SU1297238A2 - Autocorrelation meter of parameters of pseudorandom phase-shift-keyed signal - Google Patents

Abstract

This invention relates to radio. Additional to avt .. No. 921104. The purpose of the invention is to increase the accuracy of the -measurement with a change in the carrier frequency of the received signal. The device contains three blocks of 1, 10 and 20 multiplication, el-2 delay, band-pass filter 3, non-linear el-4, four filters 5, 7, 11 and 21 low frequencies, r-r 6 tuning speed, two meters 8 and 9 frequencies, valve 12, pulse counter 13, meters 14 and 15 of the signal base and the length of the parcels, arithmetic unit 16, registration block 17, two phase shifters 18 and 19, two quadrants 22 and. 23, an adder 24 and a square-root extraction unit 25. The goal is achieved by measuring the values of the parameters of the received pseudo-random phase-manipulated signal: the carrier frequency and the duration of the signal, as well as the duration and number of the elementary premises of which the signal is composed. 2 Il. with S and C figl

Description

The invention relates to radio communication, can be used for processing phase-shift keyed (FMN) signals in discrete information transmission systems, in combined systems and in radialocation, and is complementary to the main one by author. St. 921,104.

The purpose of the invention is to increase the measurement accuracy when the carrier frequency of the received signal is changed.

Figure 1 shows the structural electrical circuit of the autocorrelation meter for the parameters of a pseudo-random phase-manipulated signal; Fig. 2 shows timing diagrams explaining the operation of the meter.

The autocorrelation pseudo-random phase-shift keyed signal meter contains the first multiplication unit 1, delay element 2, band-pass filter 3, nonlinear element 4, the first low-pass filter (LPF) 5, the tuning rate generator 6, the second LPF 7, 8.9 frequency meters, and the second the multiplication unit JO, the third low-pass filter 11, the valve 12, the pulse counter 13, the signal base meter 14, the sending time meter 15, the arithmetic block 16, the registration block 17, phase shifters 18.19, the third multiplication block 20, the fourth LPF 21, quadrants 22, 23, amount Op 24 and block 25 taking the square root.

The meter works as follows.

Received pseudorandom FMN signal (FIG. 26)

N

(t) (t-k i,) cosaJ t,

-u, (t, .., ......, ....-,

where V, tO (., Tp is the amplitude, the carrier frequency and the duration of the signal;

 , fl t with О 5-L i - modulating F (t) | 0 with other t FUNCTION.

- (Fig.2A);

t, N is the duration and the number of elementary parcels that make up the signal of duration T. (Tj, N- t g) is fed to the first inputs of blocks 1, 10 multiplication, delay element 2, and phase shifter 18, the output of which is a signal

N

U, (t) IIV F (t-ktjcos (co t + 90) K .1

N

+ Е1 (t-kt)) t.

The magnitude of the delay tr, which is formed on the first output of the delay element 2, is varied according to a linear law with the aid of a generator 6, which amplifies a periodic sawtooth control voltage.

The delay t, resulting from the second output of delay element 2, is set constant / T,.,. The received FMN signal, previously delayed, is fed to the second inputs of the multiplication units 1.10.

in element 2 by magnitude respectively

N

And t- "

U, (t) Ujt-r,) Xi; VeFj (t-t)

0

five

0

five

0

five

0

-kTjCoscO Ct-T :,); U, (t) U, (t-s) IIv, F (t-4) k-1

-ktJCoscO Ct-tj),

About t. T.

To the second input of block 20 multiply

signal arrives - N

U (t) (t-t.) (T-o -t) (t-Trp-k 3 sina) (t-t,).

The result of multiplication in multiplication unit 1 are high-frequency-filled beats, which are pro-. go through the band-pass filter 3 and the non-linear element 4. Low-pass filters 5 and 7 are tuned to high-frequency filling, which is the carrier frequency above. FMN-signal, and the envelope, which is the clock frequency of the pseudo-random modulating function. The outputs of the low-pass filter 5 and 7 are connected to 8.9 frequency meters, to the second inputs of which the output periodically varying saw-tooth voltage is fed from the mouths of the 6. As a result, information about the value of the clock frequency is taken from the output of the frequency meter 8, and frequency meter 9 - the value of the carrier frequency x, the received signal.

The result of multiplying the signals Uj-Ct) and Uj (t) in the multiplication unit 10 and the signals) and U. (t) in the multiplication unit 20 are complex oscillations, of which low-frequency voltages 11 and 21 are drawn respectively

and „(t) u, i :: z: F (t-k) F (t-n4-5)

K-1 h-1

xcosoJ tj;

and

H2

(t) (t-ks) F (,) x

K-1 h-1 XSina) .tj,

 ,,

where V, jK V |;

K. is the transfer coefficient of the multipliers,

which in quadrants 22 and 23 are squared

N N

V (t) V) (t-k jFCt-nTg K: 1

-), g.

STL t) V El r: F (t-kt3) F (t-nt P K (

-G2) 251p2i) D,

r, the voltages U (t) and) acting on the inputs of the adder 24, the output of which is the voltage

and, (t) 4 G: ZIt F () F (t-nt3, .1

-Ca)

which enters the input of the Black 25, at the output of which a voltage is formed

and „(t) u, E: z: :( t-kT,) F (t-n

n, b

-h)

35

being a product (figd). Two identical modulating functions F (t) (fig.2a) and F (t-t,) (fig.2g), shifted in time by the amount of delay.

The number of negative pulses in the voltage U (t) is equal to the number of phase jumps of the received FMN signal, and the duration of the negative pulses is equal to the delay time T and does not depend on the duration of the elementary parcels T:. The voltage Un (t) (figd) from the output of the block 25 enters the valve 12, the output of which passes

Autocorrelation meter of pseudo-random phase-mapped signal parameters by aut. St. 30 No. 921104, characterized in that, in order to improve the measurement accuracy when the carrier frequency of the received signal is changed, a first phase shifter is inputted, the input of which is connected to the second input of the holder element, the second phase shifter connected in series, the third multiplication unit whose other input is connected with the release of the first phase shifter

l, a quarter low-pass filter and the first quad, and a chain of successively connected second quad, an adder and a square root extractor, connected between the output of a third of its lower filter and the input of the valve, while the output of the first quad is connected to each other

only negative pulses (fige). to the input of the adder, and the input of the second. These pulses are counted by a phase shifter counter connected to the output of a com 13- delay element.

The following relationship exists between the number of phase jumps m during the duration of 1 received FMN signal and the number of its elementary parcels:.

The number of phase jumps m, calculated by the counter 13, is fed to the input of the meter 14 of the signal base, where the base of the signal N is determined. Information about

the value of the clock frequency from the output of the meter 8 goes to the meter 15, where the clock pulses are generated (figv), which are used to determine the duration of the elementary packages J, the measured values of the signal base and the duration of the elementary. the links t are fed to the arithmetic unit 16, where the duration of the received signal is determined

T T with S

The measured values of N, T, t, CO are fed to the corresponding inputs of block 17, where they are recorded.

Claims (1)

Formula of Invention Auto-correlation meter for pseudo-random phase-manipulated signal according to aut. St. No. 921104, characterized in that, in order to improve the measurement accuracy when changing the carrier frequency of the received signal, a first phase shifter is inputted, the input of which is connected to the second input of the delay element, the second phaser connected in series, the third multiplication unit, the other input of which is connected to the output of the first phase shifter l, a quarter low-pass filter and the first quad, and a circuit of the second quad in series, the adder and the square root extraction block, is connected between the output of a third of its low-pass filter and the input of the valve, while the output of the first quad is connected to the other. Order 796/61 Circulation 639 Subscription VNIIPI USSR State Committee for inventions and discoveries. 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, st. Project, 4 Compiled by A. Seselkin Tehred A. Kravchuk Proofreader A. Ilyin