SU1571780A2 - System folr transmission and reception of signals with simultaneous amplitude and frequency modulation - Google Patents

Abstract

The invention relates to communication technology, can be used in information transmission systems and is an improvement of the invention according to the author. N 1256219. The aim of the invention is to improve the quality of transmission and reception under conditions of a priori uncertainty in the frequency of the carrier oscillation within wide limits. The goal is achieved by introducing on the receiving side two bandpass filters 15, 16, a 90 ° 13 phase shifter, a source 11 of a reference coherent signal, a mixer 19, an intermediate frequency amplifier 20, a limiter 21, a third phase detector 26, a DC amplifier 23 and generator 24 controlled by voltage. By adjusting the variable phase shifter 28 at the second output, the components of the message can be compensated. 1 il.

Description

where UQ is the average amplitude; about (t) U4 (t) Ufll cosCoOoat).

(five)

xx, (t) (-) Z cos (+ (Z) 2) x2 (t)

....

515.717806

The multipass phase detector in the first P „„ „(Р) P„ „() f„ x. (T) + I, - chl (O +

From the NF I Si m lStu approximation equivalent to the multiplication of i i) body, for its output signal you can + G (S)

to write down

Denote by ty - the angle of phase rotation at U out rf (t) Kf: 0 (P) (Uorp (t) x output of variable phase shifter 27

-if tt ttg (or 28)

u2 (t)} rfr (P) {pr X ((t), - -H 10 9t-arctg -Ј-); wg arctgG-if)

dt + yL x. (t) dt + h (0 - cfryH (t) jЯ3M1Y3M2

about 2 (6)

and taking into account expressions (1) - (10) after

For the linearized phase filtration ring, at the output we obtain the frequency tuning expression with the astatism for the signal

first order, provided that G 2, P. -, m

retention band exceeds the width of U6bi (L | m. + cos W, + (,)

modulated signal spectrum on

receiver input, you can record for

phase tracking error of 20 g. sin (f d (p

+ + oCg (0 cos C; +.

,, dtp 1 (Ji, N Pr t

utf (t) dt J + 7f Xi + & By adjusting the alternate phase-shifting tel 27 you can achieve execution

(7) 25 conditions;

Taking into account the signals at the outputs of the phase (p + 1L

rotator 13 at 90 °:

Ua (t) - Uoa.cos (Qoit), 30 THAH -l | m + 4 / 81PL

U, (t) U02.sin (MMt) / 8) - x (t) ± n (t) + (f

+,

at the outputs of the first and second synchronous- Q "dt v A /

detectors 12 and 14, which in the first approximation can be considered to be components are compensated

by the multipliers, the signals will have messages x2 (t).

The following view is similar to the adjustment of the variable-phase-shifter 28 at the second output.

UebixcAi) (P) KcA t output apch (fc) x40 can compensate for the components

1 CSK K p -UoUotUoi messages x, (t). However, such a comp xU2 (t) j to .4-Ј.Ј, the setting of messages x4 (t) and x (t) is possible under the condition P Ј Pr or

) MP) ft1 + oi (t) + ° (t) + «$ g

 M7 M7

+ M, x, (t) + M2x4 (t) JJ.

Claims (1)

Invention Formula sag (t) (Pmt (P) Xa U 6Xx Lpch (t) x 5Q System for transmitting and receiving IK K K U U U signals with simultaneous amplitude / U (t) j and frequency modulation by author. St. No. 1256219, distinguished from 9 (P) P (P) fl + ci (t) + oi (t) + so that, in order to improve the quality of transmission and reception pch 55 under conditions of a priori + M, x4 (t) + M4xa (t) 1 -sin Г-§ х Xt) +, with the uncertainty of the frequency of the carrier L L h. wide fluctuations + - х (t) + - --1 -SA.itt.-Ua.y .. two strips were introduced to the receiving side, a dtJ 2out filters, phase shifter by 90 °, xx, (t) (-) Z cos (+ (Z) 2) x2 (t) .... U6bi (L | m. + Cos W, + (,)  d. sin (f d (p + + oCg (0 cos C; +. 715717808 The source of the reference coherent signal-frequency detectors, the output of the source and the series-connected reference coherent signal is a sub-mixer, an intermediate-key amplifier to the second input of the third phase-castot, a limiter, a third phase-wave detector and an input of the phase-rotation detector, a DC amplifier 90 °, the outputs of which are connected to a voltage controlled oscillator, to the additional inputs of the amplitude of which is connected to the first and frequency detectors, which are amps of the mixer, the second input to The thresholds are in the form of synchronous detec- tions, the input of the receiving side, JQrov, the outputs of which are connected to the input of the amplifier at the intermediate frequency multipliers of the multipliers are connected to the amplitude and inputs. filters.