important thing in the world - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to - an apparatus for determining the average noise power per minute and for signaling its exceedance from a limit value;
The present invention relates to a quality monitoring device for radio relay links, comprising a device for determining the excess of energy from a number of critical levels.

Conventional devices of this type were capable of determining the average noise per hour up to that time and were equipped with a processor for this purpose.

However, according to recent theories, the device can be simplified because the determination of the average noise per hour up to that point can be omitted.

The invention is based on the idea of reducing the cost of the complete device by a factor of 40 by also replacing the processor with simpler equipment.

According to the invention, the first-mentioned device above consists of two parallel shunts and a switch, one of the shunts containing an amplifier, a first square generator for measuring the instantaneous noise power, and a first square generator for measuring the instantaneous noise power. the other shunt is constituted by a second square generator and a second resistor having a value smaller than the first resistor corresponding to the degree of amplification in the first shunt. wherein the switch connects either the first shunt or the second shunt to the first analog integrator, and the switch connects the second shunt to the output terminal of the second square generator. The simpler installation described above can be obtained since it is operated by a comparator connected similarly to an analog integrator.

Note that the square generator referred to in this specification is an electrical device that generates an output voltage that is the square of the input voltage, and its use in the present invention is to magnify the influence of fluctuations in the input signal.

Hereinafter, the present invention will be explained with reference to drawings showing block diagrams of embodiments.

In the figure, 1 is θ~ which can be adjusted in steps of 1 decibel.
10 dB adjustable attenuator.

The input impedance is asymmetric and 75 ohms.

This attenuator allows the input sensitivity of the noise measuring device to be adjusted to standard sensitivity -28 decibels (dBr).

In the high frequency mixer 2, the input signal is divided into a part that measures the noise power of the noise measurement channel and another part that measures the baseband energy received via the input.

A noise measurement channel with a bandwidth of 7 kHz is filtered from the baseband signal by the crystal filter 3.

The signal of this channel is then converted by a mixing stage 4 and a local oscillator 5 to an intermediate frequency of 65 kilohertz.

Two methods can be used to design the circuit described above, so that measurements can be made on two noise measurement channels:

That is, (1) for the 960 channel system, filter 3 is for 4,765 kHz and oscillator 5 is for 4,830 kHz; (2) for the L800 channel system, filter 3 is for 9,073 kHz and oscillator 5 is for 4,830 kHz. is for 9.138 kilohertz.

The intermediate frequency section 6 includes an amplifier 7 with an amplification degree of 50 decibels.
This is followed by an amplified active MF (medium) with a center frequency of 65 kHz and a noise bandwidth of 3.1 kHz.
frequency) bandpass filter 8.

The amplification degree of this latter circuit part can be adjusted by means of a device designated by 9, so that the total amplification degree of the intermediate frequency section 6 is approximately 9
It can be adjusted between 0 and 100 decibels.

The instantaneous noise power is measured by two square generators 11 and 12 in the square section 10, while the average noise per minute is determined by an analog integrator 13 placed after the square generators 11 and 12. Do it at 14.

The analog integrators 13 and 14 are much simpler than ordinary digital integrators.

The square generator used in this case has its own linear dynamic range of about 25 dB.

Since this does not satisfy the conditions, a special circuit is used, namely two identical square generators 11 and 12 in two branches.

One of the shunts has an amplification degree of 2, which is provided before the square generator 11.
It is equipped with a 0 decibel amplifier 15.

The other branch has a squaring generator 12 without a preamplifier.

Furthermore, a comparator 16 is connected to the output terminal of the square generator 12.

A comparator 16 connects an integrator from the output terminal of the square generator 11 to the output 7- of the square generator 12 when the signal at the input terminal of the square generator 120 increases by 20 dB and the square generator 11 approaches its operating limit. It has a limit value adapted to switch 13 input terminals.

A resistor 17 is provided at the output end of the square generator 1, and a resistor 18 is provided at the output end of the square generator 12.

At the same time that the comparator 16 performs its switching function, a switching from one input resistor 17 to the other resistor 18 for the integrator takes place.

Since the ratio of the resistance values of these resistors 17 and 18 is equal to the square of the gain of amplifier 15, a smooth transition from one range to the other is obtained.

In other words, the current vs. voltage characteristic curve of the circuit consisting of the amplifier 15, square generator 11, and resistor 17 touches the current vs. voltage characteristic curve of the circuit consisting of the square generator 12 and resistor 18 at one point. , in this respect the transition from the characteristic curve of the former circuit to the characteristic curve of the latter circuit can be made without a voltage jump.

In this way, a total linear dynamic range of 45 dB is obtained, with the first 20 dB of the entire range being generated by the square generator 11 and the last 2 dB being generated by the square generator 12.
5 decibels is ensured.

Integrator 13 measures the excess from a predetermined reference level in the range of 300 to 2,000 pWOp (interference level picowatts measured at the zero relative level weighted by the estimated noise voltage). However, the integrator 14 serves to measure the excess from a constant level of 47.500 pwop.

The input terminal is integrated for 1 minute. The output voltage is applied to comparator 19.20.

These integrators are reset once every minute, after which a new integration period begins.

To account for this reset, each integrator is provided with two integrating capacitors 21, 22 and 23, 24 respectively, since the capacitors cannot be completely discharged for a short time after each measuring cycle. It is.

One capacitor acts as an integrating capacitor and the other capacitor is shorted for 1 minute.

When the integrator is reset, the roles are reversed so that there is a fully discharged capacitor at the beginning of every measurement period.

Switching of the capacitors is performed by FET switches controlled from a central digital clock 25.

The baseband section includes a baseband filter 26, a square generator 27, an integrator 28, and four comparators 29 to 32.
It consists of

The baseband filter 26 is ■, f with a slope of 124 dB/octave.

(Shutdown layer wavenumber) = 316 kHz high-pass filter 3
3 and 2 f respectively with a slope of 136 dB/octave.

-4188 kilohertz (960 channels), fo=8
204 kHz (1800 channels) low-pass filter 34; 3, each f.

=5235 kilohertz (960 channels), fo=1
0255 kHz (1800 channels) pre-emphasis filter 35.

In this way, the baseband fills are each -316
~4188 kHz (960 channels), 316
It is formed for a band of ~8204 kHz (1800 channels).

Considering the 1800 channel signal which has a higher level than the 960 channel signal, the 1800 channel baseband.

The filter includes 2.8 dB of additional attenuation.

Integrator 28 is arranged in the same way as integrators 13, 14 for measurements in the noise measurement channel.

When the bandwidth is quite large, the square generator described above cannot be used.

Therefore, a thermocouple is used as the square element.

There are a total of six comparators as shown below.

1. 300~ depending on the level of excess level 109WOp
a comparator 19 for the noise measurement channel with a variable limit adjustable between 200 OpWOp; .2, 47.5;
a comparator 20 for the noise measurement channel with a fixed limit for the exceedance level of 00 pWo p;
and comparators 29-32 for measuring baseband energy with a certain limit of measuring 6 dB.

The output terminals of these comparators are equipped with signal lamps 36 (LEDs) for checking the correct operation of the noise measuring device.

The logic component consists of a clock 25 and a 6-bit buffer register 37.

The digital clock consists of a circuit that generates small pulses from the main frequency, and these pulses are used to reset and switch the integrator and to read the comparator output signal into register 37.

At the same time, minute pulses are derived and used to record signals.

The LED lamp 38 indicates the operation of the clock.

Under the control of a small pulse, the 6-bit buffer register 37 reads information from the output terminal of the comparator.

- minutes, this parallel information remains available for further processing at the output terminal of the buffer register.

[Brief explanation of the drawing]

The drawing is a block diagram showing one embodiment of the present invention. 1...Attenuator, 2...High frequency mixing section,
3...Crystal filter, 4...Mixing stage,
5... Local oscillator, 6... Intermediate frequency section, 7, 15... Amplifier, 8... MF band filter, 1L12, 27...・Square generator,
13.14... Analog integrator, 16°19.
20.29-32...Comparator, 17,18...
...Resistor, 25...Digital clock, 33...High pass filter, 34...Low pass filter, 35...Pre-emphasis filter , 36... Signal lamp, 37...
Buffer register.

Claims (1)

[Claims] 1 a first device for determining the average noise power per unit time and signaling the excess from its limit value; and a second device for obtaining the linear dynamic range necessary for determining the average noise power per unit time, wherein the first device comprises two parallel branches. one of the shunts consists of an amplifier 15, a first square generator 11 for measuring the instantaneous noise power and a first resistor 17, and the other of the shunts a second square generator. 12 and a second resistor 18 having a resistance value lower than that of the first resistor, and the ratio of the resistance values of the two resistors is the same as that of the amplifier 15.
and is equal to the square of the gain of This comparator and the second analog integrator 140 input are both connected to the output side of the square generator 12, and the analog integrator 1
3.14 is a wireless relay link quality monitoring device characterized by being reset once per minute.