RU2762244C1 - Device for receiving information from a computer network on a noise-like signal - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention relates to the field of radio engineering and can be used to receive a noise-like signal (NLS). The device for receiving information of a computer network via a noise-like signal contains a receiving antenna, a mixer, a heterodyne, an intermediate frequency amplifier, a search correlator made in the form of the first, second and third correlators, to the inputs of which the first, second and third generators of the phase-shift search signal are connected, respectively, a tracking correlator made in the form of the first, second and third correlators, to the inputs of which the corresponding first, second and third generators of the phase-manipulated tracking signal are connected, a demodulator, an information receiver, and also a synchronizer. The presence of search and tracking correlators and generators of phase-shift search and tracking signals controlled by a synchronizer ensures the operation of the device in two modes: search and tracking.

EFFECT: reduction in the time for establishing synchronization along the phase of the pseudorandom sequence of the received signal, improving control over the departure of the phase of the pseudorandom sequence of the received signal during coherent reception.

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Description

The invention relates to the field of computing and can be used in a wireless computer network on a noise-like signal (NLS).

Known device for receiving information of the communication system on the NLS [1]. However, this device uses relatively short pseudo-random sequences of constant length, which are Barker sequences, which does not sufficiently reveal the capabilities of the NLS to increase the communication range.

Known device for receiving information of a digital communication system with phase-shift keyed NLS [2]. This device provides low noise immunity of the information transmission channel due to the fact that it uses incoherent reception instead of coherent.

As a prototype, the closest in technical essence device for receiving information of a radiotelephone communication system with a phase-shift keyed NLS was chosen [2]. The prototype device allows for coherent reception and allows the use of pseudo-random sequences of various lengths to estimate the communication range.

Figure 1 shows a diagram of a prototype device, where it is indicated:

1 - receiving antenna;

2 - mixer;

3 - heterodyne;

4 - intermediate frequency amplifier;

5 - phase-shift keyed signal generator;

6 - correlator;

7 - synchronizer;

8 - demodulator;

9 - receiver of information.

In the known device, the output of the receiving antenna 1 is connected to the first input of the mixer 2; the output of the mixer 2 is connected to the input of the intermediate frequency amplifier 4; the output of the local oscillator 3 is connected to the second input of the mixer 2; the output of the intermediate frequency amplifier 4 is connected to the first input of the correlator 6; the output of the phase-shift keyed signal generator 5 is connected to the second input of the correlator 6; the output of the correlator 6 is connected to the input of the synchronizer 7, to the first input of the demodulator 8; the first output of the synchronizer 7 is connected to the input of the local oscillator 3, the second output of the synchronizer 7 is connected to the input of the phase-shift keyed signal generator 5, the third output of the synchronizer 7 is connected to the third input of the correlator 6 and the second input of the demodulator 8; the output of the demodulator 8 is connected to the input of the information receiver 9.

The prototype device works as follows.

The received signal from the output of the receiving antenna 1 is fed to the first input of the mixer 2, to the second input of which the signal from the output of the local oscillator 3 is fed. The operation of the local oscillator 3 is controlled by the synchronizer 7, which generates frequencies according to the customer's specifications and control signals. In mixer 2, the signal is transferred to the intermediate frequency and the received signal is transmitted to the input of the intermediate frequency amplifier 4. From the output of the intermediate frequency amplifier 4, the signal is fed to the first input of the correlator 6, which processes the received signal using the reference phase-shift keyed signal coming from the output of the phase-shift keyed generator. signal 5. Frequencies according to the customer's specifications and control signals for the correlator 6 and the phase-shift keyed signal generator 5 are generated by the synchronizer 7. The output voltage from the output of the correlator 6 is fed to the inputs of the synchronizer 7 and demodulator 8. The demodulator 8 converts the input voltage into an information message, which is fed to information receiver input 9. The operation of the demodulator 8 is controlled by the synchronizer 7, which generates frequencies according to the customer's specifications and control signals. Synchronizer 7, in the absence of synchronization, searches for a phase-shift keyed noise-like signal in time and frequency, and then maintains synchronism.

The disadvantages of the prototype device are the long time to establish synchronization in the phase of the pseudo-random sequence of the received signal, insufficient control over the phase deviation of the pseudo-random sequence of the received signal, leading to a prolonged restoration of synchronization in coherent reception due to the presence of only one correlator 6 and a phase-shift keyed signal generator 5.

The proposed invention is aimed at reducing the time for establishing phase synchronization of the pseudo-random sequence of the received signal, improving the control over the phase deviation of the pseudo-random sequence of the received signal during coherent reception due to the introduction of new elements.

This is achieved by the fact that a device for receiving information of a radiotelephone communication system with a phase-shift keyed NLS, containing a receiving antenna, a mixer, a local oscillator, an intermediate frequency amplifier, a second generator of a phase-shift keyed tracking signal, a second tracking correlator, a synchronizer, a demodulator, an information receiver, while the output of the receiving antenna connected to the first input of the mixer, the output of which is connected to the input of the intermediate frequency amplifier, the output of which is connected to the first input of the second tracking correlator, the output of which is connected to the first input of the demodulator, the output of which is connected to the information receiver, the ninth output of the synchronizer is connected to the input of the second phase-shift keyed signal generator tracking, the output of which is connected to the second input of the second tracking correlator, the third input of which is connected to the twelfth output of the synchronizer, the first output of which is connected to the input of the local oscillator, the output of which is connected to the second at the mixer input, the second input of the demodulator is connected to the twelfth output of the synchronizer, the fifth input of which is connected to the output of the second tracking correlator, the first, second and third generators of the phase-shift keyed search signal, the first, second and third search correlators, the first and third generators of the phase-shift keyed tracking signal are added , the first and third tracking correlators, while the outputs of the first, second and third generators of the phase-shift keyed search signal are connected to the second inputs of the first, second and third search correlators, respectively, the outputs of which are connected to the first, second and third inputs of the synchronizer, respectively, the eighth and tenth outputs of which connected to the inputs of the first and third generators of the phase-shift keyed tracking signal, respectively, whose outputs are connected to the second inputs of the first and third tracking correlators, respectively, whose outputs are connected to the fourth and sixth inputs m synchronizer, respectively, the second, third and fourth outputs of which are connected to the inputs of the first, second and third generators of the phase-shift keyed search signal, respectively, in addition, the output of the intermediate frequency amplifier is connected to the first inputs of the first, second and third search correlators, respectively, the third inputs of which are connected to the fifth , the sixth and seventh outputs of the synchronizer, respectively, the eleventh and thirteenth outputs of which are connected to the third inputs of the first and third tracking correlators, respectively, the first inputs of which are connected to the output of the intermediate frequency amplifier.

Figure 2 shows a diagram of the proposed device, where it is indicated:

1 - receiving antenna;

2 - mixer;

3 - heterodyne;

4 - intermediate frequency amplifier;

10, 11, 12 - the first, second and third generators of the phase-shift keyed search signal;

7 - synchronizer;

13, 14, 15 - the first, second and third search correlators;

16, 5, 17 - the first, second and third generators of the phase-shift keyed tracking signal;

18, 6, 19 - the first, second and third tracking correlators;

8 - demodulator;

9 - receiver of information.

In the device shown in FIG. 2, the output of the receiving antenna 1 is connected to the first input of the mixer 2; the output of the mixer 2 is connected to the input of the intermediate frequency amplifier 4; the output of the local oscillator 3 is connected to the second input of the mixer 2; the output of the intermediate frequency amplifier 4 is connected to the first input of the first search correlator 13, to the first input of the second search correlator 14, to the first input of the third search correlator 15, to the first input of the first tracking correlator 18, to the first input of the second tracking correlator 6, to the first input of the third tracking correlator 19; the output of the first phase-shift keyed search signal generator 10 is connected to the second input of the first search correlator 13; the output of the second generator of the phase-shift keyed search signal 11 is connected to the second input of the second search correlator 14; the output of the third generator of the phase-shift keyed search signal 12 is connected to the second input of the third search correlator 15; the first output of the synchronizer 7 is connected to the input of the local oscillator 3, the second output of the synchronizer 7 is connected to the input of the first generator of the phase-shift keyed search signal 10, the third output of the synchronizer 7 is connected to the input of the second generator of the phase-shift keyed search signal 11, the fourth output of the synchronizer 7 is connected to the input of the third generator of the phase-shift keyed search signal 12, the fifth output of the synchronizer 7 is connected to the third input of the first search correlator 13, the sixth output of the synchronizer 7 is connected to the third input of the second search correlator 14, the seventh output of the synchronizer 7 is connected to the third input of the third search correlator 15, the eighth output of the synchronizer 7 is connected to the input of the first generator phase-shift keyed tracking signal 16, the ninth output of the synchronizer 7 is connected to the input of the second generator of the phase-shift keyed tracking signal 5, the tenth output of the synchronizer 7 is connected to the input of the third generator of the phase-shift keyed tracking signal 1 7, the eleventh output of the synchronizer 7 is connected to the third input of the first tracking correlator 18, the twelfth output of the synchronizer 7 is connected to the third input of the second tracking correlator 6 and to the second input of the demodulator 8, the thirteenth output of the synchronizer 7 is connected to the third input of the third tracking correlator 19; the output of the first search correlator 13 is connected to the first input of the synchronizer 7; the output of the second search correlator 14 is connected to the second input of the synchronizer 7; the output of the third correlator of the search 15 is connected to the third input of the synchronizer 7; the output of the first generator of the phase-shift keyed tracking signal 16 is connected to the second input of the first tracking correlator 18; the output of the second generator of the phase-shift keyed tracking signal 5 is connected to the second input of the second tracking correlator 6; the output of the third generator of the phase-shift keyed tracking signal 17 is connected to the second input of the third tracking correlator 19; the output of the first tracking correlator 18 is connected to the fourth input of the synchronizer 7; the output of the second tracking correlator 6 is connected to the fifth input of the synchronizer 7 and to the first input of the demodulator 8; the output of the third correlator of tracking 19 is connected to the sixth input of the synchronizer 7; the output of the demodulator 8 is connected to the input of the information receiver 9.

The proposed device works as follows.

The received signal from the output of the receiving antenna 1 is fed to the first input of the mixer 2, to the second input of which the signal from the output of the local oscillator 3 is fed. The operation of the local oscillator 3 is controlled by the synchronizer 7, which generates frequencies according to the customer's specifications and control signals. In the mixer 2, the signal is transferred to the intermediate frequency and the received signal is transmitted to the input of the intermediate frequency amplifier 4. From the output of the intermediate frequency amplifier 4, the signal is fed to the first input of the first search correlator 13, to the first input of the second search correlator 14, to the first input of the third search correlator 15, to the first input of the first tracking correlator 18, to the first input of the second tracking correlator 6, to the first input of the third tracking correlator 19. The second phase-shift keyed search signal generator 11 and the second phase-shift keyed tracking signal generator 5 generate reference phase-shift keyed signals with the current phase of the pseudo-random sequence. The third phase-shift keyed search signal generator 12 and the third phase-shift keyed signal generator 17 generate phase-shift keyed signals with the phase of the pseudo-random sequence shifted one code symbol back from the current phase. The first phase-shift keyed search signal generator 10 and the first phase-shift keyed signal generator 16 generate phase-shift keyed signals with a pseudo-random sequence phase shifted one code symbol forward from the current phase. The first, second and third correlators 13, 14, 15 process the received signal using the reference phase-shift keyed signals coming from the outputs of the first, second and third generators 10, 11, 12, respectively. The first, second and third correlators 18, 6, 19 process the received signal using the reference phase-shift keyed signals coming from the outputs of the first, second and third generators 16, 5, 17, respectively. The device operates in two modes: search and tracking. At the initial moment of time, the device operates in the search mode, in which the phase of the pseudo-random sequence of the received signal is searched for to establish synchronization. In the search mode, at the moment of passing through the correlators 13, 14, 15, 18, 6, 19 of the entire length of the pseudo-random sequence of the received signal, the synchronizer 7 compares the voltage values at its inputs connected to the outputs of the first, second and third correlators 13, 14, 15 and the first , the second and third correlators 18, 6, 19, with a threshold value and among the voltage values equal to the threshold or exceeding it, finds the maximum. If at the output of the correlator 13 by the synchronizer 7 a maximum voltage equal to or exceeding the threshold value was detected, the bits of the registers of the generators 10, 11, 12 are shifted by one code symbol to the right, if at the output of the correlator 15, the bits of the registers of the generators 10, 11 are shifted, 12 one code symbol to the left, if at the output of the correlator 14 - the values of the bits of the registers of the generators 10, 11, 12 remain unchanged. After that, the resulting values of the registers of the generators 10, 11, 12 are assigned to the registers of the generators 16, 5, 17, respectively, the device goes into the tracking mode. If at the output of the correlator 18 by the synchronizer 7 a maximum voltage equal to or exceeding the threshold value was detected, the bits of the registers of the generators 16, 5, 17 are shifted by one code symbol to the right, if at the output of the correlator 19, the bits of the registers of the generators 16, 5 are shifted, 17 one code symbol to the left, if at the output of the correlator 6 - the values of the bits of the registers of the generators 16, 5, 17 remain unchanged. After that, the resulting values of the registers of the generators 16, 5, 17 are assigned to the registers of the generators 10, 11, 12, respectively, the device goes into the tracking mode. If all the values of the voltages at the inputs of the synchronizer 7 are less than the threshold, the values of the registers of the generators 10, 11, 12 are shifted by one code symbol to the right, and a new cycle of the search mode is started. In the tracking mode, at the moment of passing through the first, second, third correlators 18, 6, 19 of the entire length of the pseudo-random sequence of the received signal, the synchronizer 7 compares the voltage value at its fifth input, which is connected to the output of the second correlator 6, with a threshold value. If the value at the fifth input of the synchronizer 7 is equal to or exceeds the threshold value, this indicates that the phase synchronization of the pseudo-random sequence of the received signal and the pseudo-random sequence of the reference signal at the second input of the second correlator 6. In this case, the device operates synchronously with the received signal, a new cycle of tracking mode starts. If the value at the fifth input of the synchronizer 7 is below the threshold value, it is considered that there was a loss of phase synchronization of the pseudo-random sequence of the received signal and the pseudo-random sequence of the reference signal arriving at the second input of the second correlator 6. In this case, the synchronizer 7 compares the voltage values at its fourth and sixth inputs connected to the outputs of the first and third correlators 18, 19, respectively, with a threshold value and among the voltage values equal to or exceeding the threshold value, finds the maximum. If at the output of the correlator 18 by the synchronizer 7 a maximum voltage equal to or exceeding the threshold value was detected, the bits of the registers of the generators 16, 5, 17 are shifted by one code symbol to the right, if at the output of the correlator 19, the bits of the registers of the generators 16, 5 are shifted, 17 one code character to the left. It is considered that the phase synchronization of the pseudo-random sequence of the received signal has been restored, and a new cycle of the tracking mode is started. If the voltage values at the fourth and sixth inputs of the synchronizer 7, connected to the outputs of the first or third correlators 18, 19, respectively, are less than the threshold, it is considered that the phase synchronization of the pseudo-random sequence of the received signal could not be restored in the tracking mode, the device goes into the search mode. The voltage from the output of the second correlator 6 is supplied to the first input of the demodulator 8, which converts the incoming signal into an information message. The information message from the output of the demodulator 8 is fed to the input of the information receiver 9. By the operation of the heterodyne 3, phase-shift keyed signal generators 10, 11, 12, correlators 13, 14, 15, phase-shift keyed signal generators 16, 5, 17, correlators 18, 6, 19, demodulator 8 controls the synchronizer 7, which generates frequencies according to the customer's specifications and control signals. Also, the synchronizer 7 controls the operating modes of the device.

Sources of information

1. US patent No. 5077753, cl. H04L 27/30, 1991.

2. L.E. Varakin "Communication systems with noise-like signals", M., "Radio and communication", 1985, 384 p.

Claims (1)

A device for receiving information of a computer network on a noise-like signal, containing a receiving antenna, a mixer, a local oscillator, an intermediate frequency amplifier, a second generator of a phase-shift keyed tracking signal, a second tracking correlator, a synchronizer, a demodulator, an information receiver, while the output of the receiving antenna is connected to the first input of the mixer, the output which is connected to the input of the intermediate frequency amplifier, the output of which is connected to the first input of the second tracking correlator, the output of which is connected to the first input of the demodulator, the output of which is connected to the information receiver, the ninth output of the synchronizer is connected to the input of the second generator of the phase-shift keyed tracking signal, the output of which is connected to the second the input of the second tracking correlator, the third input of which is connected to the twelfth output of the synchronizer, the first output of which is connected to the input of the local oscillator, the output of which is connected to the second input of the mixer, the second input is demodulated ora is connected to the twelfth output of the synchronizer, the fifth input of which is connected to the output of the second tracking correlator, characterized in that the first, second and third generators of the phase-shift keyed search signal, the first, second and third search correlators, the first and third generators of the phase-shift keyed tracking signal , the first and third tracking correlators, while the outputs of the first, second and third generators of the phase-shift keyed search signal are connected to the second inputs of the first, second and third search correlators, respectively, the outputs of which are connected to the first, second and third inputs of the synchronizer, respectively, the eighth and tenth outputs of which connected to the inputs of the first and third generators of the phase-shift keyed tracking signal, respectively, whose outputs are connected to the second inputs of the first and third tracking correlators, respectively, whose outputs are connected to the fourth and sixth synchronization inputs respectively, the second, third and fourth outputs of which are connected to the inputs of the first, second and third generators of the phase-shift keyed search signal, respectively, in addition, the output of the intermediate frequency amplifier is connected to the first inputs of the first, second and third search correlators, respectively, the third inputs of which are connected to the fifth, the sixth and seventh outputs of the synchronizer, respectively, the eleventh and thirteenth outputs of which are connected to the third inputs of the first and third tracking correlators, respectively, the first inputs of which are connected to the output of the intermediate frequency amplifier.

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