SU919114A1 - Device for measuring quantization characteristic of pulse-code modulated signal receiver - Google Patents

Description

The invention relates to radio engineering and can be used to measure the quality indicators of digital transmission systems, in particular transmission systems with pulse code modulation (PCM).

A device for measuring the quantization characteristics of a receiver with pulse-code modulation is known, which contains a measuring signal generator and a bandpass filter, a switch and a level indicator 1 at the reception.

However, the known device has a long measurement time.

The purpose of the invention is to reduce the measurement time.

This goal is achieved by the fact that a device for measuring the characteristics of quantization of signals with pulse-code modulation, containing a measuring signal generator at a transmission, and a bandpass filter, a switch and a level indicator at the reception, are entered sequentially connected by a code combination analyzer, the first memory block, the first scaler, the second scaler and the peak detector, sequentially

the connected pulse generator, the first And element, the second And element, the reversible counter and the third And element, the fourth And element, the second memory block and the series connected analyzer of the measurement cycle end, the delay block and the third memory block, and the level indicator are made in the form of connected eta10 sensor signal and comparator, while the input of the analyzer code combinations connected to the output of the measuring signal generator, the input of which is connected to the output of the third unit

15 . the memory and the first input are a commator, the output and the second input of which is connected respectively to the input of the second memory unit and to the output of the third element I, the second input of the KOTopoi o is connected

20 with the output of the delay unit, the input of which is connected to the second input of the first element And, the output of which the fourth element And is connected to the second input of the reversible counter, the output

25 which is connected to the second input of the second scaler, the output of the bandpass filter is connected to the second input of the first scaler, and the output of the peak detector is connected to the second input of the Comparator, the first and second outputs of which are connected respectively to the combined second input of the fourth And element and the first input, home analyzer end of the measurement cycle and with the combined second input of the fourth element And and the first input of the analyzer end of the measurement cycle and with the combined second inputs and the second element and analyzer measurement cycle completion. The drawing shows a structural electrical circuit of the device to be offered. A device for measuring the quantization of the receiver of signals with pulse-code modulation contains on the generator a measuring signal 1, and on a receiver 2 PCM signals, an analyzer 3 code combinations, a band-pass filter 4, the first memory block 5, the first large-scale converter 6, reversible counter 7, second scale converter 8, pulse center 9, switch 10, second memory block 11, peak detector 12 third memory block 13, first ,, second, third and fourth elements And 14-17, respectively, block 18 back RJ .ki analyzer 19 completion of measurement cycle, the indicator layer 20, configured as a series-connected sensor 21 and the reference signal, the comparator 22. The device operates as follows. Code combinations coming from the output of generator 1 to the input of a PCM signal receiver 2 are simultaneously sent to the input of the analyzer 3. The code combinations correspond to the interlacing of neighboring quantum thresholds. As a result, harmonic oscillations arise at the output of the band-pass filter 4, the amplitude of which is proportional to the difference in neighboring quantization levels. The analyzer 3 analyzes the code combinations at the output of the generator 1. The first memory block 5 records what step size corresponds to the current value of the code combinations, and as the step size increases, inversely proportional to the transfer coefficient of the first mass-TT .- - ... ... ..- ..4 "h. v-. GO converter b, supporting on

its output in the case of an ideal quantization characteristic is a constant level of oscillations. The difference from the ideal values of the quantization levels is fixed by the reversible counter 7 as follows. The oscillation from the output of the first large-scale converter comes through the second large-scale transducer 8, the peak detector 12 to the first input of the comparator 22 to automate the measurement process.

Claims (1)

1. Kethermoul K.V. Principles of pulse code modulation. M, Sv z, .1974, p.226-228 (prototype).