SU1317676A2 - Device for tracking delay of noise-like signals - Google Patents

Description

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The invention relates to radio engineering and can be used in radio systems that process noise-like signals and is an improvement of the invention according to the authors. with. No. 498748.

The aim of the invention is to improve noise immunity.

FIG. 1 shows a structural electrical circuit of a device for monitoring the delay of noise-like signals (PSS) and an embodiment of a discriminator; figure 2 - option re-Livadia shaper weighting factors; on fig.Z and 4 - characteristics of the discriminator and the correlator of the torus

The PSS delay tracking device contains a discriminator 1, the first adder 2, the decisive block 3, the correlator 4, the second adder 5, the control block 6, the register, the 7 reverse shift, the delay block 8, the multiplier 9 block, the driver 10 weighting coefficients), a tunable oscillator 11 clock pulses (TI) and an error dispersion meter 12, the discriminator 1 contains multiply. 13, the amplifier 14 and the low-pass filter 15, and the VC driver 10 has a constant control unit 16 this storage device (ROM) 17 and digital tax converter (DAC) 18.

The tracking device for the lateral PSS operates as follows. , The device receives a pseudo-random signal (SRP), which is to be monitored. The SRP, which coincides in structure with the input signals, generates a shift register 7, at the outputs of which and at the outputs of the delay block, at each instant of time, the SRP delayed one relative to another for the duration of one character is output. The reference signal for discriminator 1 is generated as follows. The SRP taken from each tap of the delay block 8 and from the C of the N bits of the shift register 7, shifted from one another by the duration of one character, goes to block 9 of multipliers, where each SRP is multiplied with a certain weights (1m coefficient, then these CRPs arrive at the inputs of the first adder 2, on

6 2

the output of which forms the reference signal of the discriminator 1, arriving at the second input of the discriminator 1. By changing the values of the weight coefficients, it is possible to obtain discriminatory characteristics of various types (Fig. 3). The weighting factors are stored in the memory cells of the ROM 17 of the driver 10 VC.

The correlator 4 forms at its output the characteristic of the view shown in FIG. 4. In this case, the input signal is fed to the first input of the correlator 4, and to the second input

the reference SRP is received, which is formed by summing the SRP taken from each of the N bits of the shift register 7 and each tap of the delay block 8, in the second adder 5. As a result, the above characteristic is formed at the output of the corrector 4 (Fig. 4) . I

The synchronization process is carried out in two stages. At the first stage, the maximum of the characteristic formed at the output of the correlator 4 is searched. At this stage, the magnitude of the voltage is compared.

at the output of the correlator 4 with the first set threshold of the decision block 3, and as long as this voltage does not exceed the set threshold, at the first output of the decision block 3 O.

in block 6 of the control, the pulses are subtracted from the TI sequence, thus a discrete tuning of the clock frequency of the shift register 7 occurs. Once

the voltage value at the output of the correlator 4 exceeds the first set threshold, 1 is generated at the output of decision block 3, and the first synchronization stage ends. System

switches to the exact synchronization mode. The voltage at the output of the error dispersion meter 12 is compared with the second selected threshold of the decision block 3. As soon as the voltage at the output of the error dispersion meter 12 exceeds the second set threshold of the decision block 3, at its second output, 1 is formed, which is fed to the input of the generator 10 VC, where the values of the weighting factors change, since the reading is carried out from other memory cells of the ROM 17. At this point, the switching occurs

discriminatory characteristics from type A to type B (fig.Z). The step of adjustment of the shift register 7 at precise synchronization within the limits of the discriminatory characteristic is determined by the tunable generator 11 TI by the magnitude of the voltage at the output of the discriminator 1.

Claims (1)

Invention Formula The tracking device for the delay of noise-like signals by auth.St. 498748, characterized in that, in order to increase noise immunity, serially connected shaper weights / b are introduced five  ABOUT 176764 the multipliers and a tunable clock pulse generator and error dispersion meter, the discriminator output is connected to the input of the decision block via an error dispersion meter and to the auxiliary input of the control unit via a tunable clock generator, the auxiliary output of the decision block is connected to the input of the weighing unit coefficients, and the outputs of the corresponding bits of the shift register with feedback and the outputs of the delay block are connected to the corresponding input s of the first adder through the multiplier block. 15 77 with 18 -aSfN-n} -0.5 (fJ-l} -0.5 asfN-l} 0, 0.5 Fi9. fieL Compiled by V. Evdokimova Editor K. Voloshchuk Tehred V. Kadar Orrector L, Peel s1 ;; 1Г2437 / 5Г draw 638 Subscription VNIIPI CCti State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab ,, d.4 / 5 Production printing company, Uzhgorod, Projecto st., 4