SU1197109A1 - Device for measuring probability of signal reception error - Google Patents

Abstract

DEVICE FOR MEASUREMENT. PROBABILITY OF ERROR. A SIGNAL RECEPTION containing a source of a carrier oscillation:, a pseudo-random sequence sensor, a phase manipulator, the control input of which is connected to the output of a pseudo-random sequence sensor, and a high-frequency input of the phase manipulator connected to the first output oscillator, successively connected oscillator and control emu attenuator, series-connected adder, band-pass filter, and automatic power control unit, demodulator, successor: but connected unit Neny and error counter vpsod automatic power control unit is connected to the data input of the demodulator, high-frequency input and output of which are connected respectively to the second, output power -. carrier and the first input of the comparator unit, the second input of which is connected to the output of a pseudo-random sequence sensors, characterized in that, in order to improve the measurement accuracy, a reference voltage source is introduced, connected in series to the first directional coupler, the input of which is connected to the output of the phase manipulator, and the first amplitude detector, the second directional coupler connected in series, the input of which is connected to the output of the controlled attenuator, and the second amplitude detector; detector, serially connected logarithmic voltage ratio meter and differential amplifier, the second input and output of which are connected respectively to the output of the reference voltage source and the control input of the controlled attenuator; the outputs of the first si and second amplitude detectors are connected respectively to the first and second inputs of the logarithmic voltage meter, the second output of the second directional coupler is connected to the first input of the adder, the second input of which is one with the output of the first directional coupler.

Description

one

. The invention relates to a technique for transmitting information and can be used to measure the probability of an error in receiving a signal prior to transmission over communication channels with noise.

The purpose of the invention is higher measurement accuracy. .

The drawing shows a structural electrical circuit of the proposed device.

A device for measuring the probability of a signal reception error includes a noise generator 1, an adder 2, a controlled attenuator 3, a first directional coupler 4, a pseudo-random sequence sensor 5, a phase keyer 6, a second directional coupler 7, the first 8 and second-9 amplitude detectors, logarithmic voltage meter 10 relative voltage, differential amplifier 11, reference voltage source 12, demodulator 13, band pass filter 14, block. 15 automatic power control, 16 oscillating source, block 17 comparison, 18 error counter.

The device works as follows.

 The signal coming from the carrier oscillation source 1.6 is phase modulated by a manipulator, phase 6, which is controlled by a pseudo-random sequence sensor 5. Part of the signal from the manipulator output

The 6 phase is branched off by the first directional coupler 4 to the input of the first amplitude detector 8, from whose output a voltage proportional to the signal power is fed to the first input of the logarithmic meter 10 of the voltage ratio. A part of the noise power output from the output of the noise generator 1 branches to the second directional coupler

7 and is fed to the input of the second amplitude detector 9, from the output of which a voltage proportional to the noise intensity is fed to the second input of the logarithm meter 10

09 2 stress ratios. A voltage proportional to the ratio of the signal power and noise from the output of the logarithmic meter 10 to the voltage ratio | 1 is fed to a differential amplifier 11, which compares this voltage with a predetermined threshold voltage, generated by the source 12, and generates an error signal that controls attenuator 3. As the signal power increases (due to temperature, temporary care, changes in supply voltages, etc.), the attenuation of the controlled attenuator 3 decreases, the noise power increases, and the signal-to-noise ratio remains constant. With increasing noise power, the feedback sign will be opposite, which will lead to an increase in attenuation of the controlled attenuator 3 and stabilization of the signal-to-noise ratio. In case not only stabilization of the signal-to-noise ratio is necessary, but also stability of the total power, the automatic power control unit 15 is used.

The signal and noise are summed up in the sum of the torus 2. The band-pass filter 14 is needed to form a test (total) signal in the desired frequency band. Due to the presence of interference in the received channel, the pseudo-random sequence at the output of demodulator 13 will be different1; from the transmitted one. The Blrk 17 comparison detects this difference, and the error counter 18 records the number of errors in a certain time interval. By changing the signal-to-noise ratio by changing the threshold, the noise immunity curve of the demodulator 13 can be removed.

The stability and accuracy of measurements in the proposed device are mainly determined by the parameters of the circuit that automatically adjusts the signal-to-noise ratio, therefore, further improvement of the device is possible by improving these parameters.

Claims (1)

DEVICE FOR MEASURING PROBABILITY OF ERROR. A SIGNAL RECEIVER containing a carrier wave source, a pseudo-random sequence sensor, a phase manipulator whose control input is connected to the output of the pseudo-random sequence sensor, and a high-frequency input of the phase manipulator is connected to the first output of the carrier wave source, a noise generator and a controlled attenuator, a series-connected adder, bandpass filter and. an automatic power adjustment unit, a demodulator, a comparison unit and an error counter connected in series, the output of the automatic power adjustment unit is connected to the information input of the demodulator, the high-frequency input and output of which are connected respectively to the second, output of the source ... carrier wave and the first input of the comparison unit the second input of which is connected to the output of the pseudo-random sequence sensor, characterized in that, in order to increase the accuracy of measurements, a reference voltage source is introduced the connections connected in series to the first 'directional coupler, the input of which is connected to the output of the phase manipulator, and the first amplitude detector, the series-connected second directional coupler, the input of which is connected to the output of the controlled § attenuator, and the second amplitude; detector, series-connected logarithmic voltage ratio meter and differential amplifier, the second input and output of which are connected respectively to the output of the reference voltage source and the control input of the controlled attenuator, the outputs of the first and second amplitude detectors are connected respectively to the first and second inputs of the logarithmic voltage ratio meter, the second output the second directional coupler is connected to the first input of the adder, the second input of which is connected to the output m of the first directional coupler.