SU944122A1 - Device for varying phase in communication channel - Google Patents

Description

(54) DEVICE FOR MEASURING CHANGES IN THE SIGNAL PHASE OF A COMMUNICATION CHANNEL

one

The invention relates to ectrosis, in particular to electrical measurements in communication, and can be used to measure phase deviations in tonal frequency (PM) channels.

A device for measuring the phase of the communication channel is known, comprising a matching unit, the output of which is connected via the phase detector to the input indicator and to the generator input KOHTpCkjib-j of a full signal, the output of which is connected to the second input of the phase detector 1.

However, the known device is not able to select multiplicative jumps against the background of phase jumps caused by additive, 5 reasons (impulsive noise, level jumps, etc.).

The purpose of the invention is to improve the measurement accuracy by selectively measuring phase jumps from additive and multiplicative interference.

For this, a device for measuring the phase change in the communication channel, comprising a matching unit, the output of which

through a phase detector connected to the input of the indicator. and to the input of the pilot signal generator, the output of which is connected to the second input of the phase detector, a series-connected threshold unit, a time interval generator, a memory unit, a comparison unit, an display control unit and an additional indicator are inputted the output of the phase detector is connected to the input of the threshold unit and to the second inputs of the memory unit and the comparison unit, the third inputs of which are connected respectively to the second and third outputs of the driver time intervals, and the second input of the display control unit is combined with. the first input of the comparison block.

FIG. 1 shows the structural electric circuit of the proposed device; in fig. 2 - time diagrams of his work.

Claims (1)

The device contains a matching unit 1, a control signal generator 2, a phase detector 3, an indicator 4, a threshold 394 block 5. a memory block 6, a block 7 comparing the noni, a driver 8 time intervals, a block 9 of display control and an additional indicator 1O . In addition to FIG. 1 letters denote: a- the output of the phase detector 3; the output of the threshold unit 5; -at 2. - shaper outputs 8 time intervals; - output of memory block 6; 6 - output of the comparison unit 7; EC- output of control unit 9 {chdikatsii; - output shaper 8 time intervals. The device works as follows. The control signal passed through the communication channel, through block 1 is fed to the first input of the phase detector 3. The second input cj "30Boro detector 3 from the output of the generator 2. receives a signal whose frequency is equal to the frequency of the control signal and phase to the mathematical expectation phase of the control signal. The signal proportional to the phase deviation from the output of the phase detector 3 is supplied to the indicator 4, which records the phase jigger, and to the threshold unit 5. In the absence of phase outliers that exceed the set threshold, the threshold unit 5 does not operate, while the driver 8 time intervals are not produces pulses that permit operation of block 6 and block 7, with block 9 being closed and no change in the testimony of the operator 10 of the oracle occurs. When the threshold block 5. registers the phase deviation transients over the set threshold (time -t, t / i of fig. 2), it starts the shaper of 8 time intervals. After a time interval set depending on the constant PLL time (for the PM T channel, 0.3, this time phase jump in the PM channel reaches a maximum), the driver of 8 time slots allows operation of block 6, which remembers the phase value at time fc + t, or t + x, and this value of the amplitude of the phase jump enters the first input of block 7. At time t / j T and 2. + (. 41 (-time determined by the channel bandwidth of 2 l), block 7 compares memorized value of the amplitude of the phase jump at time instant -fc + ti and tg. current moment time If the values of the film at these moments coincide, block 7 records the presence of a phase jump, whose amplitude through the block, 9 displays: on the indicator 1024 If the phase value does not coincide at these moments of time (-t and -b + tg / - Li L1 1 - g in Fig. 2) the phase jump is not registered and the comparison block 7 locks the block 9. From the moment of storing the amplitude of the supposed phase jump at times tf + G and -t, + g to moments of time -bi + G j and t. The sending of 8 time intervals from the generator prohibits the recording of the new value of the jump amplitude in the block 6 (T f the so-called dead time). The measured phase value is practically free of errors due to jigger and additive interference, since the PLL ring filters these components with a given degree of accuracy. The technical and economic effect of the proposed device lies in the fact that it allows to measure phase jumps in the communication channel due to multiplicative reasons, since this parameter is normalized in GOST 21655-76, which has not yet been metrologically, because it is impossible it was distinguished, when measured by known devices, phase jumps caused by additive and multiplicative causes. In addition, in the proposed device, the measurement result is not affected by the time constant of the PLL system. To obtain the same results with the help of existing devices, it would be necessary to simultaneously measure the phase jigger and impulse noise and level loss, for example, using the AIPP-2 device, record the measurement results, for example, using a chart recorder and then compare the results to the same ones. same time points. At the same time, the accuracy of measuring the phase jump using a known device is significantly lower due to the influence of the constant time of the FAP system and it is necessary to have additional instruments and an extra manual operation — comparing their readings, i.e. solving the set task using known devices is very cumbersome. It requires several types of devices and the accuracy is low. The proposed device allows you to simultaneously measure both the values of the phase jigger and the multiplicative phase displacements with a single device. Cove povpiennoy differentiated with precision. Apparatus of the Invention A device for measuring phase phase in a communication channel, comprising: matching, the output of which is connected via the phase detector to the indicator input and to the input of the pilot signal generator whose output is connected to the second input of the phase detector, which is aimed at improving the measurement accuracy by selectively measuring phase jumps from additive and multiplicative interference , a series-connected threshold unit, a time interval generator, a memory unit, a comparison unit, an indication control unit, and an additional indicator are inputted, while the phase output the detector is connected to the input of the threshold unit and with the second inputs of the memory unit and the comparator unit, the third input of which is connected respectively to the second and third outputs of the time interval generator, and the second input of the indication control unit is combined with the first input of the comparator unit. 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