SU1700759A1 - Method for demodulation of signals with relative phase-shift keying with number of phase positions equal to two - Google Patents

Description

(21) (22)

(46) (72) (53) (56)

Number 47

4688886/09

03.05.89

12.23.91.

L.I. Smirnov

621.394.662 (088.8)

Petrovich NT Transmission of discrete information in channels with phase shift keying. - M .: Soviet radio, 1965, p.83.

(54) METHOD OF DEMODULATION OF SIGNALS WITH RELATIVE PHASE MANIPULATION WITH A NUMBER OF POSITIONS OF PHASES EQUAL TWO (57) The invention relates to electrical communication. The purpose of the invention is to increase the frequency range of the demodulation signals. The essence of the proposed method is that the oscillations generated from the input signal transform into two traveling hypersonic volume waves, the superposition of which, with a zero phase difference between the oscillations at the input of the radiating system of piezoelectric transducers, is equivalent to a focused hypersonic field, and with a phase difference of plus or minus equivalent to the flow rate of the hypersound, then the acoustic oscillations in the focusing area of the hypersound are converted into electrical oscillation, while control of the focusing mode and defocusing is carried out by changing the phase distribution of the wave front on the surface of the system of piezoelectric transducers arranged in Fresnel zones. 1 il.

The invention relates to telecommunications and can be used in discrete information transmission systems.

The purpose of the invention is to increase the frequency range of the demodulation signals.

The drawing shows a diagram of the piezoelectric transducers of the radiating system.

The diagram shows the conduit 1, the first 2, and the second 3 systems | we are radiation and transducer 4. The method is carried out as follows

From the received signal S (t), two coherent phases are formed at the intermediate frequency CO or at the carrier signal.

zomanipulated vibrations. One of the oscillations is delayed by about, relative to the other oscillation e (t). The delay time C, the oscillation e (t − i,), is chosen to be less than the duration of the elementary signal transmission. The delayed phase shift of CO С between e (t) and e (t-t-i) arising during the delay is set to equivalent radians (or zero). Then the phase C, .., + IT (or Cp) oscillations e (t-ЈO at the output of the delay channel corresponds to the phase cf; oscillations e (t) at the output of the direct channel. The AtjKO phase difference between these oscillations is experienced at each interval of duration intermittent changes (manipulation), taking the value of C); - Wed; .., - ft (or c /;

about about 1

SL

WITH

-tPu,) for

/ °

(.or zero) during

V

The e (t) and e (t-CO) oscillations thus formed (using two independent systems to transform piez electric converters) into two running hypersonic bulk waves. The first oscillation e (t) with the phase If; is fed to the input of the first system 2, and the second oscillation e (t-CO with phase, + 1G (or lf) - to the input of the second system 3. The output of the first (second) system is a hypersonic wave emitted from the surface 8 (from the surface Sj). e (t), e (t-Јi) on the surface of SV Sa corresponds to the complex amplitude A (,,) (0t of the hypersonic wave, where (, Ј) is the coordinate The points of the surface of the SVS, t are the time. The piezoelectric converters of the first system 2 are arranged symmetrically to the piezoelectric transducers of the second system 3 relative to their plane of separation. , 8 (p) symmetric pairs of transducers formed the n-th Fresnel zone of the hypersound wave surface in the 0Ј plane, where n is the number of the transducer and n 0,1,2, ..., N;

N

 U S (P), S;

N

U s,

(P)

The transducers inside each system (2 and 3) are electrically connected to 4Q so that oscillations in even Fresnel zones are always in antiphase oscillations in odd-numbered Fresnel zones.

4b

Hypersonic waves from the surface

N

U

tl-0

S2 (n);

N

- and

S, (n)

overlap one another due to diffraction divergence. The superposition of these waves, propagating in the sound pipe 1, during time T reaches the plane XOY of the receiving piezoelectric transducer 4, where the complex amplitude of the hypersound takes the value A (x, y;, lli-i) expf j (0 (t-T)}

Wave propagation process performs analog Fresnel transform

X

A (x, y; cf,,. () -Zf JI + - H («)

+ If A (;, Cf;.,) E; Krdrd ,, (1) SjW g „nilz

  + (x-p "+ (y-f) 2)

Where

 VT; TO

2ft

B

CO V

 JV, V - wavelength and speed of hypersound, respectively.

For the sake of brevity, non-essential factors are not indicated in the transform (1), including exp {j (j) tl

I accept wave A (x, y; C); , Cf,.,) Exp ЈjG3 (t-T) j transform converter 4 into electrical oscillation

A (Cf,,.,) Exp (jW (t-T)}

with amplitude

Aftfi.lfi-,) JI A (x, y; Cf;, q) .M) dxdy (2)

where S is the receiving transducer surface.

The latter is set so that the plane of symmetry 8l and S 5 is the plane of symmetry 8.

By virtue of the smallness of S2,83,84, relative to L, the decomposition of g in small parameters JT / L, H / fl, x // D, y /%, transform.

Call (1) can be written in the form N

A (x) Y; Cp;,. () 2 f (J +

and- fm

+ {f A (u ,, q)). (ffu "-

and)

Р -, - «A expljCw2 J t

2t -C- v) S J

dndv.

where and - -; v -

e

Yes

1700759

S (n) - Sj (n) - and the surfaces of piezoelectric transducers with noer n in systems 2 and 3, recorded with coordinates (u, v).

With a phase difference & CCP Cfj wasp 5 pr 1ka for xo 10 but in t. 5 o Opo ek on ho

., and O between e (t) and e (t -i) distribution of A (u, v; C) - (,,) on

Sl U S- (n) is symmetrical to the distribution - 1 nrV

A (u, v; If;,.) by S%

M, U Si (p)

and waves emitted from

these surfaces in the direction of the normal to EJЈ U S, are in phase with S and counter-faeno outside of it, i.e. the radiated superposition of the waves is focused at 84 and, after transformation (2), has a maximum amplitude A (tfj, () for s. With a phase difference h, (5 -Cfj

± 1Г between e (t-c) the distribution of A (u, v; CP;, C,) on S. is antisymmetric with the distribution of A (u, v;; (| 5.,) On Sj and the waves emitted from these surfaces in normal direction

si u s

:,. u o., they are folded in antiphase, i.e. radiated superposition of waves diverges. Then on S. the distribution A (x, y; C |; sM i-t) of the divergent wave has a minimum. For this reason, the transformation (2) gives a minimum amplitude A (CP {, C ,,).

Thus, the sequence of transformations (operations)

re (L), e (sl

H

 }

) - (1) - (2)

0

five

performs demodulation of the signal, converting the jumps of the difference (C || -C,) of the phase between the elementary messages of the signal into electrical pulses of the duration of Su, and the transition state between sprinkling without jumps to the intervals between these messages i.e. It displays electrical oscillations with an amplitude at the level of the internal noise of the demodulator itself. 5 The described sequence of transformations corresponds to the value of OJi-g. equivalent to. The selection of a phase shift equivalent to zero at the output of the demodulator corresponds to a time sequence, which is obtained from the described operation of inverting the amplitude of the output

signal.

Claims (1)

Invention Formula A method of demodulating signals with relative phase shift keying with a number of phase positions equal to two, according to which a delayed signal is formed relative to the input signal and 0 changes the phase of the generated signal, characterized in that, in order to increase the frequency range of the demodulation signals, the input signal and the signal with the changed phase 5 are converted into two hypersonic vibrations, two hypersonic vibrations are added and the total hypersonic oscillations are converted into an electrical signal .