Device for measuring the amplitude-frequency characteristics of the communication path
(57) Abstract:Usage: in telecommunications to perform automated measurements of frequency response and group of linear channels of transmission systems on cable, radio and other communication lines. The inventive device comprises a block 1 of the registration and control data generator 2, the resistors 3.1 - 3.4 isolation amplifiers 4.1 - 4.4, measured tract 5 communications, detectors 6, block 7 subtraction, the transmitter 8 and the receiver 16. The device allows a single measurement of the frequency response of the communication path for each of the selected control frequency, which greatly improves performance measurements frequency response. 2 C.p. f-crystals, 5 Il. The invention relates to telecommunication and can be used to perform automated measurements of amplitude-frequency characteristics (AFC) of the group and of linear channels of transmission systems on cable, radio and other communication lines.A device for measuring the amplitude-frequency characteristics of the communication channel containing the measuring generator, a control unit, a measuring unit, a threshold unit, forward and reverse channels.A disadvantage of the known device is a long time smerek the invention is a device, implementing a method of measuring the amplitude-frequency characteristics of the communication path that contains the control unit and data logging measurements, generator, resistors junction, the measured communication path, the detector, the comparator, the transmitter as the signal return path communication receiver as signal amplifiers.The disadvantage of this device is the low performance measurements frequency response of the communication path, as each controlled frequency steps increases the level of the measuring signal as long as no work the comparator at the receiving station, and then check the measurement data and shall include the following frequency of the measuring signal.The purpose of the invention improve performance measurement of the amplitude-frequency characteristics of the communication path by transmission on each frequency of the measuring signal to transfer measurement in a communication channel as the ratio of the amplitudes of the two harmonics of nonlinear distorted vibrations.The aim is achieved in that in a device for measuring the amplitude-frequency characteristics of the communication path containing the serially connected control unit and record measured data, the gene of the junction and the detector, connected in series transmitter, the third resistor junction, a third amplifier, a reverse communication path, the fourth amplifier, a fourth resistor junction and the receiver, the output of which is connected to the input of the control unit and data logging of measurements entered the subtraction unit, the first input of which is connected to the detector output, the second input of the subtraction is input to the reference voltage, and the output of the subtraction unit is connected to the transmitter input.In Fig.1 shows a block electrical diagram of the device for measuring the amplitude-frequency characteristics of the communication path. The device comprises a block 1 control register data measurements, the generator 2, the resistors 3.1. 3.4 isolation amplifiers 18.104.22.168 measured tract 5 connection, the detector 6, block 7 subtraction, the transmitter 8, consisting of the amplifier-modulator 9, the additional generator 10, two bandpass filters 11.1 and 11.2, the frequency Converter 12, the sinusoidal voltage generator 13, an amplifier 14, a reverse path 15 communication and the receiver 16, which consists of two bandpass filters 11.3 and 11.4, two additional detectors 17.1 and 17.2 and divider 18 voltage.In Fig.2 shows a variant of the structural electrical circuits of block 1 governance and region is 20 clock pulses, the counter 21, the d / a Converter 22, 23, an analog-to-digital Converter, a multiplexer 24, the element 25 of the delay memory cell 26, the indicator 27.In Fig.3 shows graphs illustrating the operation of the amplifier modulator 9, where (a) the transfer current-voltage characteristic of the element (bipolar transistor); b) the timing diagram of the input sinusoidal voltage; a timing chart of the output current of the amplifier.In Fig.4 shows graphs of the coefficients Bergk(expansion coefficients of the cosine pulse output current of the amplifier-modulator 9) from the cutoff angle of the output currentwhere the coefficient Berg is the ratio of the amplitude of the IMCspectral component (harmonic) current to the pulse amplitude Imaxcurrent: ato= Imk/Imax.Device for measuring the amplitude-frequency characteristics is as follows.When the button 19 start a generator of clock pulses 20 and the count of these pulses by the counter 21, the output of which is fed code combination on the d / a Converter 22, the output of digital to analog conversion max is 2, the signal passes through resistor 3.1 decoupling amplifier 4.1 and later in the measuring path 5 links, output path 5 connection of the measuring signal passes through the amplifier 4.2 and the resistor junction 3.2 and falls to the input of the detector 6, the output of which goes to the input unit 7, subtraction, where the comparison of the level of the measuring signal with the threshold voltage Up. From the output of the unit 7 subtracting the resulting voltage is fed to the input of the transmitter 8, where the differential voltage is fed to the control input of the amplifier-modulator 9, the second input is connected to the output of the additional generator 10 that generates a harmonic signal. The values of the frequencies of the harmonics of the output signal of the amplifier-modulator 9, containing a nonlinear element, which does not depend on the amplitude of the voltage at its control input, as determined by the frequency of harmonic oscillations from the output of the additional generator 10. As the bias voltage Ecm=Ub(t)=Eb+U2(t) is the output voltage of the block 7 subtraction. The bias voltage at the control input of the amplifier-modulator 9 is not necessarily positive. It is determined by the amplitude of the harmonic oscillations from the output of the generator 10 and the desired range of variation of the cutoff angle. In this case, the block 7 subtraction performs other funny output voltage from block 7, which is determined by the level of the frequency response of the communication path. The circuit elements of the amplifier-modulator 9 are selected so that the bias voltage supplied to its control input, would provide a nonlinear mode of operation of this amplifier 9. In this case, the input of the amplifier is a high-frequency signal, a current which has a cutoff angle and a certain amplitude of the harmonics Im1, Im2This signal is applied to the inputs of bandpass filters 11.1 and 11.2, the first of which is configured on the frequency of the first harmonic component of F1and the second filter 11.2 on the frequency of the second harmonic component of F2=2F1the output signal of the modulator 9. From the output of the second bandpass filter 11.2 frequency of the second harmonic component of Im2is fed to the input of the frequency Converter 12, to the control input of which receives the auxiliary sinusoidal voltage from the generator 13. The converted signal close in frequency to the frequency of the first harmonic component of the output signal of the amplifier-modulator 9, the output of the frequency Converter is supplied to the amplifier 14. From the output of the transmitter 8 signals at frequencies F1and FPpass through the resistor 3.3 rasur interchange 3.4. The signal is then fed to the input of the receiver 16 and falls to the inputs of bandpass filters 11.3 and 11.4. The first band-pass filter 11.3 tuned to the frequency of the first harmonic and the second band-pass filter 11.4 on the frequency of the second harmonic. With outputs of filters 11.3 and 11.4 filtered harmonic components are received at the inputs respectively of the first and second additional detectors 17.1 and 17.2, designed to determine the amplitudes of the first and second harmonic components of the signal. The outputs of the additional detectors 17.1 and 17.2 are connected and the corresponding inputs of the divider 18 voltage intended for finding the ratio between the amplitudes of the first and second harmonics. In Fig.5 shows graphs explaining the operation of the individual blocks of the device and reveal the correspondence between the attenuation tract 5 (upper graph shows the amplitude-frequency response K(F) measured tract 5) and a value of the signal at the output of the voltage divider 18 (lower graph). The number in the circle indicates the number of the block in which physical process is illustrated by the corresponding plot of the voltage. The frequency generator 2 during the time interval measurement of the frequency response t [t1,t2] changes from what ignal output path 5 will also be modified in accordance with the frequency response in the passband tract 5. The envelope of this signal is allocated by the detector 6, and after passing through the block 7 of the subtraction is supplied as a bias voltage to the input of the amplifier-modulator 9, the second input of which receives the harmonic oscillation output from the generator 10. The amplifier-modulator operates in a mode with current cutoff, the value of the cutoff angle is determined by the bias voltage, and therefore, the frequency response of the path 5. The amplitudes of the first and second harmonic components of the modulated signal at the inputs of the respective bandpass filters 11.3 and 11.4 are also determined by the value of the cutoff angle. Therefore, the output signal of the divider 18, the entrance of which serves the above-mentioned harmonic components is also determined by the value of the cutoff angle, and therefore, are positively correlated with the frequency response of tract 5 connection. In practice we often face the task of measuring the frequency Response of the direct path, and the frequency response of the reverse path is known. As follows from Fig.3, with a uniform frequency response of the controlled path of connection and therefore at a stable angle cutoff of the output current of the amplifier-modulator 9 the ratio of the amplitudes of the harmonics will be constant regardless of the magnitude of the damping of oscillations in the reverse path 15 connected. In the case of uneven frequency response value uprazheniya signal at the input of the divider 18 voltage, coming to the entrance of block 1 control. Input unit 1, the control enters the analog-to-digital Converter 23, where in digital form is fed to the information inputs of the multiplexer 24. On the control inputs of multiplexer 24 filed code combination from the output of the counter 21 through the element 25 delay on the frequency at which the currently measured level of response. Depending on the signal at the control input of the multiplexer 24, the measurement result of the frequency response is written in the corresponding cell of the memory 26. The time of measuring the frequency response of the communication path at the same frequency is not determined by the duty cycle and period of the pulses from generator 20 clock pulses. The increase in the content of the counter 21 is set at "1" increases the voltage level at the DAC output, which served as the control input of oscillator 2 and rebuilds it to a specific frequency. As the DAC can be used chip type TO PA, KPA, KPA and other Outputs of the memory cells 26.1. 26. N is connected to the input of the indicator 27 for the purpose of visual status display of the frequency response of the communication path in the measured frequency range.Thus, the proposed device allows a single izmereniya frequency response compared to the prototype. If the measurement results do not depend on the level of attenuation in the reverse path communication. 1. Device for measuring the amplitude-frequency characteristics of the communication path containing the serially connected control units and data logging, the generator, the first resistor junction, the first amplifier, the output of which is input the measured communication path, the second amplifier, the input of which is the input of the output signal measured communication path, the second resistor junction and the detector, connected in series transmitter, the third resistor junction, a third amplifier whose output is the input of the reverse communication path, the fourth amplifier, the input of which is the input signal from the output of the reverse communication path, the fourth resistor junction and the receiver, the output of which is connected to the input of the control unit and recording data, characterized in that the input unit subtracting the first input of which is connected to the detector output, the second input of the subtraction is input to the reference voltage, and the output of the subtraction unit is connected to the transmitter input.2. The device under item 1, characterized in that the transmitter is designed in the form of series-connected generator and amplifier-mod is uceni to the output of the amplifier-modulator, the output of the second bandpass filter connected to the first input of the frequency Converter, a second input connected to the output of the generator, and the output connected to the input of the amplifier, the output of which is combined with the output of the first bandpass filter and an output of the transmitter.3. The device under item 1, characterized in that the receiver is made in the form of serially connected to the first bandpass filter, a first detector and a voltage divider whose output is the output of the receiver, connected in series to the second bandpass filter, whose input is combined with the input of the first bandpass filter and an input of the receiver, and the second detector, the output of which is connected to the second input of the voltage divider.
FIELD: radio communications.
SUBSTANCE: pulse noise is detected upon conversion of signal received into intermediate frequency, noise active time is determined, information signal is disconnected from amplifier incorporated in superheterodyne receiver, noise-affected part of information signal is recovered by eliminating simulator signals during extrapolation, and superheterodyne receiver is checked for serviceability at intermediate frequency.
EFFECT: enhanced precision of superheterodyne receiver serviceability check.
1 cl, 1 dwg
FIELD: radio engineering; diagnostics and repairs of radio equipment.
SUBSTANCE: proposed method includes recording of current criteria of radio and video communication channel conditions, their comparison with desired reference values, elimination of faults detected, and check tests for signals in electric and low-current circuits, replacement of faulty electric and low-current harnesses, units, and assemblies, checkup for signals in circuits of automatic-control, measuring, and recording system and checking-and-recording equipment, and checkup of circuits for normal functioning, whereupon pieces of equipment are subjected to accelerated aging by thermal and mechanical impacts.
EFFECT: enlarged functional capabilities and enhanced reliability of condition inspections.
FIELD: instrumentation engineering; serviceability check of multichannel communication systems.
SUBSTANCE: proposed equipment includes personal computer, multiplexing switch, circuit checkup unit, control unit, multichannel comparison unit, virtual standard, switching unit, output signal shaper, multiplexer, and normalizing unit that has voltage meter and circuit meter.
EFFECT: enlarged functional capabilities of device.
3 cl, 1 dwg
FIELD: multi-channel communication systems.
SUBSTANCE: equipment has comparison block, virtual standard, input and output signal generators, commutator, voltage meter, circuit measuring means and control block.
EFFECT: broader functional capabilities.
2 cl, 1 dwg
FIELD: amplitude-frequency characteristics of quadripoles.
SUBSTANCE: control of quadripole is realized in two stages. At first stage, estimation stage, N counts of measurements results are received during length T of one signal period, and on second stage, analysis stage, during time T received signal estimation results are recognized with determining of class of technical state of object (like breakdown). To realize first stage of control, to present clock pulse generator, first counter, delay element, first register, first AND element, adder, additionally inserted are two keys, two analog-digital converters, second register and operative memory block for estimation results, to realize second control stage additionally to first and second comparison block, indication block, inserted are breakdowns signs memory block, breakdown counters and commutator, and for controlling control stages to present launch element, first counter, second AND element, key element is additionally inserted.
EFFECT: higher speed of operation.
FIELD: radio engineering; serviceability check of communication systems.
SUBSTANCE: proposed method is characterized in that serviceability of communication systems in frequency-adaptive range is evaluated by checking system response to noise situation simulated at its input and its comparison with desired value. To this end time required for tuning to optimal frequency is measured and compared with desired value, and also number of errors is counted and compared with that admissible.
EFFECT: enhanced reliability of estimating serviceability of communication system in frequency-adaptive range.
1 cl, 1 dwg
FIELD: systems for determining amount of available data transfer resources.
SUBSTANCE: for determining amount of resources for data transfer and/or speeds of bits transfer for network connection, with known physical length of cable, measurement of energy spectrum is performed depending on transmission frequency for different types of modems by means of power measuring device, weakening is determined for different physical lengths and thicknesses of cable wires, depending on parameter of cross interference, number of sources and correcting coefficient on bass of energetic spectrum noise level is determined, while by means of gauss transformer module on basis of efficient signal levels and appropriate noise levels amount of data transfer resource is determined for different data transfer modulations and/or modulating codes for predetermined bit transfer speed, then available data transfer resource amount is corrected by means of correcting coefficient, including average deviation of stored amounts of data transfer resources from efficiency amounts of resources of data transfer, and on basis of stored efficient recourses for data transfer with utilization of known physical length of determined network connection available data transfer resource for appropriate network connection is determined.
EFFECT: possible determining of amount of available data transfer resources for certain connection.
3 cl, 4 dwg
FIELD: control technologies in packet telecommunication networks and data transfer networks.
SUBSTANCE: method is based on shortening down to minimal separate list (INS) of number of clients subject to control due to maximal statistical relations of data exchange inside network node in comparison to number of analogical network nodes in whole network, and also maximal productiveness of network node and during control input data packets are compared only in portion of address of incoming data packets with minimal separate list of number of clients subject to control, while received minimal separate list of number frequency clients subject to control is used for verification of each passing data packet.
EFFECT: decreased work amount of processor providing control over communication participants, while main problem is large number of relatively short data packets, which is necessary to compare to full, related to whole network, list of client inputs subject for control, and productiveness of computing devices connected thereto, which is necessary in each node for realization of this problem.
4 cl, 2 dwg
FIELD: method and device for measuring quality of signal shape.
SUBSTANCE: real signal, representing shape of signal, divided on separate channels by time and codes, is produced, for example, by means of standard communication system for high speed data transfer. Controlling-measuring equipment produces ideal signal shape, matching real signal shape. This equipment produces estimate of shifts between parameters of real signal shape and ideal signal shape, then performs estimation of different measurements of quality of signal shape using quality measurements of compensated real shape of signal. Examples of processing real signal shape and appropriate ideal signal shape by means of controlling-measuring equipment are given. Provided method and devices can be utilized with any shape of signal, separated on channels by time and codes, not depending on equipment, which produces signal shape.
EFFECT: increased precision of measurement of signals shape quality, which are separated on channels in temporal area and code area.
3 cl, 3 dwg
FIELD: communications engineering, possible use for classification of connections.
SUBSTANCE: in method and device by means of computing block one or several distance coefficients are determined, while distance coefficients show efficient length of network connection depending on distance by air. On basis of known data about network connections, distribution coefficient of weak portions is determined, showing mutual relation to each other of weaker portions of network connection. Data transfer resource is determined to determine maximal for data transfer capacity for different types of modems. On basis of efficient length of network connection, weaker portions distribution coefficient and data transfer resources by means of computing block classification is performed (of subject network connection in accordance to its maximal data transfer capacity).
EFFECT: possible quick and flexible determining of service quality parameters.
3 cl, 9 dwg