SU1467784A2 - Device for receiving phase-manipulated signals - Google Patents

Abstract

This invention relates to radio. The purpose of the invention is to expand the functionality. The device contains mixers 1-5, the reference rr. 6, low-pass filters 7-9, a phase shifter 10, controlled by rr-11, band-pass filters 12 and 13, a doubler 14 frequency, demodulator 15, blocks of phase-locked loop 16 and 17 frequencies, dividers 18, 19 and 22 frequencies, multipliers 20 and 23 and filters total 21 and differential 24 frequencies. The goal is achieved by providing reception of signals with a combined frequency and phase shift keying. 1 il. and

Description

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The invention relates to radio, can be used to receive discrete information transmitted by signals with a combined frequency and phase shift keying, and is an improvement of the invention by author. St. No. 1061285.

The purpose of the invention is to expand the functionality by receiving signals with a combined frequency and phase shift keying.

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

The device contains mixers 1-5, a reference generator 6, low-pass filters 7-9, a phase shifter 10, a controlled oscillator 11, the first 12 and second 13 band-pass filters, a frequency doubler 14, a demodulator 15, blocks 16 and 17 of the phase-locked loop, the first 18 and second 19 frequency dividers, the first multiplier 20, the total frequency filter 2, the third frequency divider 22, the second multiplier 23 and the difference frequency filter 24.

The device works as follows.

The received radio signal with a combined frequency and phase shift keying- (FMN-FMN) is analytically described by the expression

Uc {t) Uc. cos {2.4fcpt-f (pK),,

, 2,

where subscripts 1 and 2 for frequencies and phases correspond to symbols transmitted in the frequency and phase subchannels;

Uc - signal amplitude; fi fcp- - frequency corresponding to the symbol “+

4T

f, fcp + ±

- frequency corresponding to the symbol

T - the duration of the elementary parcels (character intervals);

- average signal frequency

The O (, 2) -manipulated phase component, which represents the law of phase manipulation, with cpK const at (gn - | -1) T, and can change abruptly at, i.e., at the boundaries between elementary premises (, 2 ..., N-1);

N is the number of elementary parcels from which the signal with duration Tc is composed (Tc N. T);

(t) +1, -1 sequence of information symbols

(modulating code), according to which the signal frequency is manipulated;

M2 (t) {-fl, -li - sequence of information symbols (OOD) code, in accordance with which the phase is manipulated

signal.

The specified signal is fed to the inputs of mixers 1 and 3 frequencies. Using the mixer 1 frequency, the reference generator 6 and the band-pass filter 12 is carried 5 transfer the spectrum of the radio signal to the middle frequency

,

where Get is the frequency of the reference generator signal 6.

0 Mixers of 2, 4, and 5 frequencies, low-pass filters 7–9, a controlled oscillator 11, and a phase shifter 10, performing a 90 ° phase shift, form a Costas ring designed to track

r suppressed carrier. In the spectrum of an FMN-FMN signal with a manipulation index

D (f2-f,), 5

character frequencies are suppressed. Therefore, the Costas ring monitors the “imaginary average frequency fcp, taking into account the instability

0 input frequency. If the absolute instability of the received signal ± b is greater than the spacing between the symbol frequencies (f2-f), then the passbands of the low-pass filters should be equal

...

Thus, the controlled oscillator 11, enclosed in a Costas ring, is a local oscillator with a frequency

1cr 1crTet

using a 3 frequency mixer and a band-pass filter 13, the spectrum of the received radio signal is transferred to the reference frequency

1et 1cp-fcp;

Iet (1) Iats05 (2l et1N-f),

.

With the help of heterodyning and the indicated Kostas loop property, the symbol frequency stability is significantly improved and determined by the frequency stability of the fsT of the reference oscillator 6. Therefore, the pickup bands of the phase locked loops 16 and 17 can be chosen narrow enough to eliminate the possibility of false hooks and hooks for one of the discrete constitutors. If the stability of the far frequency of the reference generator 6 is high, then a highly stable FMN-FMn signal is present at the input of the demodulator.

five

0

five

The frequency doubler 14, phase locked loops 16 and 17, and frequency dividers 18 and 19 form a symbol synchronization system necessary for coherent demodulation, which is performed in demodulator 15. Symbolic synchronization is based on the fact that in the energy spectrum of the FMN-FMn signal with the manipulation index, there are discrete components at the symbol frequencies fi and fg. The signal with the manipulation index is formed from the received FMN-FMN signal using a frequency doubler 14. With the help of blocks 16 and 17 of the phase-locked loop, discrete components are filtered, and frequency dividers 18 and 19 are designed to match the frequencies of the synchronization signal and the received signal.

At the outputs of the dividers of 18 and 19, the following harmonic oscillations are formed:

U: (t) Ui-cos2nf | t;

U2 (t) U2COS2nf2t.

The harmonic oscillations Ui (t) and U2 (t) from the output of the frequency dividers 18 and 19 together with the received signal from the output of the bandpass filter 13 go to the demodulator 15, from the output of which the double sequence of symbols MI (t) transmitted by frequency manipulation (FMN), comes to the recipient of information.

At the same time, the harmonic oscillations Ui (t) and U2 (t) from the outputs of the dividers 18 and 19 of the frequency arrive at the inputs of the multiplier 20, the output of which produces a voltage

U3 (t) U (t) - U2 (t) Vo-COS2n (f, + f2) t - «+ Vo- so52l (L - f,) t, where Ug,, V, - V2;

Ki is the multiplier transfer coefficient. The total frequency filter 21 is energized.

U4 (t) Vo-cos2n (f: + f2) t. The output of the frequency divider 22 is a voltage

U5 (t) Vo. cos2n () cos2nf3Tt,

, ef.lf-.

The harmonic voltage U (t) of the c-output frequency divider 22 is applied to the second input of the multiplier 23, to the first input

° of which the signal is given is iat (1). At the output of the multiplier 23, the following voltage is formed:

U6 (t) Vi-C05 (4l (et1 + fc) where Vo.

5 The discharge frequency filter 24 releases voltage.

Up (t) Vi-C05f,

representing a double sequence of characters transmitted by phase manipulation of the signal. This 0 voltage goes to the recipient information.

Claims (1)

Invention Formula 5 A device for receiving frequency-manipulated signals according to ed. St. No. 1061285, characterized in that, in order to extend the functionality by receiving a signal with a combined frequency and phase shift, serially connected first multiplier, total frequency filter, third frequency divider, second multiplier and differential frequency filter, whose output is additional output device, and the output of the first frequency divider is connected to the first input of the first multiplier, the second input of which is connected to the output of the second frequency divider, and the second input of the second multiplier is connected to the output of the second bandpass filter.