RU2794517C1 - Discrete message transmission method and system for its implementation - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: technical result is to provide covert transmission with increased speed due to the absence of the need for signal synchronization. The method consists in the transmission of each element of the message by one of the broadband signal (BBS) ensemble. The system contains a converter of input discrete messages, a BBS generator, a communication channel, a matched filter, a decision device, and a shaper of output discrete messages.

EFFECT: covert transmission with increased speed.

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Description

Technical field

The invention relates to the field of radio engineering, computer technology and systems for noise-immune covert transmission of discrete messages in the presence of noise using a finite set of noise-like signals (NLS).

State of the art

A known method of transmitting information [1], in which the broadband carrier is a random process modulated by changing the multidimensional probability distribution function in accordance with the information signal. The received carrier at the receiving side is demodulated by measuring said multivariate probability distribution function. The disadvantage of this method is the lack of the possibility of energetically covert transmission of information and the lack of optimal detection and discrimination of signals in the presence (against the background) of noise (therefore, signal transmission is not ensured in an optimal way).

A known method of covert transmission of information [2]. The useful signal is converted into a binary code and the initial deterministic chaotic signal is formed by means of the first chaotic generator, the parameters of the chaotic signal are modulated by this useful digital signal. The received signal affects two chaotic oscillators, which are selected to provide generalized synchronization with the first chaotic oscillator. The useful signal disrupts the synchronization of one of the generators, which allows, after subtracting the signals of the first and second generators, to determine the presence of this useful digital signal. The signal of the first chaotic generator before transmission over the communication channel is added to the noise signal of the noise generator, which is significantly higher than the signal level of the chaotic generator itself. Energy secrecy is provided. The disadvantage of this method is the lack of the possibility of optimal detection and discrimination of signals in the presence of noise in an optimal way.

The method of secret transmission of information [3] differs from the method of [2] in that the characteristics of the noise generator are modulated by a digital or analog signal containing a false, insignificant or open information message. The disadvantages of the method are the same as those of the method [2].

A known method of transmitting and receiving discrete information signals [4]. The method implements the mapping of the symbols to be transmitted to the disturbance of the physical environment and the detection of these disturbances in the signal-noise mixture on the receiving side, as the generated disturbances, segments of periodic oscillations with a length equal to the length of the symbols transmitted through the propagation medium directly or used as modulating signals are used. On the receiving side, the signal-noise mixture is divided into sections, the pseudo-spectrum of the received sections of the signal-noise mixture is estimated, and in case of detecting a pseudo-spectral peak, a decision is made on the presence of a transmitted symbol in this section. The disadvantage of this method is the lack of the possibility of energetically covert data transmission over the communication channel, since the signals for pseudo-spectrum analysis on the receiving side must have a sufficient level. In addition, signal transmission is not ensured in an optimal way due to the lack of optimal detection and discrimination of signals in the presence of noise.

A coherent information transmission system is known [5]. A finite set of chaotic signals is used as a broadband NSS. The system contains transmitting and receiving sides. On the transmitting side, chaotic signals are formed, multiplied with the information sequence so that each bit is transmitted by its own segment of the chaotic signal, while synchronization of these signals is required on the transmitting and receiving sides. Copies of chaotic signals to extract the information sequence are formed from a disk on the receiving side. The secrecy of the structure of signals is provided. The disadvantage of analog is the need to ensure the synchronism of chaotic signals on the receiving and transmitting sides, which requires the use of signals of sufficient level, but this leads to a lack of energy secrecy of the system. Synchronization is also time consuming, which slows down the performance of the system, since it is necessary to use a wide spectrum NPN, but the wider the spectrum, the longer the acquisition and synchronization time. In this case, the coherence of the system means only the presence of synchronization of chaotic signals on the transmitting and receiving sides and does not provide optimal signal processing (detection and discrimination) in the presence of noise.

The prototype is a method for transmitting discrete messages and a system for its implementation [6, p. 16, 17]. The method consists in the fact that the information source (IS) generates at the input a sequence of pulses of duration G, corresponding to binary numbers ("1" and "0"), arriving at the input of the phase modulator, its second input with a period T receives the NPS in the form of a phase-shift keyed signal (FMS) of the same duration (represented by N=13 - Barker element code (KB)) from the FMS generator (its operation is controlled by the synchronizer). At the output of the phase modulator, KB are formed, and in the interval corresponding to the AI signal equal to "1", the FMS is not inverted by the phase detector, and in the interval where the AI signal is equal to "0", the used KB is inverted in phase. As a result, a sequence of NPSs is obtained in the form of KB (each of them is inverted or not), carrying information symbols. This sequence is fed to the modulator, which modulates the carrier oscillations that are generated by the low carrier frequency generator. The modulated oscillations are amplified in power and radiated into space (the physical medium of the communication channel).

At the receiver, the NPS sequence is transferred to the intermediate frequency using a mixer and a local oscillator, after which it is amplified. To implement synchronous reception, the FMS is searched for by frequency and time of arrival of signals, and signals are accumulated to ensure stable synchronization. For this, a matched filter (SF), a synchronizer and a resolver are used. It is noted that the specified NPS receiver with a large base is a complex device and the acquisition of synchronism requires the expenditure of a time interval depending on the NPS base. After the end of the search and entering into synchronism, an information sequence is formed in the form of binary symbols, which is transmitted to the output, the recipient of information (PI).

The system contains in the transmitter an information source, a phase modulator, an NPS generator in the form of an FMS, a synchronizer, a modulator, a low-frequency generator, a power amplifier, a communication channel. The receiver includes a mixer, local oscillator, intermediate frequency amplifier, SF, resolver, synchronizer, PI.

The system in the prototype is built and operates on the basis of the described method. From AI, the first input of the phase modulator receives an information sequence of binary "1" and "0", and the second input receives the FMS from the generator controlled by the synchronizer C ₁ (it generates control signals). The generator creates a NPS sequence in the form of an FMS. If a logical "1" is received from the AI, then the FMS does not change at the output of the phase modulator, and when "0" is supplied, then the FMS is inverted in the current interval. In this way, the binary information symbols are transferred to the PNS. Further, in the modulator, balanced modulation of oscillations is carried out (signals come from a low-frequency generator). The modulator implements the required phase inversion of the carrier wave when varying the AI binary signals. The received signals are amplified in power by an amplifier and radiated through the antenna into space (transmitted over a communication channel). Further operation of the system is described in the method.

The disadvantages of the method and system of the prototype is the need to search for and synchronize signals in the transmitter and receiver. This reduces the performance of the system as a whole. Before transmitting message signals, it is required to spend time on preparation, and the higher the energy secrecy of the system, the lower the signal power at the input, the longer the detection time is required to search and synchronize signals [6, p. 9]. In addition, when synchronizing, it is necessary to use a search and acquisition system, which reduces energy efficiency due to the complexity of the design of the prototype system [6, p. 16, 17]. At the same time, the frequency band within which the system operates is not effectively used.

In systems for transmitting discrete messages, the elements of messages are logical "1" and "0", and in computing systems, data is represented in the form of bytes, for which pulses of different polarity "±1" are used.

Brief summary of the essence of the method and composition of the system of the invention

Let the system input, for example, have elements of discrete messages in the form of logical "1" or "0". There are g=2 different NPSs (denoted S ₁ , S ₂ ) for each of which the level of side peaks (SBP) of the autocorrelation function (ACF) is not more than a positive number R, and the values of the SBP of the cross-correlation function (CCF) of these NPSs are not more than a positive number W. Each "1" pulse is assigned S ₁ , and any "0" pulse is assigned S ₂ . These NSSs are energetically secretive, optimally transmitted to the receiver. With the help of two SFs, the signals transmitted over the communication channel are different [6, p. 158, 159] due to the restrictions imposed on the UBP of ACF and VKF. At the outputs of different SF and threshold devices, pulses are generated, indicating that the receiver has received S ₁ or S ₂ . These pulses trigger either the "1" shaper or the "0" shaper, respectively, and the signals transmitted to the receiver are reproduced at the receiver output.

This approach is also applicable for the case when the input discrete message is divided into groups, blocks, for example, eight pulses each (standard bytes). Each block in the form of a byte corresponds to one of the numbers 0, ..., 255 (in total g ₁ =256 numerical values for all elements of the coding system). It is required to use g=256 NPS (denoted as S ₁ , S ₂ ,…,S _g ) with the specified restrictions on UBP, which are one-to-one mapped to blocks in the form of bytes with the same numerical values. These NSSs are energetically secretive, in an optimal way, including in the presence of noise, are transmitted to the receiving part. With the help of a set of SFs, they are detected against the background of noise and differ due to restrictions on the UBP of the ACF and VKF. Depending on the output of which SF a signal is detected that has exceeded the threshold level, taking into account the mutual uniqueness, the corresponding byte is restored, which is transmitted to the PI.

Thus, covert transmission with increased speed is provided due to the absence of the need for synchronization of signals, the design is simplified due to the absence of a signal search system. In addition, NPS, which are associated with blocks (bytes), have a longer duration than KB in the prototype, therefore, in the claimed method and system, the signals occupy a smaller frequency band, that is, the frequency band within which the system operates is used more efficiently. Covert transmission with increased speed is provided due to the absence of the need for signal synchronization, the design is simplified due to the absence of a signal search system, and energy efficiency is increased.

Initially, it is required to select symbols and determine their number g ₁ in the coding system. In the general case, in the claimed method, the elements of discrete messages can be grouped not only one by one or eight, but also by an arbitrary number of pulses g ₂ , and g ₂ =log ₂ g ₁ (rounding up to the nearest integer), where g ₁ - the number of symbols in the coding system, g ₂ - the number of elements (pulses, bits) of discrete messages in blocks.

Secrecy of signal transmission means [6, p. 8, 9] that it is required to use special methods and devices to detect the fact of signal transmission in the presence of noise, and it is also necessary to measure the main signal parameters. The optimality of signal processing in the presence of noise remains valid even in the presence of a wide range of interference (narrow-band, impulse, structural) [6, p. 7].

For example, R-codes [7, 8] and signals based on them, which are a kind of PMS, can be used as NLS.

Some information about R-codes and ensembles. In control, communication and radar systems, NLSs [6] are widely used, which have certain advantages. A variety of SPS are FMS. They consist of a sequence of N radio pulses with the same frequency and amplitude (we assume it is equal to one). The sequence of radio pulses with different initial phases is characterized by a binary code sequence or simply code G. At the same time, the FMS based on these codes [7], in which the autocorrelation function (ACF) in the region of side peaks varies within ±R (1≤R≤N- 1, R - integer) are called signals of the R-th kind (FMS-R). At the same time, the set of g codes G=G ^x _R,N , (x=1,…,g) corresponding to such signals is called R-codes (these are binary codes, in which the ACF in the region of side peaks varies within ±R , that is, R is the largest allowable value of the side peaks of the ACF module).

For a few KB R=1. The largest value (peak) of the ACF modulus of such N-element codes is denoted by u _m and u _m =N, and the relative level of side peaks (UBP) of the ACF is equal to B ₁ =R/N. The PMS base is equal to B=N, the signal energy E _c is directly proportional to N, that is, _{um is} proportional to E _c . A sign of a broadband signal is the correctness of the condition that the base is large (B>>1) [6]. Pairs of codes are characterized by the largest value of the module of the cross-correlation function (CCF), denoted by W(1≤W≤N-1, W is an integer). True: R<u _m , W<u _m .

FMS-R based on binary R-codes are pulse signals. For optimal detection and discrimination between these codes and signals in the presence of noise, known methods and schemes (matched filters and correlators) are used [6].

Some NPS collections have certain properties that allow them to be considered together as ensembles for constructing alphabets. In works [9-11] questions of finding R-codes are considered.

The symbol T denotes the duration of each of the N radio pulses of the FMS-R. The initial phases can be equal to 0 or π (180°), and codes are usually represented by a sequence of coefficients, respectively (+1, -1), for example, (1, -1, -1, -1, -1,1) for N= 6; R=2. In the general case, the initial phases of the radio pulses can be equal to ϕ ₀ +0 when the code factor is (+1), or ϕ ₀ +π, in the case when the code factor is (-1), where ϕ ₀ is a fixed component of the specified initial phase (the main thing is that the phase difference is 0 or π).

Further, signals based on binary codes are considered to be such NSSs that consist of radio pulses with initial phases equal to (ϕ ₀ +0) or (ϕ ₀ + π), and no restrictions are imposed on changes in the amplitudes and frequencies of radio pulses, but restrictions are introduced on the UBP ACF and VKF.

A set of binary pulse codes is presented, in which the UBP ACF and VKF satisfy certain requirements, in the form

where G ^x _{R, N} - binary code;

P ^x _j , j=1,…, N - coefficients of the x-th code of the ensemble;

x - code numbering index, x=1,…, g;

g is the number of codes in the set or signals based on them;

R - the largest allowable value of the side peaks of the ACF module, 1≤R≤N-1, R - integer;

N is the number of coefficients in codes and signals based on them.

Ensemble is a set of codes with introduced restrictions on UBP ACF and VKF. For example, for codes with P ^x _j =±1*, R=3, N=30, W≤29, g=256: G ¹ _3.30 =(1,1,-1,-1,-1,1 …1), G ² _3.30 =(1,-1,-1,-1,-1,1…1),…, G ²⁵⁶ _3.30 =(1,-1,-1,-1, 1…1).

Constraints on the UBP of ACF and VKF are formulated analytically [7, 8]. At the moments t _k =k⋅T, where k=1,…, N-1, counted from the beginning of the ACF (k=0), the values of the ACF modulus take extreme or zero values and at k=N are equal to N.

The values of the modulus of the VKF of pairs of ensemble codes with indices "x" and "y" are considered at the moments t _k =k⋅T counted from the beginning of the VKF. Ensemble codes with restrictions on UBP ACF and VKF according to [7-11] can be represented as inequalities with respect to code coefficients:

where P ⁱ _j , P ⁱ _N+jk , j=1,…, N - coefficients of the i-th code of the ensemble;

N is the number of coefficients in the codes of the ensemble or in signals based on them;

k - numbering index of time points of the autocorrelation function;

R - allowable UBP ACF, set by the user, 1≤R≤N-1, R - integer;

g is the number of codes or signals based on them in the ensemble;

where P ^x _j , P ^y _N+jk , j=1,…,N - coefficients of the x-th y-th codes of the ensemble;

x, y(x≠y) - indices of different codes in the ensemble, taking values from 1 to g;

g is the number of codes in the ensemble or signals based on them;

N is the number of coefficients in the codes of the ensemble or in signals based on them;

k - numbering index of time points of the cross-correlation function;

W - allowable level of side peaks of the cross-correlation function, set by the user, 1≤W≤N-1, W - integer;

g=g ₁ - the number of characters in the coding system.

Ensemble codes (1)-(3) are a special case of NPS S ₁ , S ₂ , ..., S _g and are generated by the NPS generator. The parameters N, R, W and g are interdependent.

When transmitting discrete messages in computer science and computer technology, each byte corresponds to a specific character of the coding system. If each character and byte, respectively, is assigned a code from the ensemble, then an alphabet will be obtained. When using the well-known ASCII coding system (American Standard Code for Information Interchange) [12], consisting of g ₁ =256 characters, an ensemble of codes of the same number g=g ₁ [9-11] is required. Characters correspond to numerical values ranging from 0 to 255, which, as you know, are represented by a set of eight bits that make up a byte. In general, for a coding system of g ₁ symbols, it is required to use g ₂ =log ₂ g ₁ elements (bits, pulses) in each block. For a two-character (g ₁ =2) coding system, a block consists of a single element (g ₂ =1) that takes two values, an ensemble of two codes is required. In addition to symbols, the coding system can determine the correspondence between the levels of an arbitrary signal at certain points in time and their code values in the form of bytes or blocks.

The user (recipient) can create a coding system at his own discretion, including as elements not only various characters, but also their combinations, for example, syllables, words, sentences, media files.

Some terms used to simplify the description

Alphabet - a one-to-one correspondence between the elements of the coding system and the codes or signals that make up the ensemble.

Ensemble - a set of binary codes or pulse signals based on them, for which restrictions are introduced on UBP ACF (R) and VKF (W).

Signals based on binary codes are impulse signals consisting of radio pulses, the initial phases of which are equal to (ϕ ₀ +0) or (ϕ ₀ + π), where ϕ ₀ is a fixed component of the specified initial phase, and the requirements for changes in the amplitude and frequency of the radio pulses are not imposed, restrictions (2), (3) are introduced for them on the UBP of the ACF and VKF. If the amplitudes and frequencies are constant, then there are FMS-R ensembles.

Block - a set of a finite number of elements of a discrete message, for example, a block of eight bits is a byte.

Form - a set of codes for which a one-to-one correspondence of integers in order from 1 to g and codes of the ensemble (1) is specified, for example, (G ¹ _3.30 ; ...; G ²⁵⁶ _3.30 ) with g=256.

The elements of discrete messages that make up blocks can be logical ones and zeros, or positive and negative logical ones. The numerical values of the blocks are determined by the sequence of elements that are considered as digits of the binary system, and if positive and negative logical ones are selected as elements, then when calculating the numerical values of the block, negative logical ones are replaced by zeros.

The essence of the invention

The task to be solved by the claimed invention of the method and system for its implementation is to ensure the security of discrete messages from external influences during their transmission over a communication channel.

принятого ШПС, формирование на основе наличия сигнала распознавания ШПС каждого восстановленного выходного блока с соответствующим числовым значением А, совпадающего с переданным блоком входного дискретного сообщения, передача восстановленных дискретных сообщений на выход получателю.The problem is solved due to the fact that in the method of transmitting discrete messages, which consist of elements in the form of logical ones and zeros, or of positive and negative logical ones, including on the transmitting side the conversion of one type of discrete message into a broadband signal and the conversion of elements of a different type of this discrete message into another broadband signal, the transmission of this sequence of broadband signals over a communication channel, the implementation of a typical transceiver of broadband signals, followed by the operation of their matched filtering on the receiving side, the comparison of the received signal with a threshold level, as new features are introduced such operations as choosing g ₁ different elements for the coding system of discrete messages, the numbering of these elements from zero to (g ₁ -1), the grouping of consecutive elements of the input discrete message into blocks of duration T _b by g ₂ elements, where g ₂ =log ₂ g ₁ rounded to larger side to the nearest integer or setting parameter g ₂ equal to the number of elements in the block of the input encrypted discrete message or message with redundant coding, while g ₁ =2 ^a , where a=g ₂ , the choice of g=g ₁ different noise-like signals , the level of the side peaks of the autocorrelation and cross-correlation functions of which are not more than positive numbers R and W, respectively, where R and W are numbers less than the largest value u _m of the modulus of the autocorrelation functions of these noise-like signals, the numbering of the selected noise-like signals sequentially with integers from 1 to g and location in the form, establishing a one-to-one correspondence between the elements of the discrete message block, which corresponds to one of the integer numerical values A, where 0≤A≤(g ₁ -1), and noise-like signals having the serial number A+1 in the form, location of each of the selected noise-like signals within the interval T _b following the interval where the block is located, to which the corresponding noise-like signal is assigned, the creation for the grouped sequence of elements of the input discrete message of the corresponding sequence from the noise-like signals S _A+1 selected in the indicated way, the transmission of the sequence noise-like signals through the propagation medium of the communication channel directly or using as modulating signals, the implementation of matched filtering of the received sequence by all g ₁ different matched filters, each of which is matched with one of the noise-like signals included in the form, comparing each of the output signals of the matched filters with the corresponding threshold level U _p , which should be less than the largest values at the output of the matched filters, when there is a NPS at the filter input, with which this filter is matched, at the same time, the threshold levels U _p are selected greater than the largest of the numbers R and W, checking the excess of each of signals received after performing coordinated filtering of all received NPSs having the A + 1st serial number in the form, the values of the corresponding threshold level U _p and, in case of such an excess, the formation of recognition signals

of the received NPS, forming based on the presence of the NPS recognition signal of each restored output block with the corresponding numerical value A, coinciding with the transmitted block of the input discrete message, transmitting the recovered discrete messages to the output to the recipient.

The proposed method is illustrated by diagrams in Fig. 12.

первого ШПС из формуляра, который запускает формирователь байтов с А=0. Следовательно, блоки элементов входного дискретного сообщения однозначно восстанавливается на выходе. Отметим также, что подсчет числовых значений блоков, состоящих из элементов "±1", возможен, например, если логическую "-1" заменить на ноль.Explanation with an example. The input byte with A=0 is assigned to the first SPS from the form. After matched filtering, a recognition signal is formed

the first PSS from the form that starts the byte shaper with A=0. Consequently, blocks of elements of the input discrete message are uniquely restored at the output. We also note that the calculation of the numerical values of blocks consisting of elements "±1" is possible, for example, if the logical "-1" is replaced by zero.

The solution of the problem to which the invention is directed is realized due to the fact that the system for implementing the method of transmitting discrete messages contains a noise-like signal generator, a communication channel, a matched filter, a decision device, as new features, a converter of input discrete messages, a shaper of output discrete messages, moreover, the input of the input discrete message converter is connected to the input of the discrete message transmission system, the input discrete message converter contains g ₁ outputs, which are connected respectively to the same number of inputs of the noise-like signal generator, the output of this generator is connected to the input of the communication channel, the output of which is connected to the input of the matched a filter containing g ₁ outputs connected to the same number of inputs of the decision device, having g ₁ outputs connected to the same number of inputs of the generator of output discrete messages, the output of which is connected to the output of the entire system, while the noise-like signal generator is a functional group of g=g ₁ code generators of an ensemble of noise-like signals or signals based on them, in which the level of side peaks of the autocorrelation function of each signal does not exceed R<u _m - the largest value of the modulus of autocorrelation functions of these noise-like signals, the level of side peaks of the cross-correlation function of each noise-like signal with all other (g-1) generated signals does not exceed W<u _m , R and W are positive numbers, the inputs of the generators of codes of the ensemble of noise-like signals or signals based on them are the inputs of the functional group, the outputs of the generators of codes of the ensemble of noise-like signals or signals based on them are connected in parallel and constitute the output of the functional group, the matched filter is a functional group of g matched filters, the inputs of which are connected in parallel, the impulse responses of each of the matched filters are optimal for one of the different signals of the noise-like signal generator, the inputs and outputs of the matched filters are the inputs and outputs of the functional group , the decision device for analyzing the output signals of each matched filter is a functional group of g ₁ decision devices, the inputs and outputs of which are the inputs and outputs of the functional group, the input discrete message converter contains a converter logic device and a converter interface device, the input of the converter interface device is connected to the input of the discrete message transmission system, the output of the interface device is connected to the input of the logical device of the converter, the outputs of which are connected to the outputs of the converter of the input discrete messages, the generator of the output discrete messages contains the restorer of the elements of discrete messages and the interface device of the generator, the inputs of the restorer of the elements of discrete messages are connected to the inputs of the generator of the output discrete messages, the output of the restorer of elements of discrete messages is connected to the input of the interface device of the shaper, the output of which is connected to the output of the system for transmitting discrete messages.

The presented set of essential features allows you to obtain a technical result and achieve the goals of the invention, which are to increase the speed with a simultaneous increase in the energy secrecy of the discrete message transmission system, including in the presence of noise in an optimal way, and also consist in increasing the efficiency of using the frequency band and increasing energy efficiency by simplifying the design.

The proposed system is illustrated by a block diagram (Fig. 3).

List of figures of the graphic image

Fig. 1 - diagrams explaining the method of transmitting discrete messages in a particular case;

Fig. 2 - diagrams explaining the method of transmitting discrete messages in the general case;

Fig. 3 is a block diagram of a system for transmitting discrete messages;

Fig. 4 - table of transducer LF values.

Information confirming the possibility of carrying out the invention

1. Converter logic function

The operation of the discrete message transmission system, in particular, is based on the use of the logical function (LF) of the converter that controls the operation of the logic device of the converter. Relationships and a table of values used in describing the operation of the discrete message transmission system are obtained. The LF of the converter of input discrete messages is considered.

For definiteness, in a particular case, the option of grouping discrete messages by eight elements (byte-by-byte version) is chosen, which corresponds to the ASCII system (g ₁ =256). A LF is presented, which allows, when changing the numerical values of bytes from 0 to 255, to obtain the output values of the logical "1" only for a single set of these numerical values. For the LF of the converter in which this LF is used, this means that out of all g ₁ outputs, a single signal for each byte with a different numerical value is generated only at one of the outputs, and at all other outputs it is equal to zero. The signal received at one of the outputs starts the required shaper of the NPS generator.

Designations introduced:

input data in binary and decimal system (only the first two bytes are written);

output data in binary and decimal systems (the first two bytes and values are given). For the specificity of the presentation of this example of the record adopted g ₂ =8.

The method and system make it possible to transmit input signals (4) over a communication channel and obtain output signals (5), which requires the use of an LF, which is compiled on the basis of a truth table (Fig. 4) according to the rules [13, p. 31; 14, p. 18].

, n=1,…, g1, которые требуется использовать для получения импульсов запуска генератора ШПС. Каждому входному блоку (байту) соответствует число, которое обозначено

. Требуется получить импульс (соответствующие значения ЛФ отмечены на фиг. 4 как "1") только на

выходе из всех имеющихся g₁=256 выходов (значение и номер по порядку различаются на единицу), а на остальных выходах должно формироваться значение "0". Полученный сигнал позволяет далее с помощью генератора ШПС сформировать только

ШПС из всех возможных g₁=256 вариантов. То есть, если на входе имеется байт, например, соответствующий десятичному числу 184, то ЛФ позволит сформировать импульс "1" лишь на

выходе, что позволяет получить требуемый 185-й ШПС из формуляра.LF transducer consists of components

, n=1,…, g1, which are required to be used to obtain the start pulses of the NPS generator. Each input block (byte) corresponds to a number, which is indicated

. It is required to obtain an impulse (the corresponding LF values are marked in Fig. 4 as "1") only on

output from all available g ₁ =256 outputs (the value and order number differ by one), and the value "0" should be formed on the remaining outputs. The received signal allows further, using the NLS generator, to form only

NPS from all possible g ₁ =256 options. That is, if there is a byte at the input, for example, corresponding to the decimal number 184, then the LF will allow you to generate a pulse "1" only for

output, which allows you to get the required 185th SPS from the form.

- компоненты ЛФ от этих аргументов, причем, значение ЛФ равно "1" только для

набора аргументов

, а для остальных вариантов сигнал равен "0". Для простоты указано лишь несколько числовых значений. В первой колонке - номера по порядку, в колонках со второй по десятую - десятичные и двоичные числовые значения бит, соответствующие символам системы ASCII. В остальных колонках - требуемые значения ЛФ.In the table of Fig. 4 the notation is introduced: (X _{i, j} , i=1,…,8; j=1,2,…, 256) - arguments from (4);

- components of LF from these arguments, moreover, the value of LF is equal to "1" only for

set of arguments

, and for other options the signal is equal to "0". For simplicity, only a few numerical values are indicated. In the first column - numbers in order, in columns from the second to the tenth - decimal and binary numerical values of the bits corresponding to the characters of the ASCII system. In the remaining columns - the required values of LF.

лишь для n-го байта, n=1,…, g₁). Применяя известные правила [13, с. 31; 14, с. 18], получим компоненты ЛФ. Например:If there is a signal at the first output of the device that implements the LF, then at all other outputs the function and signal are equal to zero, if the signal is at the second output, then at all other outputs the signal is equal to zero, and so on (

only for the n-th byte, n=1,…, g ₁ ). Applying the known rules [13, p. 31; 14, p. 18], we obtain the LF components. For example:

where n=g ₁ =256, j=1, 2, ... - byte numbering index;

symbol (*) - inversion operation.

) в формулы (6), то получим соответственно в первом случае

(другие компоненты равны нулю), во втором варианте

(прочие компоненты нулевые), для третьего набора отлична от нуля лишь

. Эти величины определяют ЛФ управления формирователями ШПС.If we substitute the binary values of the numbers from columns 3...10 of Fig. 4 consecutively, for example, for j=1,185,256 (that is, when A and

) into formulas (6), then we obtain, respectively, in the first case

(other components are equal to zero), in the second variant

(other components are zero), for the third set, only

. These values determine the LF of the control of the SHPS shapers.

In the general case, as indicated in the method, any block of discrete messages contains g ₂ elements (pulses, bits). For their transmission, g=g ₁ NPS is required, the considered LFs will contain the same number of components.

2. An example of an SPS form

An example of a form is given. FMS in the form of R-codes and signals based on them, for example, G ^x _{R, N} (N=30; R=3; W=29; x=1,…, g; g=256) was chosen as NPS.

The highest value of the ACF of any signal is determined by its energy [6]. At the same time, the modules of the peak values of the VKF are always less than the highest value of the ACF. This allows, through the operation of consistent filtering of the selected (included in the form) set of any NPS differing in parameters [6], to detect and distinguish them.

With regard to the FMS, in particular, to R-codes and signals based on them, since R<N, W<N, various codes of the presented form form an ensemble with parameters N, R, W and conditions (2), (3) are satisfied . This allows, by analyzing the UBP of the ACF and the VKF, to distinguish codes and signals based on them from each other and to restore the discrete messages transmitted over the communication channel. It is expedient to use ensembles of codes and signals based on them with the lowest possible values of the ACF and CCF UBP [7, 8].

3. Description of the method and system for transmitting discrete messages

3.1. A method for transmitting discrete messages. The differences between the prototype and the claimed method are presented. In FIG. 1 (a) gives an example of signals of input discrete messages. In FIG. 1 (b) shows a drawing related to the prototype, in which for each element of input discrete messages at subsequent time intervals, a KB is formed if the discrete message element is equal to "1" or an inverted KB is created when the input is "0".

In the drawings of FIG. 1 shows the case T=T _b when the pulses of discrete messages have a duration T and are grouped one by one. Here, the block consists of a single element (pulse) of the input signals, therefore, the duration of the block is equal to the duration of this pulse (Fig. 1 (a)), g ₁ =2, g ₂ =1. The numerical values of the blocks are A=0 or 1. In FIG. 1(c) depicts a variant related to the claimed system. For concreteness, logical "1" and "0" are chosen as elements. Two different NPSs S ₁ , S ₂ are used, occupying a part of the interval of duration T on which they are generated. Signals can be, in particular, any two FMS in the form of R-codes and signals based on them, presented earlier in the form. The choice of NPS takes place taking into account the fulfillment of the restrictions on the UBP of the ACF and VKF. In accordance with the description of the method, if the discrete message element is equal to "1" (Fig. 1 (a)), then it is one-to-one associated with S ₁ , and if the input is "0", then S ₂ is formed. As a result, there is a sequence of NPS, each of which is located within the intervals T=T _b following the elements of discrete messages, which were assigned to these NPS. This sequence after the transmission of the COP is subjected to the operation of the matched filtering of the signals S ₁ and S ₂ . In FIG. 1(d) outlines the main peaks of the autocorrelation functions (the structure of the side peaks is not shown), obtained by performing operations of matched filtering S ₁ with respect to S ₁ and matched filtering S ₂ with respect to S ₂ . The values of the main peaks are designated U _m1 and U _m2 respectively. At the same time, when carrying out operations of matched filtering S ₁ with respect to S ₂ and matched filtering S ₂ with respect to S ₁ , CCFs are formed, the peak values of which are less than U _m1 and U _m1 .

The operations of comparing with a threshold value and checking if these values are exceeded are illustrated using the diagrams in FIG. 1 (d). It conditionally shows the correspondence of the levels of the parameters R, W, U _p . Threshold values are selected in accordance with the claimed method (max(R, W)≤U _p ≤min(U _m1 ,U _m2 )).

,

распознавания соответственно S₁ или S₂. По сигналам распознавания запускается формирователь элементов "1" или "0" и генерируются выходное дискретное сообщение, идентичное входному (фиг. 1 (а)).The signals received after the matched filtering operation S ₁ or S ₂ with respect to S ₁ or S ₂ are compared with threshold values. The absence or presence of the values of these level signals exceeding the threshold values is recorded, in case of exceeding, a signal is generated

,

recognition respectively S ₁ or S ₂ . According to the recognition signals, the shaper of the elements "1" or "0" is launched and an output discrete message is generated that is identical to the input one (Fig. 1 (a)).

In FIG. Figure 2 shows drawings illustrating the claimed method in the general case. The elements of the input discrete message grouped by g ₂ constitute blocks of duration T _b =g ₂ ⋅T, g ₂ =1, 2, ..., 8, ..., they are shown in Fig. 2(a). The values \u200b\u200bof each element are indicated, starting with the least significant digits, so that the byte corresponds to the number A. Within the next interval of duration T _b , a signal S _A+1 is formed, the serial number of which determines the type of code or signal based on it from SPS form. For example, if the ellipsis is ignored, then for the sequence shown in FIG. 2 (a) and written in the generally accepted form from the highest digits, we have 01001110 ₂ , A=78, it is required to use the code from the form under the number 79.

The method and system can also be used in the case when the input code is over-encoded discrete messages or pre-encrypted discrete messages, for example, by block symmetric or asymmetric encryption, or encrypted in any other way. Then it is considered that the grouping of elements of discrete messages into blocks has already been carried out and g ₂ is chosen equal to the number of elements in the input blocks, therefore, g ₁ =2 ^a , where a=g ₂ .

Next, the operations described in the description of a particular case of the implementation of the claimed method, when g ₁ =2, g ₂ =1, are carried out: transmission over a communication channel, comparing the signals received after matched filtering with threshold values, checking if these threshold values are exceeded, generating a recognition signal , according to which, in accordance with the mutual uniqueness of blocks and NPS, an identical input block of discrete messages is formed, directed to the output to the recipient.

3.2. Discrete messaging system. This system is shown in Fig. 3 and contains a converter of input discrete messages 1, a generator of noise-like signals 2, a communication channel 3, a matched filter 4, a solver 5, a generator of output discrete messages 6, while the input of the converter of input discrete messages 1 is connected to the input of the entire system, a group g of outputs of the specified converter is connected to a group g of inputs of the noise-like signal generator 2, the output of this generator is connected to the input of the communication channel 3, the output of the communication channel 3 is connected to the input of the matched filter 4, the g outputs of which are connected to the g inputs of the decision device 5, which has g outputs that are connected to the same number of inputs of the generator of output discrete messages 6, the output of which is connected to the output of the system, at the same time, the generator of noise-like signals 2 is a functional group of g=g ₁ generators of codes of an ensemble of various noise-like signals or signals based on them, these signals satisfy the relations ( 2), restrictions (3) and their level of side peaks of the autocorrelation function is not more than a positive number R<um - the largest value of the modulus of autocorrelation functions of these noise-like signals, the level of side peaks of the cross-correlation function of each noise-like signal with all other (g-1) generated noise-like signals also does not exceed a positive number W<u _m , g inputs of the code generators of the ensemble of noise-like signals or signals based on them are the inputs of this functional group, the outputs of the generators of codes of the ensemble of various noise-like signals or signals based on them are connected in parallel and constitute the output of the functional group, the matched filter 4 is a functional group of g matched filters, the inputs of which are connected in parallel, the impulse responses of each of the matched filters are optimal for one of the different signals of the noise-like signal generator 2, the inputs and outputs of the matched filters are the inputs and outputs of this functional group, the solver 5 for analysis of the output signals of each matched filter is a functional group of g ₁ decision devices, the inputs and outputs of which are the inputs and outputs of this functional group; converter of input discrete messages 1 contains a logic device of the converter 7 and an interface device of the converter 8, the input of the logic device of the converter 7 is connected to the output of the interface device of the converter 8, g outputs of the logic device of the converter 7 are connected to the outputs of the converter of the input discrete messages 1, the input of the interface device of the converter 8 is connected to the input of the converter of input discrete messages 1; the generator of output discrete messages 6 contains a restorer of elements of discrete messages 9 and a coupling device of the shaper 10, g inputs of the restorer of elements of discrete messages 9 are connected to the inputs of the generator of output discrete messages 6, the output of the restorer of elements of discrete messages 9 is connected to the input of the converter of the elements of discrete messages 10, the output of which is connected with the output of the shaper of output discrete messages 6.

4. Composition and operation of individual devices of the system

Devices 1, 2, 7, 8 from the diagram in Fig. 3 constitute the transmitting part, and the devices 4, 5, 9, 10 are included in the restoring part, as a result, both parts are connected by means of the COP 3 into a system for transmitting discrete messages.

4.1. Converter of input discrete messages. Let the coding system be chosen initially and its elements and their number g ₁ be known. Converter input discrete messages (PDMS) 1 is designed to perform the operations specified in the claimed method of transmitting discrete messages, namely: grouping consecutive elements of the input discrete messages into blocks of g ₂ elements (pulses, bits), where g ₂ =log ₂ g ₁ (rounding up to the nearest whole number); the formation of trigger pulses for the generator SPS 2, as well as for matching the LU of the converter 7 with the transmission line, through which the elements of these messages arrive at the input of the discrete message transmission system (for example, resistance matching and discrete message presentation forms).

PVDS 1 consists of a logical device of the converter 7 and an interface device of the converter 8. The LU of the converter 7 implements the LF of controlling the shapers of the SHPS according to relation (6).

The interface device of the converter 8 is designed to perform several functions. First of all, this is the control of grouping successively the following elements of a discrete message into blocks of g ₂ elements. For this, in particular, a clock generator of pulses can be used, following with a period of duration T _b . It can be performed on the elements of analog or discrete circuitry [13-15], be part of the interface device of the converter 8. The pulses of discrete messages through the interface device of the converter 8 enter the input register LU of the converter 7, fill all its g ₂ cells. According to the pulses of the clock generator, which fixes the end of the time interval for filling all the cells of the input register, the sizes of the blocks are set. Also, in the logical device of the converter 7 (in accordance with the LF of the converter of type (6)) the operations of converting the signals of the input block (byte) from the register into the start pulse of the generator SHPS 2 are performed. The start and end of the blocks, the number of elements in any block, as well as further steps for transforming blocks.

The interface device of the converter 8 is also designed to match the LU of the converter 7 with the communication line, through which input signals of discrete messages are supplied to the system input from the source, or to agree on the form of presentation of the input messages, or to apply known rules that need to be implemented for the operability of the LU of the converter 7 Message form negotiation may consist, for example, in the conversion of serial transmission of blocks in the form of bytes into parallel byte sequence or in the use of some protocols, data transmission/reception standards. Elements of analog and discrete circuitry are used. Matching the resistance with the help of the interface device of the Converter 8 allows energy efficient and without distortion to transfer to the PVDS 1 the signals of the input messages. In uncoordinated communication lines, data distortions are possible [15, p. 29-32]. They can be reduced by using a matching device [15, p. 32-40] or data input/output standards [15, p. 43-53], which also refers to the function of the interface device. The interface device of the converter 8 can be made on passive or active elements [14, 15] (transistors, microcircuits), in the form of a USB universal serial bus. All options provide the same technical result.

LU converter 7 implements LF type (6). The purpose of the converter is that the combination of input signals (elements of blocks, bits of the input byte) is converted into another set of signals required to carry out the operations of forming the NPS.

(6). Результаты перемножения подаются на g₁ выходов ЛУ преобразователя 7 и обеспечивают достижение результата воздействия ЛФ на входные сигналы.To specify the presentation, as well as in the formulas (6) of the considered example, selected g ₁ =256 (g ₂ =8). The LF components are the product of the arguments that enter it with or without inversion. At the input of the LU of the converter 7 there is a register of g ₁ cells connected to the branches, which consist of multipliers that form the product of g ₂ signals from the cells of the register included in it with or without inversion (depending on the type of LF type (6)). The connection of the inverters to the multipliers is done at the factory and is permanent, no control signals are required. The inverter can be built on "NOT" elements. As a result, each branch of the circuits makes it possible to obtain one of the LF components

(6). The multiplication results are fed to g ₁ outputs of the LU converter 7 and ensure the achievement of the result of the impact of the LF on the input signals.

LU converter 7 can be built, for example, on the logic elements "AND", "OR", "NOT" [13, 14], and can also be made in the form of a programmable logic array (FPGA) [14, 15 p. 494, 534] or its variety, or a new type of FPGA that may be created in the future. All variants provide the same technical result.

The work of PVDS 1 on the example of the case when g ₂ =8 and blocks are bytes. The input elements of discrete messages in the form of bytes are fed to the input of the interface device of the converter 8, which ensures efficient signal transmission to the LU of the converter 7, which converts the bytes in accordance with the LF of the converter. This makes it possible to obtain a trigger signal on one of the g ₁ outputs (Fig. 3), which is further transmitted to the PSS generator 2. Later, one of the PSS of the form is formed from this signal, the number of which one-to-one corresponds to rows 3-10 of the table of FIG. 4 (the numerical values of the bytes are given in binary form): j=A+1 is the sequence number, A is the decimal value of the number corresponding to the row in the table of FIG. 4, x=A+1 - numbering index of the ensemble code in the form. As a result, the numerical value A, which corresponds to the current byte, allows you to generate the required NPN S _A+1 according to the method of transmitting discrete messages.

4.2. ShPS generator. In accordance with the method of transmitting discrete messages, this device 2 (Fig. 3) is designed to form the NPS. For the purposes of concretization, FMS was chosen in the form of R-codes. The codes of the ensemble and the signals based on them satisfy the requirements (1) - (3) and correspond to the serial numbers x=A+1 of the form, where A are the numerical values that correspond to the bytes of the input discrete messages.

The NPS generator 2 is a functional group consisting of g generators of ensemble codes that can be built on microcircuits [6, fig. 3.11, p. 47 example for KB] or in the form of devices on surface acoustic waves (SAW) [6, p. 357]. The sequence of symbols in the codes determines the geometric arrangement of the SAW transducer electrodes in these devices.

For the ensemble code generators, the NPS generator 2 has g=g ₁ individual inputs (FIG. 3). One of the various codes of the ensemble is formed. All outputs of the shapers are connected to the g-input adder, the output of which is the only output of the NPS 2 generator.

In the operating mode, at one of the individual inputs of the shapers of the SPS generator 2, there is a trigger pulse from the converter of input discrete messages 1, and there is no such pulse at all other inputs. Therefore, one of the shapers responds with the corresponding code (1) - (3), appearing at the output of the adder and the entire NPS generator 2. As a result, each byte is put into a one-to-one correspondence with the required ensemble code or signal based on this code presented in the form. Codes are transmitted via CS 3 for further conversion and data recovery operation.

It is possible to generate ensemble codes in a form suitable for transmitting a sequence of broadband signals over a communication channel directly or as modulating signals of carrier oscillations, then the SPS generator 2 implements an additional modulation function. SAW devices allow you to immediately receive signals based on the selected ensemble codes for transmission over COP 3 at a carrier frequency in a fairly wide frequency range.

The SPS generator 2 can be made in the form of a storage device in which all the required signals are recorded and from which can be retrieved. These signals are the output for the specified generator. The NPS generator 2 can be made in the form of an FPGA [14, 15, p. 494, 534] or its variety or a new version of the FPGA, which may be created in the future. Then the output signal is determined by the corresponding logical function that sets the control signals for the operation of the FPGA.

4.3. Link. To carry out the transmission of NPS (R-codes of the ensemble or signals based on them) to the restoring part of the proposed device, CS 3 is used. According to [16, p. 189] a communication channel (an analogous term is a communication line) is a set of technical means and a physical environment that ensures the propagation of message signals. The technical means may include a modulator (eg, a mixer with an amplifier), a transmitter (eg, amplifiers and antennas), a receiver (eg, a frequency converter with an amplifier), a demodulator. Physical media: solid, liquid, gaseous, vacuum. Channels are distinguished in the form of an electrical communication line (wired and radio communication), sound (acoustic) and light (optical) communication.

Discrete messages can be transmitted using electromagnetic waves propagating through wires, cables, waveguides, light guides, as well as in air and airless space. In particular, through a twisted pair, fiber optic cable (FOC), coaxial cable, radio channel of terrestrial or satellite communications [17].

An example of a solid physical medium is sound conductors of surface and bulk acoustic waves made of, for example, piezoquartz and lithium niobate. The length of sound wires is small, but they are practically insensitive to external influences, excluding direct physical destruction. Devices based on bulk and surface acoustic waves for sound (acoustic) CS 3 are presented in [18].

Sound (acoustic) communication lines in a liquid medium are considered in [19], where the features of acoustic underwater communication are indicated. CS 3 as light optical communication lines are presented in [20].

Auxiliary equipment (converters, amplifiers, antennas) are not considered here. All variants of COP 3 provide the same technical result.

4.4. matched filter. To detect and distinguish between NPSs received by CS 3 against the background of noise, SF 4 is used (Fig. 3), which is a functional group consisting of g optimal matched filters [6, p. 26] for each code or signal generated by the NPS 2 generator and entered into the form. A possible variant of the circuit SF 4 may consist of branches with inputs connected in parallel. Any branch includes SF for one of the ensemble codes (х=1,…, g, for example g=256) from the form. The SFs in the branches are numbered in the same way as the codes themselves. A functional group has one input and g outputs.

Filters can be implemented on microcircuits [6, p. 48, fig. 3.13, p. 366, fig. 22.5] or on SAW devices [6, p. 357, fig. 21], [16, 18]. The structure of the interdigital SAW SF converters is associated with the alternation "±1" in codes (1)-(3).

The input of the functional group of filters is connected to the CS 3 (Fig. 3), and its outputs are connected to the g inputs of the decision device 5. In the operating mode, the input signal received from the CS 3 is applied to all parallel branches. At the output of the SF of the corresponding branch, an ACF signal will be generated the code that was used to transmit the corresponding byte. ACF consists of two areas of side peaks, between which there is a main peak with a high signal level. All other SF outputs have a VKF signal, which can have several peaks, but the largest of them is always below the main peak of the ACF. It is necessary to use ensembles of codes with a low level of VCF peaks, which improves the quality of distinguishing one code from another, that is, different symbols of the coding system. The signals from the output of the block are further analyzed in the solver 5.

, в случае g=g₁=256. Для каждого байта дискретных сообщений один из сигналов распознавания равен, например, "1", а все другие равны "0".4.5. Solver. The output signals of the filter bank are compared with the threshold level in the solver 5, which has g inputs and the same number of outputs. The decision device 5 for analyzing the output signals of each matched filter is a functional group consisting of g decision devices. The inputs and outputs of the decision device 5 are connected to the inputs and outputs of the functional group. The signal of each filter of the functional group SF 4 is fed to the input of the corresponding branch of the solver 5. Next, a signal is generated in the case when the signal at the input of the branch of the solver 5 exceeds the set threshold value U _p , which means that the input of the block SF 4 code with a certain number according to form, agreed with the SF of this branch. These code recognition signals are labeled

, in case g=g ₁ =256. For each byte of discrete messages, one of the recognition signals is equal to, for example, "1", and all others are equal to "0".

A differential stage circuit or a digital comparator can be used as a threshold comparison device [14]. The threshold should be set above the level R of the side peaks of the ACF and the highest value W of all VCF codes, but below the level of the main peak of the ACF of all codes in the ensemble. Thus, a response is provided only to the peaks of the ACF, without a response to the signals of the VKF. As a result, in the operating mode, the form codes are distinguished and then the received signals are transmitted to the shaper of output discrete messages (FVDS) 6.

конкретного кода ШПС и соответственно байта (благодаря их взаимной однозначности). Сигнал распознавания подается на соответствующий выход и передается далее (фиг. 3) для восстановления байта (в общем случае блока) выходного дискретного сообщения.The operation of the decision device 5 is that when one of its inputs receives a signal from the SF 4, the threshold device is triggered and one of the detection and recognition signals is formed

a specific NPS code and, accordingly, a byte (due to their mutual unambiguity). The recognition signal is applied to the corresponding output and transmitted further (Fig. 3) to restore a byte (generally a block) of the output discrete message.

, в результате формируются восстановленные байты

, j=1, 2,состоящие из элементов в виде бит

любого j-го байта. При корректной работе они являются выходными байтами (5) системы и аналогичны входным дискретным сообщениям (4).4.6. Shaper of output discrete messages. The purpose of this device 6 is to generate output discrete messages of the claimed system on the basis of a one-to-one correspondence of blocks (in the particular case of bytes) and NPS (in this particular case, ensemble codes and signals based on them). Let blocks correspond to bytes. From the output of the deciding device 5 to the FVDS 6, code recognition signals are received

, as a result, recovered bytes are formed

, j=1, 2, consisting of elements in the form of bits

any j-th byte. When working correctly, they are the output bytes (5) of the system and are similar to the input discrete messages (4).

FVDS 6 consists of a restorer of elements of discrete messages 9 and an interface device of the shaper 10.

.The scheme of a possible variant of the restorer of elements of discrete messages 9 may include parallel branches, each of which consists of a byte shaper of the selected coding system. For example, the first branch consists of the shaper of the first byte with a numerical value of zero, the second branch of the second byte with a numerical value of one, and so on until the last 256th branch to form the 256th byte, corresponding to the number 255. The numerical values of the bytes of the coding system chosen for the example are presented in columns 3…10 in Fig. 4 in binary. Each branch is activated by the recognition signal corresponding to this branch

.

Restorer elements of discrete messages 9 consists of g ₁ generators of various blocks (bytes) with separate branch outputs. Any of these generators is connected to the corresponding input of the PVDS 6. Each generator is a generator of one of the various blocks (bytes), which consist of elements (logical "1", "0" or "±1") and form a set of pulses of the restored block. The shapers of various blocks can be made on the elements of discrete circuitry, for example, on shift registers with taps [6, p. 47.48]. Inverters are connected to the corresponding taps, which makes it possible to obtain the required combination of pulses, bits, on the adder of signals from all taps.

.The restorer of elements of discrete messages 9 can be made in the form of a permanent memory containing the values of all blocks, each of which is retrieved in the presence of code recognition signals

.

, который запускает формирователь импульсов этой ветви. В результате формируется набор элементов (бит), соответствующих h-му блоку восстановленных сообщений. Благодаря взаимно-однозначному соответствию вида входных блоков и кодов из формуляра, восстановленные блоки следуют в том же порядке, в каком они были в входном дискретном сообщении. Восстановленные блоки (байты

) являются выходными для всей системы, соответствуют входным элементам сообщений (1), (2) и далее передаются на вход сопрягающего устройство формирователя 10.In operating mode, from the decision device 5 to one of the inputs of the restorer of elements of discrete messages 9, for example, the h-th, a code recognition signal is received

, which starts the pulse shaper of this branch. As a result, a set of elements (bits) corresponding to the h-th block of recovered messages is formed. Due to the one-to-one correspondence between the type of input blocks and codes from the form, the restored blocks follow in the same order as they were in the input discrete message. Recovered blocks (bytes

) are output for the entire system, correspond to the input elements of messages (1), (2) and are then transferred to the input of the shaper 10 that interfaces the device.

The restorer of the elements of discrete messages 9 can be made in the form of a storage device, in which all the required signals are recorded and from which can be retrieved. These signals are the output for the specified generator. The restorer of elements of discrete messages 9 can be made in the form of an FPGA [14, 15, p. 494, 534] or its variations, or a new version of the FPGA, which may be created in the future. The control signals applied to the FPGA make it possible to implement the required block sequences. All embodiments provide the same technical result.

The conjugating device of the shaper 10 is designed to match the restorer of discrete message elements 9 with the transmission line, through which discrete messages are further transmitted to the recipient or to agree on the form of presentation of message elements. Coordination allows energy efficient and without distortion to transmit a message to its recipient. The harmonization of the form of the message representation may consist, for example, in the conversion of serial transmission of bytes to parallel transmission of bytes or in the use of known protocols or standards for data transmission/reception.

In uncoordinated communication lines, data distortions are possible [15, p. 29-32]. They can be reduced by using matching devices [15, p. 32-40] or data input/output standards [15, p. 43-53], which is also provided by the interfacing device 10. It can be made on passive or active elements (transistors, microcircuits) or in the form of a USB universal serial bus. For any variant, the same technical result is provided.

формируется h-й блок (байт) восстановленного после передачи по КС 3 дискретного сообщения. Восстановленные сообщения посредством сопрягающего устройства формирователя 10 энергетически эффективно, без искажений и в соответствующем виде (по протоколам и стандартам передачи/приема сообщений) передаются на выход системы. The operation of the FVDS 6. After the identification of the h-th code from the form and the arrival of the h-th input of the restorer of elements of discrete messages 9 of the recognition signal

the h-th block (byte) of the discrete message recovered after transmission via CS 3 is formed. The recovered messages are transmitted to the output of the system by means of the interface device of the shaper 10, energy-efficiently, without distortion and in the appropriate form (according to the protocols and standards for transmitting/receiving messages).

5. Operation of the claimed system based on the claimed method

On the example of symbols, the operations of the method and the operation of the system for transmitting input discrete messages (4) are considered. Let it be required to transmit the word NO in the ASCII system. We use [12], where the numerical value of a byte (in this description, this is parameter A) is called a code, we find for N and O the corresponding numbers 78 and 79. Codes from the form are respectively selected with numbers x=A+1, that is, x=79 , 80.

The input bytes of the discrete message NO from the source in an energetically optimal way pass the interface device of the converter 8 and are fed to the LU of the converter 7, where for the character byte N only on the 79th, and for the character byte O only on the 80th outputs, trigger signals are formed, which are a consequence of response of the LF component used in the LU of the converter 7 to the input signals.

The trigger signals are fed to the 79th and 80th inputs of the NPS generator 2. This leads to the formation of the corresponding codes or signals S _A+1 based on them. When using in the example R-codes or signals based on them (1)-(3) as NPS, codes from the previously given form with numbers 79 and 80, respectively, will be generated. If you do not take into account the ellipsis in FIG. 1 (a), then the byte presented there for example corresponds to the number A = 78, and for transmission over COP 3, the code from the above form is used at number 79. The generated signals arrive at COP 3 and are transmitted to the inputs of SF 4, consisting of a filter block for all signals from the form. As a result, only at the 79th output of SF 4 will the ACF of this NPS associated with the transmission of the N symbol be formed, and only at the 80th output for the transmitted symbol O.

, h=79 и 80 соответственно. Эти сигналы передаются на 79-й и 80-й входы ФВДС 6, конкретнее на восстановитель дискретных сообщений 9, в разные моменты времени. В соответствии с использованным принципом взаимной однозначности байтов и ШПС на выходе устройства 9 восстанавливаются байты дискретных сообщений N и О в виде (5). Сопрягающее устройство формирователя 10 (оно может работать по стандарту USB 2.0 или любому другому более быстродействующему стандарту, который может быть создан в будущем) обеспечивает оптимальную передачу сообщения на выход, потребителю. Работа по передаче дискретного сообщения NO с входа на выход системы завершена.Decider 5 generates recognition signals based on ACF peaks

, h=79 and 80, respectively. These signals are transmitted to the 79th and 80th inputs of the FVDS 6, more specifically to the restorer of discrete messages 9, at different times. In accordance with the principle of one-to-one bytes and SPS, the bytes of discrete messages N and O are restored at the output of device 9 in the form (5). The interface device of the driver 10 (which may work according to the USB 2.0 standard or any other faster standard that may be created in the future) ensures optimal transmission of the message to the output, the consumer. The work on transferring the discrete message NO from the input to the output of the system is completed.

When using a coding system with g ₁ symbols, the form must include g=g ₁ NPS, it is required to group discrete messages into blocks of g ₂ =log ₂ g ₁ (rounding up to the nearest integer) elements.

6. Rationale for the achievement of the technical result

The technical result consists in increasing the speed with a simultaneous increase in the energy secrecy of the system for transmitting discrete messages in the presence of noise in an optimal way and energy efficiency due to the simplification of the design, as well as in the efficient use of the frequency band.

In [6, p. 9] presents a formula that determines the NLS detection time. In the claimed method and system, the detection operation is not carried out, so the performance is higher than in the prototype. The absence of devices for searching and synchronizing the SHPS simplifies the design and reduces power consumption.

The covert transmission of messages to the user via CN 3 is ensured by the transmission of NPS (ensemble codes) at a level below the noise level (ρ ² <<1, where ρ ² is the ratio of NPS powers and interference) [6]. The signal-to-noise ratio at the output of the SF or correlator with optimal reception is 2⋅B times greater than at the input [6, p. 6]. It is necessary to use ensemble codes with base B>>1 (codes with B=N=30 are presented), since the larger the base, the greater the excess over noise and the higher the secrecy [6, p. 9]. When attempting unauthorized access, an unauthorized user will need to use special methods and devices to decide whether any signals are transmitted, or there is only noise [6, p. 6]. The use of a combination of SFs allows for optimal detection and discrimination of signals in the presence of noise [6].

The increase in bandwidth efficiency is due to the following circumstances. Comparison of the bandwidth values of the signals in the prototype and in the example of the claimed system. Let ΔF ₁ =13/T - frequency band KB in the prototype; ΔF ₂ =30/(8⋅T) - frequency band code from the submitted form with N=30 and a duration equal to a byte (g ₂ =8) of the input signal; ΔF ₃ =30/(4⋅T) is the frequency band of the code from the form with half the duration, as in FIG. 1 (c), 2 (b). Then the ratio of the bands is G ₁ =ΔF ₂ /ΔF ₁ ≈0.29 and G ₂ =ΔF ₃ /ΔF ₁ ≈0.58. Therefore, the claimed system in this case occupies 29% of the bandwidth relative to the prototype for the case when the NPS is located at an interval equal to the duration of a byte, and 58% of the bandwidth when the NPS is two times shorter. There are significant savings. In an example of the claimed system, a bandwidth directly proportional to N and inversely proportional to g ₂ is required.

7. Options for the application of the claimed method and system

The claimed method and system can be applied when the source of discrete input messages are signals from sensors or a database of a plurality of objects. Such information can be transmitted by the claimed system to the consumer via CS 3 (for example, by twisted pair, FOC, via radio channel), while the function of covert transmission of discrete messages is implemented, including in the presence of noise and interference. CS 3 can use various physical media.

The claimed device can be used in remote control systems for objects designed to move and perform the required operations in various physical environments. Objects can be, for example, robotic systems, aircraft and swimming vehicles.

It is possible to transmit discrete messages at the noise level in the same frequency range and time interval as high-level signals that are significantly higher than the noise level. This increases the total volume of messages sent to the consumer per unit of time.

The method and system can be used in the case of transmission of pre-encrypted discrete messages [21] or messages with redundant coding.

8. Power supply, connectors

Energy supply is determined based on the use case of the system, for example, from stationary sources or from small batteries. The types of connectors also depend on the use case (types of connectors for sources and output consumers, types KS 3). When the source and destination of messages are computer hardware, USB-type connectors, plugs and high-frequency connectors (preferably with shielding and grounding) can be used.

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Claims (38)

1. A method for transmitting input discrete messages that consist of elements in the form of logical ones or zeros, or of positive and negative logical ones, including on the transmitting side the conversion of these elements of one type into a wideband signal and the conversion of elements of a different type of this discrete message into another wideband signal, the transmission of this sequence of broadband signals over a communication channel, the implementation of a typical transceiver of broadband signals, followed by the operation of their matched filtering on the receiving side, the comparison of the received signal with a threshold level, characterized in that, as new features, such operations as selection of g ₁ different elements for the discrete message coding system, numerical enumeration of these elements from zero to (g ₁ -1), grouping consecutive elements of the input discrete message into blocks of duration T _b by g ₂ elements, where g ₂ is calculated by the formula g ₂ \u003d log2 g ₁ rounded up to the nearest integer, or setting the parameter g ₂ to a value equal to the number of elements in the block of the input encrypted discrete message or message with redundant coding, while g ₁ =2 ^a , where a=g ₂ , selection g=g ₁ of different noise-like signals, the level of side peaks of the autocorrelation and cross-correlation functions of which is not more than positive numbers R and W, respectively, where R and W are numbers less than the largest value u _m of the modulus of autocorrelation functions of these noise-like signals, numbering of the selected noise-like signals sequentially with integers from 1 to g and arrangement in the form, establishment of a one-to-one correspondence between blocks of a discrete message, each of which corresponds to one of the numbers A, where 0≤A≤(g ₁ -1), and noise-like signals having the serial number A+1 in the form, the location of each of the selected noise-like signals within the interval T _b following the interval where the block of elements of the input discrete message is located, which is associated with the required noise-like signal, creating for blocks of grouped elements of the input discrete message a sequence of noise-like signals S _A+1 selected in the specified way, transmission of a sequence of noise-like signals through the propagation medium of a communication channel directly or using them as modulating signals, matched filtering of the received sequence by all g ₁ different matched filters, each of which is matched with one of the noise-like signals included in the form, comparison of each of the output signals of the matched filters with the corresponding threshold level U _n , which should be less than the largest values of the signals u _m at the output of the matched filters, when there is a noise-like signal at the filter input with which this filter is matched, at the same time the threshold levels U _n are selected greater than the largest of the numbers R and W, checking the excess of each of the signals received after performing the matched filtering of the received noise-like signals, numbered in the form by the numbers A+1, the value of the corresponding threshold level U _n , and in case of such an excess generation of recognition signals

received noise-like signal, recovery of each block of output discrete messages corresponding to the numerical value A, based on the recognition signal of the noise-like signal with A+1 serial number in the form, transmission of recovered discrete messages to the output. 2. The method according to p. 1, characterized in that the elements of the coding system may be represented as numbers or symbols, or combinations of symbols, or combinations of symbols and numbers, or as multimedia files. 3. The system for implementing the method for transmitting discrete messages contains a generator of noise-like signals, a communication channel, a matched filter, a decision device, characterized in that, as new features, converter of input discrete messages, shaper of output discrete messages, and the input of the converter of input discrete messages is connected to the input of the system for transmitting discrete messages, the converter of input discrete messages contains g ₁ outputs, which are connected respectively to the same number of inputs of the generator of noise-like signals, the output of this generator is connected to the input of the communication channel, the output of which is connected to the input of a matched filter containing g ₁ outputs connected to the same number of inputs of the decisive device having g ₁ outputs connected to the same number of inputs of the generator of output discrete messages, the output of which is connected to the output of the entire system, while the generator of noise-like signals is a functional group of g=g ₁ coders of the ensemble of noise-like signals or signals based on them, satisfying such conditions that the level of side peaks of the autocorrelation function of each of the signals does not exceed a positive number R, where R<u _m is the largest value of the autocorrelation functions of these noise-like signals, the level of side peaks of the cross-correlation function of each noise-like signal with all other (g-1) generated noise-like signals also does not exceed a positive number W, where W<u _m , g inputs of code generators of an ensemble of noise-like signals or signals based on them are the inputs of this functional group, the outputs of the coders of the ensemble of noise-like signals or signals based on them are connected in parallel and constitute the output of this functional group, the matched filter is a functional group of g matched filters, the inputs of which are connected in parallel, the impulse responses of each of the matched filters are optimal for one of the different signals of the noise-like signal generator, the inputs and outputs of each of these matched filters are the inputs and outputs of this functional group, the decision device for analyzing the output signals of each matched filter is a functional group of g ₁ decision devices, the inputs and outputs of which are the inputs and outputs of this functional group. 4. The system according to claim 3, characterized in that The converter of input discrete messages contains a logical device of the converter and an interface device of the converter, the input of the interface device is connected to the input of the converter of input discrete messages, the output of the interface device is connected to the input of the logical device of the converter, g outputs of which are connected to g outputs of the converter of input discrete messages; the logical device of the converter is made on logic elements or programmable logic matrices or on its variants; the interface device of the encoder is made on passive elements, or on transistors, or on microcircuits, or in the form of a universal USB serial bus. 5. The system according to claim 3, characterized in that the discrete output message generator contains a discrete message element restorer and a driver interface device, the inputs of the discrete message element restorer are connected to the inputs of the output discrete message generator, the output of the discrete message element restorer is connected to the input of the converter interface device, the output of which is connected to the output of the output discrete message generator; the restorer of the elements of discrete messages is made on the elements of discrete circuitry or on programmable logic matrices or its variants or in the form of a storage device; the driver interface device is made on passive elements, or on transistors, or on microcircuits, or in the form of a USB universal serial bus. 6. The system according to claim 3, characterized in that generators of codes for an ensemble of noise-like signals or signals based on them are made in the form of devices based on surface acoustic waves or elements of discrete circuitry or in the form of a memory device or on programmable logic matrices or its variants for direct transmission over a communication channel; generators of codes of an ensemble of noise-like signals or signals based on them are made in the form of devices for generating codes and signals based on them and in the form of a modulator of carrier oscillations for transmission over a communication channel, and these codes and signals are modulating signals. 7. The system according to claim 3, characterized in that a communication channel is a combination of technical means, such as a modulator, transmitter, receiver, demodulator, and a physical medium, such as a gas, or a liquid, or a solid, or a vacuum; the communication channel is a wired electrical communication line, or radio communication, or a sound acoustic communication channel, or a light optical communication line; the communication channel is made in the form of conductors of circuit elements, or a fiber-optic cable, or a coaxial cable, or a waveguide, or an audio duct, or a twisted pair, or a radio channel for terrestrial or satellite communications.

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