SU794747A2 - Broadcasting channel parameter measuring device - Google Patents

Description

one

The invention is based on communication technology and can be used for automated measurements in discrete form of quality indicators of broadcast paths, including paths organized in high-frequency transmission systems.

According to the main author. St. N ° 641666 a device is known for measuring parameters of broadcast channels, on the receiving side there are serially connected matching unit, service signal processing unit and unit for switching measurement types, as well as serially connected filter unit, first attenuator, first amplifier, first detector, logarithm and unit registration, and the output of the switching unit of the measurement types is connected to the control inputs of the filter unit, the first attenuator and the logarithmic converter, attenuator block level calibration signals, a second amplifier, a second detector output matching block connected to an input of the second attenuator, the output of which is connected via a series-connected level calibration unit, filter unit, a second amplifier, a second detector to the second input of the logarithmic converter,

wherein the output of the switching unit of measurement types is connected to the control input of the second attenuator 1.

However, the known device has insufficient accuracy.

The purpose of the invention is to improve accuracy.

For this purpose, a device for measuring parameters of broadcast channels, comprising

on the receiving side, a serially connected matching unit, a signal processing unit and a unit for switching measurement types, as well as a serially connected filter unit, a first attenuator, a first amplifier, a first detector, a logarithmic converter and a registration unit, the output of the unit for switching measurement types connected to the control inputs block

filters, the first attenuator and a logarithmic converter, the second attenuator, the signal level calibration unit, the second amplifier, the second detector, the output of the matching unit is connected to the input

the second attenuator, the output of which is connected through a serially connected level calibration unit, a filter unit, a second amplifier, a second detector to the second input of a logarithmic converter, the output of the switching unit of the measurement type is connected to the control input of the second attenuator; a pulse counter and a counting pulse generator, while at the receiving side between the logarithmic converter and the registration unit are connected in series with first coincidence unity element, the other input of which is connected to the output of the generator counting pulses, and a pulse counter having an input connected to the output of the generator counting pulses through a second coincidence element, the other input of which is connected to the input of the logarithmic converter control and recording unit.

FIG. 1 shows a structural electrical circuit of the receiving side of the proposed device; in fig. 2-time diagrams of the device.

A device for measuring parameters of broadcast channels at the receiving side contains a matching unit 1, a signal processing unit 2, a measurement switching unit 3, a first attenuator 4, a signal level calibration unit 5, a filter unit 6, a second attenuator 7, a first amplifier 8, a first detector 9, the logarithmic converter 10, the first And match element, the pulse counter 12, the registration unit 13, the second amplifier 14, the second detector 15, the Second coincidence element 16, and the counting pulse generator 17.

The device works as follows.

From the transmitting side of the device, through the matching unit 1, a series of service signals is received in the signal processing unit 2, the parameters of which identify the measurement program. Depending on the type of measurements, a signal is formed in the switching unit 3 of the measurement types (Fig. 2a), which sets the first and second attenuators 4, 7 and the filter unit 6 to the position corresponding to this measurement. The time interval to the input of the receiving part of the device receives the measuring signal (Fig. 26) and the reference signal (fng. 2c), which are separated in the filter block b and pass through various circuits to the logarithmic converter 10. Nominal level of the reference signal at the input The logarithm converter 10 is determined by the first attenuator 4 and the signal level calibration unit 5, and the level of the measurement signal is determined by the second attenuator 7.

At time tz, a signal (rig. 2g) is received from the switching unit 3 of the measurement modes to the control input of the second element 16, which permits the passage of counting pulses from the generator 17 of counting pulses into the pulse counter 12 through the second match element 16. Duration - from the signal on the control input of the second element 16

5 coincidence is such that the number of pulses corresponding to the type of measurement passes into the pulse counter 12. The number of pulses recorded in the pulse counter 12 before the comparison of the measuring and reference signals during the time interval t (Fig. 2g) starts, takes into account the introduced level difference in the reference and measuring signals.

At the time of tz from switch 3 block

The jg of the measurement types to the control input of the logarithmic converter 10 receives a signal (Fig. 2e), with the arrival of which a comparison of the levels of the measuring and reference signals begins. At the output of the log, the Q of the rhymic converter 10 at the moment of 1h a signal appears (Fig. 2e), the duration of which is proportional to the logarithm of the ratio of the measuring signal to the reference signal. The signal from the output of the logarithmic converter 10 is fed to the first input of the first element 11 of the match and opens it. Through the open first element 11, matches from the generator 17 counting pulses to the first input

0 of the pulse counter 12, counting pulses are received, which are added to the number recorded in the pulse counter of 12 pulses earlier (Fig. 2g).

At time 4, from the switching unit 3 of the 5 measurement types, a signal is received at the control input of the recording unit 13 (Fig. 2h), by which the result obtained in the counter 12 pulses is recorded.

Claims (1)

1. USSR author's certificate number 641666, cl. H 04B 17/00, 1976 (prototype). 1 F 3