RU2613923C1 - Method for forming interference resistance signals - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: method of forming the interference resistance signals is based on forming a broadband signal, for which the range expansion is used by the pseudo-random sequence, which is modulated by the wavelet-functions, wherein the modulation of the logic elements "1" and "0" of the pseudo-random sequence is performed by the appropriate wavelet-functions different from one another in the derivative order of the Gaussian function.

EFFECT: improving interference resistance of the radio signal in the communication systems by increasing the bandwidth of the frequencies occupied by it.

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Description

The invention relates to radio engineering and can be used to improve the noise immunity of radio signals (PC) in communication systems.

A known method of forming noise-like radio pulses for transmitting binary symbols of information with complex signals [patent RU 2231924 C1 of 06.27.2004]. The invention relates to information transmission systems and includes a minimum code-frequency modulation of the carrier frequency by summing the amplitude and phase modulated oscillations of quadrature channels, the modulating code sequences of which are obtained by recoding the code sequence of noise-like radio pulses, gating the resulting amount with a video pulse equal to the length of the code sequence, generating the opposite signal by inverting the code modulating code sequence of one of vadraturnyh channels.

The disadvantage of this method is the complexity of its implementation, associated with the need to form quadrature channels. In addition, the specified method employs an energetically non-optimal signal-code design, including amplitude-phase modulation, which reduces the effect of increasing noise immunity.

A known method of forming and processing a complex signal in noise-protected radio systems [patent RU 2205496 C1 of 05.27.2003]. The claimed invention relates to the field of radio engineering and includes phase manipulation of the carrier oscillation of the SRP and the information signal, on the receiving side, the removal of the SRP with subsequent demodulation in the Costas circuit, and a modified band noise is used as the carrier oscillation.

The disadvantage of this method is that increasing the stealth of the transmitted PC is achieved by reducing the noise immunity of the radio receiver.

A known method with increased noise immunity and high speed data transmission [patent RU 2334361 C2 from 05.15.2006].

The disadvantage of this method is the complexity of synchronization, since the signal implemented in it is an ultra-wideband pulse signal. And in ultra-wideband systems, the expansion of the spectrum occurs due to a decrease in the pulse duration up to several picoseconds.

The closest analogue in technical essence to the claimed one is the method of generating noise-resistant signals [patent RU 2412551 C2 from 02.20.2011]. In the analogue method, biorthogonal wavelet functions are preliminarily formed, then a numerical PSP is set, which is modulated by binary phase manipulation, while “0” and “1” are modulated by opposite biorthogonal wavelet functions.

The disadvantage of the closest analogue is the relatively low noise immunity associated with an insufficient increase in the PC bandwidth modulated by the biorthogonal wavelet function, compared with the PC bandwidth modulated by binary phase shift keying.

The purpose of the claimed technical solution is to develop a method for generating noise-resistant PCs, which provides increased noise immunity of the radio signal in communication systems by increasing the bandwidth occupied by it frequencies.

This goal is achieved by the fact that in the known method of generating noise-tolerant signals based on the formation of a broadband signal, for which the spread spectrum is used by the SRP modulated by wavelet functions, and the wavelet functions used to modulate the SRP are derivatives of various orders of the Gaussian function .

Thanks to the new set of essential features in the claimed method, the noise immunity of the signals is improved due to the use of wavelet functions of various orders of the Gaussian function when modulating the SRP.

In addition, the inventive method allows to achieve a significant increase in the bandwidth of the modulated signal due to the use of wavelet functions of various orders of the Gaussian function when modulating the PSP. The inventive modulation method also allows to increase the noise immunity of the signal in proportion to the increase in bandwidth, since the signal base increases.

The signal base is the product of the effective value of the signal duration and the effective value of the width of its spectrum [see S.I. Baskakov. Radio circuits and signals. M .: "Higher School", 2nd ed., 1988, 446 p.].

The claimed method is illustrated by drawings, which show:

in FIG. 1 - numeric binary PSP 1010010100, formed using a random number generator;

in FIG. 2 is a temporal representation of a signal constructed based on a function of a first derivative of a Gauss function;

in FIG. 3 is a temporal representation of a signal constructed based on a function of the eighth derivative of a Gauss function;

in FIG. 4 is a spectral representation of signals (modules) generated on the basis of the first and eighth derivatives of the Gauss function;

in FIG. 5 is a temporal representation of a signal generated by modulating the numerical binary SRP shown in FIG. 1, by signals based on the first and eighth derivatives of the Gaussian function;

in FIG. 6 is a temporal representation of a signal generated based on signals of a biorthogonal wavelet function and its opposite copy;

in FIG. 7 is a signal spectrum (module) generated by modulating a numerical binary SRP shown in FIG. 1, by signals based on the first and eighth derivatives of the Gaussian function;

in FIG. 8 is a spectrum of a signal (module) generated by modulating a numerical binary SRP shown in FIG. 1, by signals based on the biorthogonal wavelet function and its opposite copy.

The implementation of the claimed method is explained as follows.

p. 1. Preliminarily set a numerical binary SRP.

A numerical binary SRP can be set, for example, using a random signal generator. Random signal generators are known and described, for example, in RF patent No. 2168260 dated 05/27/2001.

As an example in FIG. 1 shows a numerical binary PSP 1010010100 formed using a random number generator.

p. 2. The values of zeros and ones are modulated by pre-formed wavelet functions, which are derivatives of various orders of the Gaussian function.

High order derivatives of the Gaussian function are known (see Internet: Topic 20. Wavelet Properties http://podelise.ru/docs/index-25329097.html, 07/22/2012). Each subsequent derivative increases the number of oscillations. At the same time, the duration of the wavelet itself is preserved, which allows for clock synchronization in the processing of the resulting broadband signals.

As an example explaining the technical result of spectrum expansion, modulating signals based on the first and eighth derivatives of the Gaussian function were selected for modulation of the SRP.

In the inventive method, signals based on wavelet functions representing derivatives of any, i.e. different orders of the Gauss function. If, for example, a logical “0” in the PSP is modulated by a wavelet function of one order, then a logical “1” should be modulated by a wavelet function of a different order. The choice of the order of the derivative of the Gaussian function can be any, but different for “0” and “1”.

As an example in FIG. 2 shows a temporal representation of the signal S1 (t) constructed on the basis of the function of the first derivative of the Gauss function, and in FIG. 3 is a temporal representation of the signal S0 (t) constructed on the basis of the function of the eighth derivative of the Gauss function.

Functions of high order derivatives of the Gauss function are known. The principle of their formation is described, for example, in [N.M. Asafiev. Wavelet Analysis: Fundamentals of the Theory and Application Examples // Uspekhi Fizicheskikh Nauk, vol. 166, No. 11, 1996, p. 1152]. Signal formation based on wavelet functions, which are derivatives of high orders of the Gaussian function, are known, see, for example, patent RU 2334361 C2 of 05.15.2006 and the Internet: Topic 20. Wavelet properties http://podelise.ru/docs/index -25329097.html, 07/22/2012.

сигналов:

- сигнала, сформированного на основе первой производной функции Гаусса;

- сигнала, сформированного на основе восьмой производной функции Гаусса.The use of wavelet functions, which are high-order derivatives of the Gaussian function, for modulating the PSD, leads to an increase in the frequency band occupied by the generated signal and thereby allows to increase its signal base. In turn, an increase in the signal base leads to an increase in its noise immunity. As an example, in FIG. 4 shows the spectrum modules

signals:

- a signal formed on the basis of the first derivative of the Gauss function;

- a signal formed on the basis of the eighth derivative of the Gauss function.

p. 3. Modulate the values of zeros and ones in the SRP wavelet functions, which are derivatives of higher orders from the Gauss function.

Modulation procedures are known, for example [see patent RU 2412551 C2 of 02.20.2011].

As an example, in FIG. Figure 5 shows the signal Z (t) generated by modulating a numerical binary SRP with wavelet functions based on derivatives of various orders of the Gaussian function. Units modulate the S1 (t) - signal based on the first derivative of the Gauss function, and zeros modulate the S0 (t) - signal based on the eighth derivative of the Gauss function.

Thus, an increase in the PC noise immunity is achieved as a result of increasing the bandwidth of the frequencies occupied by it, when using wavelet functions that are high-order derivatives of the Gaussian function as modulating signals. The indicated increase in the occupied bandwidth was obtained with respect to the signal V (t), formed by modulating the digital binary SRP (see Fig. 1) with the signals of the biorthogonal wavelet function and its opposite copy, used to generate noise-resistant signals in the closest analogue [patent RU 2412551 C2 dated 02.20.2011] (see Fig. 6).

- модуль спектра сигнала Z(t), сформированного путем модулирования числовой бинарной ПСП вейвлет-функциями на основе производных различных порядков от функции Гаусса. А на фиг. 8 показан

- модуль спектра сигнала, сформированного путем модулирования числовой бинарной ПСП, представленной на фиг. 1, сигналами на основе биортогональной вейвлет-функции и ее противоположной копии.In FIG. 7 is shown

- the spectrum modulus of the signal Z (t), formed by modulating the numerical binary SRP wavelet functions based on derivatives of various orders of the Gaussian function. And in FIG. 8 is shown

- the spectrum modulus of the signal generated by modulating the numerical binary SRP shown in FIG. 1, by signals based on the biorthogonal wavelet function and its opposite copy.

An analysis of the obtained spectra showed that in the inventive method, the bandwidth of a broadband signal modulated by wavelet functions based on derivatives of various orders of the Gaussian function, relative to a signal modulated by signals based on a biorthogonal wavelet function, is 1.4 times or 4 , 9 times compared to the bandwidth of a signal modulated by binary phase shift keying signals. In this case, the increase in noise immunity of the received signal is proportional to the increase in the bandwidth [see patent RU 2412551 C2 of 02.20.2011].

Thus, thanks to a new set of essential features in the claimed method, when it is used, it is possible to achieve the indicated technical result - increasing the noise immunity of the broadband signal due to the use of wavelet functions based on derivatives of various orders of the Gaussian function when modulating the SRP.

Claims (1)

A method for generating noise-tolerant signals based on the formation of a broadband signal, which uses the expansion of the spectrum by the pseudorandom sequence method, which is modulated by wavelet functions, characterized in that the logic elements "1" and "0" of the pseudorandom sequence are modulated by corresponding wavelet functions that differ in each other from each other by the order of the derivative of the Gauss function.

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