SU860333A1 - Device for searching pseudo-noise signals - Google Patents

Description

(54) SEARCH DEVICE FOR PSEUDO-DEAD SIGNALS

The invention relates to radio engineering and can be used in airborne and ground radio communication systems, radar and radio navigation systems using pseudo-noise signals. A search device for pseudo-noise signals containing serially connected input correlator, decisive unit, element And, waiting generator, prohibition unit and generator M is known. sequence, the clock generator is connected to another input of the prohibition block, and the generator output n is connected to the other inputs of the input correlator, decider and element And IRS research 11. However, the device has a low interference resistance and a relatively large search time. The purpose of the invention is to increase noise immunity and accelerate synchronization. To achieve the goal, a pseudo noise signal search device containing a series-connected input correlator, a decisive block, an AND element, a waiting generator. a prohibition unit and an M-sequence generator, a clock generator is connected to another input of the prohibition unit, and the output of the research period generator is connected to the other inputs of the input correlator, decisive block and element And a series-connected unit is input. the match, the counter, the decoder and the adder, as well as the recurrent sequence generator and the initial position setting block, the output of which is combined with another input of the M-sequence generator, the first input of the recurrent sequence generator and another counter input, is connected to the first input of the coincidence block an additional output of the decision block and to the second input is the output of the generator of the period of research, the outputs of the decoder are connected to the corresponding inputs of the waiting generator, the output of the prohibition unit connected to the second generator input of the recurring sequence, the outputs of which are connected through an adder to the additional input input correlator. In the drawing there is a ylok-diagram of the proposed search for pseudo-noise signals. The device for searching for pseudo-noise signals contains an input correlator 1, a decisive block 2, element 3, a generator 4 research periods, a front generator 5, a prohibition block 6, a clock frequency generator 7, an M-sequence generator 8, an initial position setting block 9, a counter 10 , a recurrent sequence generator 11, an adder 12, a decoder 13, and a match block 14. Device search pseudotumor signals works as follows. The initial position setting unit 9 at the moment of switching on generates a pulse, which sets the generator 8 of the M-sequence and generator 11 of the recurrent sequence to the mutually synchronous state 1, and the counter 10 to the zero state. The decoder 13, in the zero state of the counter 10, opens the adder 12 through one of its inputs, which receives a recurrent sequence with a megam period, and the input correlator 1 begins the mutual correlation function (ICF) between the input pseudo-noise signal and recurrent sequence. If the ICF value does not exceed the permissible threshold in decision block 2 for the time Td, then the pulse from the generator output and the period of research produces a reset of the input correlator 1 and the decision block 2. One MPeIIHo with this pulse passes through the AND 3 element, since The 1A output block output unit 2 has a high level on the yarn and starts the waiting generator 5, which generates a 1 pulse equal to the duration of one sample of the input pseudo noise signal. Impulse from the waiting gene

The rator 5 locks the prohibition block 6 and one clock pulse at the controlled input, does not pass to the inputs of the 8 M-sequence generator and the 11 recurrent sequence generator. Thus, shifts of the reference sequences are made on., One discrete relative to the primed noise pseudo-noise network.

The ICF value is then checked again for the time Tjj between the MoBbiM signal and the recurrent sequence with the minimum period and, if the ICF value exceeds the threshold of the decision block 2, then the high output level and the impulse the output of the generator 4 of the study period through the block 14 matches will go to the input of the counter 10. The ego pulse will change

If the MCF value of the threshold level is exceeded in decision block 2, the next pulse will be recorded in counter 10 through block 14 of coincidence. The value of the counter 10 is changed, and at the output of the decoder 13, the pulse of the alarm signaling that the search is over is indicated. With the help of this signal, a log has been connected to the generator of the M-sequence of the circuit tracking the delay of the received pseudo-noise signal

The technical and economic efficiency of the device consists in increasing the noise immunity and reducing the time taken to synchronize.

Claims (1)

Invention Formula A pseudo noise signal search device containing the 4 states of the counter 10 connected in series, and this in turn will cause the permit potential to appear at the other output of the decoder 13 and open the adder 12 via another input, and also change the potentials on the controlled signals. the inputs of the waiting generator 5. The input correlator 1 now through the adder 12 enters another recurrent sequence with a large period. The search for a correlation outlier in the second stage is done in the same way as in the first stage. The only exception is that the waiting generator 5 generates a pulse, the duration of which is equal to the period of the recurrent sequence of the first stage. This is necessary so that the 8 M-sequence generator and the recurrent sequence generator 11 change their phases by larger values compared to the first stage, when the ICF peak is not detected. As soon as the correlation peak is found in the second stage, the decoder 13 will transfer the device to the next stage. At the last stage, the decoder 13 connects to the input correlator to the torus 1 through an adder 12 an output of the generator 8 M-sequence. At this stage, the waiting generator 5 generates pulses, the duration of which is maximum and corresponds to the duration of the recurring sequence at the previous stage of the search. During the analysis time, at this stage, the ICF is calculated between the input 1 n 1m pseudo-noise signal and the reference M-sequence. If the ICF does not exceed the threshold in decision block 2, then the impulse from the generator 4 of the research period through the element I 3 is triggered by the waiting generator 5, the output signal of which reorganizes the phases of the generator 8. The M-series and the generator 11 of the recurrent sequence. With