RU53832U1 - SIGNAL DEMODULATOR WITH RELATIVE PHASE MANIPULATION - Google Patents

Abstract

The utility model relates to the field of coherent detection of signals with relative phase shift keying by 180 ° by the method of comparing polarities. The technical result is the elimination of single errors in the designed OFM _n signal. A significant difference of the claimed utility model is the introduction of structural elements and using phase inversion of even half-waves of the OFM signal _n at the output of a half-wave rectifier, this technical result is achieved.

Description

The utility model (PM) relates to the field of coherent detection of signals with relative phase shift keying (RPM) by 180 ° by the method of comparing polarities.

Known signal detectors OFMn by the method of comparing polarities, a description in various sources, for example in:

1. Petrovich NT "Transmission of discrete information in channels with phase manipulation" M .: Sov. Radio, 1965;

2. Gorelov G.V., Fomin A.F., Volkov A.A., Kotov K.V. "The theory of signal transmission in railway transport" M .: Transport, 2001.

By technical essence, the device closest to the utility model is described in the first source, which for this reason is taken as its prototype.

The prototype consists of a coherent signal detector with an absolute PSK at 180 ° (Pistolkors detector) with a PSK decoder at its output.

As is known, the reference oscillation in such an FMN detector at 180 ° has spontaneous phase jumps at 180 °, which is why units are taken as zeros and zeros as units, i.e. on the contrary, why this phenomenon is called the inverse operation of the detector. If these phase jumps by 180 ° take place inside the code combination, then they generate single errors at the output of the OFMn decoder.

The main disadvantage of the prototype are single errors due to spontaneous phase jumps at 180 ° of the reference oscillation within the code combination.

The technical result of PM is the elimination of single errors in the detected OFMn signal.

The essence of the PM lies in the fact that in this detector the reference oscillation is formed as a result of the phase inversion of the even half-waves of the OFMn signal at the output of the half-wave rectifier. Technically, this is realized through the introduction of a prototype electronic key, two inverters (analog and digital).

A significant difference between PM is the totality of the introduced elements and their relationships, because only they allow to exclude single errors in the detected OFMn signal.

PM is illustrated by drawings.

Figure 1 presents the structural diagram of the demodulator OFM _n , and figure 2 is a timing diagram explaining its operation.

The demodulator consists of a half-wave rectifier 1 with an active load, a square root extractor 2, a single vibrator 3, a pulse divider 4 times the pulse repetition rate, a delay line 5, a phase inverter 6, a phase detector 7, a narrow-band filter 8, an OFMn 9 decoder, an electronic key 10 Digital Inverter 11.

Blocks surrounded by a dashed line form a reference oscillator

The operation of the circuit is as follows.

The input OFMn signal (U _in (t) in FIG. 2) is fed to the information input of the phase detector 7 through the delay line 5 and to the input of a half-wave rectifier 1 with an active load. From the output of unit 1, the rectified signal U ₁ (t) (Fig. 2) is supplied to the contacts of the key 10: to contact a and directly to contact b through the analog phase inverter 6. The signal U ₆ (t) is shown in Fig. 2. Contacts g and b are interconnected and connected through a narrow-band filter 8 to the reference input of the phase detector 7. From the output of block 1, the signal U ₁ (t) enters block 2, where the square root is extracted from it to increase and sharpen the pulses of the signal U ₁ ( t) at zero so that a single-shot 3 is reliably triggered from them. The pulses U ₃ (t) from block 3 are divided in frequency by half in block 4, as shown in FIG. 2. These pulses are fed to the control input d of contacts a, b directly, and to the control input e of contacts c, d through digital inverter 11. At U ₄ {t} = 0, contacts c, d are closed (contacts a, b are open) and the reference input of block 7 receives a positive half-wave U ₆ {t}. When U ₄ () t = 1, contacts a, b are closed (contacts c, d are open at the same time) and the negative half-wave U ₁ (t) is supplied to the reference input of block 7. In this way, a harmonic reference oscillation is formed, which is filtered out from interference by the filter 8. Multiplying with the input OFMn signal in block 7, we obtain an alternating digital signal U ₇ (t) of the relative code, which is converted to the original code U ₁₀ (t) in the decoder OFMn 9. It is seen that phase jumps of 180 ° of the reference oscillation in this shaper are excluded in principle. This eliminated the single errors of the detected signal, which is the technical and economic effect of this PM.

Claims (1)

A signal demodulator with relative phase shift keying (OFM _n ), consisting of a phase detector with an OFM _n decoder at its output, a half-wave rectifier with an active load, connected to the detector input, a frequency divider 2 times, characterized in that an electronic key with two contacts, 2 inverters (phase analog and digital), narrow-band filter, square root extractor, single-shot, pulse divider 2 times, and the output of a half-wave rectifier is connected to the information the input of the first contact directly, and with the information input of the second contact through an analog bass reflex, as well as with the control input of the first contact through the square root unit, one-shot, frequency divider 2 times, the control input of the second contact is connected to the control input of the first contact through digital inverter, the outputs of the contacts are interconnected and connected to the input of the narrow-band filter, the output of the shaper is the output of the narrow-band filter.