Method of generating codes for generating signal ensembles in telecommunication networks

FIELD: radio engineering, communication.

SUBSTANCE: method of generating codes for generating signal ensembles involves generating a source code of N≥4 elements, a number K≥1 of codes of N elements to be generated, as well as a target function for a set of L states of the code elements, and corresponding values of given signal parameters, characterised by an array of states of L×N×K peaks on N×K levels, connected by edges, wherein each of the L states is the initial state; generating codes; selecting a path with the extremum value of the target function, after which each generated code is assigned a symbol which corresponds to the edge of the path with the extremum value of the target function, and selecting 2≤M≤K codes with the maximum value of the ratio of the amplitude of the central peak of the autocorrelation function to the magnitude of the amplitude of the maximum lateral peak of the autocorrelation function and the minimum duration of the section of the autocorrelation function between the point of the maximum of the central peak and the point where the autocorrelation function becomes zero for the first time.

EFFECT: high jamming resistance of signals generated based on corresponding codes.

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The invention relates to the field of radio, namely the technique of generating code to implement multiple access and transmission of M-ary broadband signals, and can be used for the formation of the generated code information of the alphabet, in which each element of the alphabet corresponds to a number of bits dependent on the dimension of the alphabet M Also it can be used to separate the different subscribers in the system of information transfer based on the assignment of one or more codes to each user. The invention can also be used in communication systems, M-ary orthogonal stochastic broadband signals in order to increase their protection and energy efficiency.

The known communication system using M-ary orthogonal wideband signals[1], [2].

The known method of forming a modified Walsh codes according to the patent EUROPATAT EP 0952678 A1, publ. 27.10.99 [3]. The method includes the following steps. Specify the number of M generated by the modified code, define a set of orthogonal Walsh codes and the corresponding complementary codes, and the number of Walsh codes is also equal to M, multiply each of the set of orthogonal Walsh codes to corresponding to plementary code and thus, ensure that the value of the modulus of the first side peaks of the autocorrelation function is less than or equal to half the length of the modified code.

The disadvantage of this method is that the signals obtained on the basis of formed in accordance with the way the codes are relatively low immunity. This is because the possible number of modified Walsh codes are limited in length codes Walt.

Also known formation method according to patent US 7876845 B2, publ. 25.01.11 [4]. The method includes the following steps. Form many signals with overlapping spectra in the frequency domain, each of the signals contains many of the amplitude component and the multiple phase component, a pseudo-random manner assign a value to each of the phase component of many phase component for each signal in the frequency domain transform many signals in the frequency domain into the set of signals in the time domain, producing the orthogonalization of the obtained set of signals in the time domain and get lots of pairwise orthogonal signals in the time domain, transmit and/or receive information with the extension of the spectrum, and use it in lots of pairwise orthogonal signals in the time domain, characterized is, for example by transferring them weak property cyclostationarity.

The disadvantage of this method is sufficiently large value of the ratio of the peak power of the generated signal to the average power (peak factor).

The closest to the technical nature of the claimed invention is a method of generating codes for patent US 7587660 B2, publ. 08.09.2009 [5].

The closest analogue includes the following steps: pre-form source code of N≥4 elements, the number K≥1 codes of N elements, being formed, as well as the target function for the set of L States code, and the corresponding values of the set of signal parameters, characterized by a lattice of States of L×N×K vertices on the N×K levels, connected by edges, with levels N×(k-1)+1, where k=1, 2, ..., K - number subject code generation, each of the L state is the initial form codes, which are sets of edges emanating from a vertex at level N×(k-1)+1 and passing through the levels with increasing index N×(k-1)+i, where i=1, 2, ..., N, alternative paths, for which at each level N×(k-1)+i calculate accumulation of the target function of the number of alternative paths ending at the vertices with the same condition l, where l=1, ..., L, allocate the path with the extreme value of the objective function, and then assign each generated code SIM is ol, corresponding to the selected edge of the path included in the top-level N×(k-1)+i, removed from the lattice States ribs alternative ways that are not in the selected path, at each level of the tops of the N×(k-1)+l objective function zero for the computation of the objective function take into account the previously generated codes.

Disadvantages closest analogue are relatively low resistance to intentional interference, limited ability to generate signals with non-deterministic structure, the absence of selection codes from a set formed in accordance with a given criterion. The deficiencies noted are due to the fact that in the method according closest analogue does not take into account the relationship between the modulation and coding used in the communication system, and that as a result of passage through the bars of the States in the nearest analogue to simultaneously form the L-based code L source code, which imposes on codes generated significant restrictions.

The purpose of this invention is to develop a method of generating code to generate random ensembles of signals in telecommunications networks with linear, non-linear modulation types, including memory. These ensembles must have given intercorrelation properties and to improve noise immunity and energy eff is aktivnosti radio transmission of information. This is achieved through the choice of the objective function, taking into account the relationship between the modulation and coding used in the communication system and an improved approach to generating codes (formation of source code randomly and the selection of only one initial state at each level of the tops of the N×k-1)+1.

This objective is achieved in that in the known method of generating codes, namely, that pre-form source code of N≥4 elements, the number K≥1 codes of N elements, being formed, as well as the target function for the set of L States code, and the corresponding values of the set of signal parameters, characterized by a lattice of States of L×N×K vertices on the N×K levels, connected by edges, with levels N×(k-1)+1, where k=1, 2,... , K - number subject code generation, each of the L state is the initial form codes, which are sets of edges emanating from a vertex at level N×(k-1)+1 and passing through the levels with increasing index N×(k-1)+i, where i=1, 2, ..., N, alternative paths, for which at each level N×(k-1)+i calculate accumulation of the target function of the number of alternative paths ending at the vertices with the same state l, where l=1, ..., L, allocate the path with the extreme value of the objective function, and then assign each of the generated code symbol, corresponding to the selected edge of the path included in the top-level N×(k-1)+i, removed from the lattice States ribs alternative ways that are not in the selected path, at each level of the tops of the N×(k-1)+1 objective function zero for the computation of the objective function take into account the previously generated codes, ask pre-allowed transitions in the lattice States. Edges only connect vertices corresponding to the allowed transitions. Source code form randomly. At each level of the tops of the N×(k-1)+1 arbitrarily choose only one initial state. Of all the alternative paths to the computed value of the objective function allocate only one alternative path with an extreme value of the objective function at the level of the N×k. After the formation of the K codes calculate for them the additional function of autocorrelation and choose 2≤M≤K codes with a maximum value of the ratio of the amplitude of the Central peak of the autocorrelation function module and a maximum amplitude of the side peak of the autocorrelation function and the minimum duration of the plot of the autocorrelation function between the point of maximum of the Central peak and the point at which the autocorrelation function for the first time vanishes. Allowed transitions in the lattice conditions set in accordance with the selected modulation type of the signal. N is an even number. The target function is, s is chosen under the condition of equality to zero of the value of mutual scalar products between signals generated ensemble. As signal parameters select the phase, amplitude, and frequency.

Thanks to the new essential features in the proposed method allows to generate random ensembles of signals in telecommunications networks with linear, non-linear modulation types, including memory. These ensembles have given intercorrelation properties. Their use helps to increase immunity and energy efficiency of the radio transmission of information due to the choice of the objective function, taking into account the relationship between the modulation and coding used in the communication system and an improved approach to generating codes (formation of source code randomly and the selection of only one initial state at each level of the tops of the N×(k-1)+1. Accounting communications modulation and coding used in the communication system also allows, for example, to reduce the level of out-of-band radiation signal based on the generated code. And thanks to the choice at each level of the tops of the N×(k-1)+1 only one initial state eliminated a number of restrictions on the formation of codes closest analogue that increases the stability of the signals generated on the basis of relevant codes, to intentional interference.

Stated the manual is illustrated by drawings.

Figure 1 shows the lattice States.

Figure 2 shows the spectra of signals with MSK and BPSK modulation.

Figure 3 shows waveforms of signals with GMSK modulation.

Figure 4 shows an example of generating orthogonal codes using the claimed method using a convolutional encoder.

Figure 5 shows a sample schema transmitting device using the inventive method.

Figure 6 shows a sample diagram of a receiving device using the inventive method.

The implementation of the inventive method is explained as follows. Let the source code needed to generate other codes in accordance with the claimed method is a binary bipolar and is generated randomly. The source code may not be binary, but the case of the binary code of the most simple to explain. The length of the source code must be N≥4 elements, since the generated code of the two elements does not make sense to apply, in particular, in the information transmission of broadband signals, and for odd N the scalar product between generated based on the source codes may not be equal to zero (orthogonality condition). Thus, when N=3 is not possible to use during transmission of orthogonal signals with BPSK modulation (or FM-2).

Codes are generated by the ocher is di and for generating each of the following code as the original accepted the original source code and generated on the basis of codes. Thus, at each iteration, generate the code number of the source code is incremented by 1.

In accordance with the claimed method is expected to generate codes using items as modulating parameters for phase (here the code elements can be, for example, "0" and "1"), the amplitude and frequency of oscillation, called modulated parameters (for different types of modulation can be either 1 or 2 adjustable parameter), the obtained signals with zero mutual scalar products, i.e. (Si, Sj)=0, i≠j.

The source code is also included.

The amplitude, frequency and phase when the selected type of modulation can take a number of L values or States. So when BPSK modulation L=2, since the phase takes the values of 0 and 180 degrees. As the type of modulation can be selected FSK-modulation, GMSK-modulation [1], BPSK modulation or other modulation types. The selected type of modulation depends solely on the destination of the communication system, in which it will be used.

For generating codes in accordance with the claimed method introduces the objective function that is a set of functions, each of which is equal to the dot product between the signal derived from the D code elements corresponding to one of the alternatives to the output paths in the lattice States and signal obtained on the basis of D elements of one of the source code. The number of functions included in the target, is determined by the number of source code at a given iteration generate codes.

Initially, the objective function for each generated code equal to zero (all of the features included in the target of zero). Further, after generating the code, the value of its member functions may deviate from zero.

The claimed method involves the existence of a relationship between the system information transfer type of modulation and coding for each element in the generated code. This link is provided by the introduction of lattice States of the L×N×K vertices on the N×K levels, connected by edges. At the levels of N×k-1)+1, where k=1, 2, ..., K-number subject code generation, one of the L state is the initial (i.e. from this point lattice begins generating current code). What state is initial, is determined arbitrarily. Initial state, as mentioned above, corresponds to zero value of the target function.

Thus, each code is characterized by a set of edges connecting the N vertices of a lattice of States, each of which is modulated parameter signal generated on the basis of this code, shall take one of the L States. Each of the edges connecting vertices between them corresponds to the element forms the generated code. For example, it can be equal to "1", if the node to which it belongs, is above the vertex from which it comes, and to -1 if the vertex on which it is located below the top, from which it comes. This condition may occur in the frequency, if in accordance with the claimed method are formed wideband signals (PSS) with BPSK modulation. Generating codes in the formation of ensembles of signals with different modulation types can be made with or without memory. When the memory parameter signal when the transition edge from one vertex to another takes is not only depending on the condition corresponding to the top, which includes a rib, but from the state corresponding to the vertex from which the edge originates. How account for the memory, then more will be said in a specific example.

Alternative paths in the lattice States - C≥2 sets of edges emanating from a vertex at level N×(k-1)+1 and passing through the levels with increasing index N×(k-l)+i, where i=1, 2, ..., N. Moreover, at each level N×(k-1)+i for alternative ways to calculate the accumulation of the target function (the objective function value for all edges included in an alternative way, summarize). Highlight alternative ways, with the extreme value of the objective function. Then instead of saying, "selected path" Boo who has been used the expression "survivor path", since this terminology is well established (in particular, it is used in the description of the optimal decoding algorithm Viterbi in [1]).

Lattice States are depicted in figure 1. The vertices of the lattice States are marked with 1, and edges connecting the vertices, figure 2. You can see that the peaks of the previous level of the lattice States not connected with all vertices of the next level of the lattice States, but only permitted. What tops are permitted to connect the ribs with some top at the previous level, is determined by the type of modulation, that is, the law changes the modulated parameter (or modulated signal parameters).

Figure 1 is a lattice States with the total number of vertices is L×N×K, for ease of presentation is divided into To arrays (the number of generated codes) with the number of vertices but horizontal N (the number of elements in each formed after passing through the lattice States code) and with the number of States item code L vertically (but the number of modulated values of the parameter or modulated signals formed on the basis of the ensemble of codes). L States for the index of the element generated code n (n=1, ..., N) form the level index n.

Each vertex of the lattice state is uniquely determined by three indices: l=1, ..., L, k=1, ..., K and n=1, ..., N, where the l - the index which determines the value of the adjustable parameter (or modulated parameters) signal and the number of States in the lattice of States, k is the index that identifies the number generated by the current passing through the lattice States code, n is the index that identifies the item number form of the k-th code. The vertices of the lattice in General are referred to as Ukl(n). The vertices of the lattice index Ukl(1) correspond to the chosen initial state when a user-defined l for all k.

Figure 3 corresponds to the bold line. This line indicates the path through the lattice of States, which corresponds to the generated k-th code. Edges included in line 3 is selected, since each of these edges included in the surviving path (alternate path with an extreme value of the objective function). By the time when the k-th code is fully formed, all edges that are not included in the surviving path will be removed from the lattice States.

The value of the index l to vertex U1l(1), which begins on line 3 (see figure 1), is chosen arbitrarily. From figure 1 it is seen that two sets of ribs: U11(1)-U12(2)-U11(3) and U11(1)-U1l(2)-U11(3) to form an alternative path. For edges that belong to these alternative ways, with the accumulation is calculated objective function. Let when generating code survivors are considered to be the path with the minimum the value of the objective function and let alternative way U 11(1)-U12(2)-U11{3) has a minimum value of the objective function (the function that is included in the target, the minimum value and tend to zero). Then the generated code assign a symbol (for example, "1" or "-1", which may correspond to the situation when the type of modulation generated signals - PSS BPSK), corresponding to the rib U12(2)-U11(3). Rib U1l(2)-U11(3)not included in the surviving path is removed from the lattice States. After this process is repeated up until the 1st code of length N will not be fully developed. After the 1st code will be generated, the objective function will change - it is, in addition to the source code will now consider 1st the generated code. At the level of k×(N-1) in the lattice of States can be more than one surviving path. However, at the level of k×N survivors will be named only one alternative path with a minimum value of the objective function (as in one passage through the bars of the States in accordance with the claimed method must generate only one code). If the k×N, the minimum value of the objective function has a number of alternative ways greater than one, then the surviving path can be defined arbitrarily. For example, surviving by might be called an alternative path, ending at the top with the condition, the index l of which a minimum cf the di all alternative paths with the same value of the objective function. The generated code will contain only characters that correspond to the edges of the surviving path at the level of k×N when the sequence of edges from left to right.

The described process is repeated until then, until it formed the ensemble of codes. The numbering of generated codes is arbitrary.

In General, the process of generating codes can be represented in the form of the algorithm (even when this lattice States and its structure has been specified):

1. The initial data are set to zero objective function, an arbitrary index l=1, ..., L the initial condition and the original random code of length N. the Variable i is set equal to one. Set the index of the generated code k equal to one.

2. Searches for alternative paths starting in the initial state of the lattice States and passing through levels of increasing index N×(k-1)+1, ..., N×(k-1)+i.

3. At the level of the N×(k-1)+i for alternative ways (for all edges included in the alternative path of accumulation) calculate the target function.

4. The survivors called alternative path with the minimum objective function value.

5. Generated k-th code assigns the character corresponding to the edge of the survivor path, a part of the top-level N×(k-1)+i.

7. Of lattice States remove those edges of alternate routes that are not included in the surviving path. Meant the e variable i is incremented. Then the process is repeated, starting with section 3, up until the k-th code will not be generated. Already computed for the edges of the survivor paths of the values of the objective function to re-calculate is not required, if you add these values in memory. It is important to note that at the level of the lattice of States N×k survivor is only one alternative path with the minimum objective function value, and the generated code will eventually contain only characters that correspond to the edges of this the only survivor path, the sequence of edges from left to right.

8. Increase the index generated code k per unit. Zero objective function and update it, given it previously generated codes.

9. Then the process is repeated, starting with 1, while the whole ensemble of codes will not be generated.

After the formation of the ensemble of codes for all the generated codes are calculated such characteristics of their autocorrelation functions, as the ratio of the amplitude of the Central peak of the autocorrelation function module and a maximum amplitude of the side peak of the autocorrelation function and the duration of the plot of the autocorrelation function between the point of maximum of the Central peak and the point at which the autocorrelation function for the first time vanishes. Preferred are the maximum of the first value and the second minimum.

Characteristics and tocorrelation functions [1] generated codes are computed for the reason that not all generated codes of the characteristics of the autocorrelation function may be acceptable for use in real communication systems. Often the task is to choose M best code and work with them, and the other codes thrown.

The objective function, using calculations which are generated codes can include aggregate functions, equal to the reciprocal of the scalar works between the signals generated on the basis of the generated codes, and signals derived from the source code, and in accordance with the claimed method it is equal to zero. However, the objective function may include a set of functions is equal to the ratio of the amplitude of the Central peak of the autocorrelation function module and a maximum amplitude of the side peak of the autocorrelation function or the duration of the plot of the autocorrelation function between the point of maximum of the Central peak and the point at which the autocorrelation function for the first time becomes zero or peak factor [1] for signals generated on the basis of the generated codes. The choice of the objective function are not limited to the above options.

Let the objective function, using calculations which are generated codes of zero and includes a set of functions equal to the reciprocal of the scalar works between rings is Lamy, formed on the basis of the generated codes. Next, you will be saying is that the target function is selected taking into account the orthogonality of the signals generated on the basis of the generated codes. It is known that the orthogonal correlation signals at zero offset is zero. Thus, in the set of characters that can be assigned to the generated code must be either positive and negative numbers, the sum of the products which the two orthogonal signals at zero shift will give zero (this explains the necessity of the conditions under which N is an even number), or frequency, ensuring the orthogonality of the codes of the ensemble for each symbol interval, and the conditions of orthogonality in frequency is known from [1], or the initial phase, ensuring the condition of orthogonality of all signals in the ensemble. In the latter case, the obvious example is the orthogonality of sine and cosine on the period. Sinus can be represented as a cosine with an initial phase of π/2.

Thus, the symbol assigned to the code that corresponds to one or more of its parameters: the amplitude and/or phase and/or frequency. Moreover, the parameters will be, depends on a certain type of modulation. The modulated signal parameters corresponding to the index l of the lattice States may change when change is drop l from 1 to L as regular, and irregular law.

One of the advantages of the type of modulation signals generated based on the generated code, for example, for modulation MSK - reducing out-of-band radiation, which is reflected in figure 2, where a comparison of the width of the signal spectrum for cases MSK - BPSK-modulation. From figure 2 it is seen that, for example, when the spectral density of the signal energy -7,5 dB/Hz spectral width MSK signal ΔfMSKless than the width of the spectrum of the BPSK signal ΔfBPSKabout 0.2 kHz.

When modulation GMSK modulated parameters are the initial phase and frequency. The frequency-dependent index l vertices Ukl(n+1) (see figure 1), which includes the selected edge, and an initial phase, in addition, also depends on its previous value at the vertex Ukl(n)from which the selected edge comes. Example GMSK signal is shown in figure 3.

What vertices in the lattice States are permitted to connect the ribs with some top at the previous level, may also be determined by the structure of the convolutional encoder [6], which includes the shift register with a single input and the number of outputs is greater than one. Each output is the sum modulo 2 of some bits of the shift register. The number of bits of the shift register and the number of outputs of the convolutional encoder is determined by the requirements of pomekhoustoichivost and speed of information transmission in the communication system.

The used modulation is possible to choose the phase manipulation of the values of the modulating parameter of the +1 and -1 (+1 corresponds to the value of the initial phase of the signal duration information symbol, is equal to 180 deg., and -1 is the value of the initial phase of the signal is equal to 0 deg.), and what value will be assigned to the selected edge may depend, for example, depending on which figure appeared at the output of the convolutional encoder (0 or 1). 0 will correspond to -1 and 1 will correspond to 1. State of the convolutional encoder will determine the possible States of a code element in the lattice States. Convolutional encoder and an example of code generation with it is shown in figure 4.

Let convolutional encoder 4 contains 3 discharge (discharge encoder footnote 4.1), and the bits at the output obtained by the addition in the adder modulo 2, which figa designated as 4.2, the contents of his two bits (namely, the 1st and 3rd). The output of the encoder is thunk "0" to "-1" (footnote 4.3), while the "1" remains "1". It is necessary to generate code that is orthogonal to the original (using the objective function, taking into account the orthogonality of the signals in the ensemble).

Let the set of source code that contains the following elements:

11-1-1.

Let also arbitrarily chosen initial state (is and figb state in the lattice of States correspond to the possible States of the convolutional encoder, which number is 8, because the encoder is a three-digit) "011", whose index l (counting from the top) - 4. In this initial state at the output of the convolutional encoder will be "1" (the sum of the 1st and 3rd digits modulo 2).

The objective function taking into account the orthogonality of the signals generated on the basis of the generated codes and orthogonal codes themselves, because it uses a BPSK-modulation), will be calculated as follows (in accordance with rule calculation of the correlation function for two signals):

R0(1)R0(2)R0(3)R0(4)xxxxR1(1)R1(2)R1(3)R1(4)a+bmtext> +c+d=z

where R0(n) determines the value of an element of the source code with index n, a R1(n) determines the value of the element with index n generated when passing through the lattice States code. For orthogonal codes, the z value is essentially a correlation value codes with zero shift, and it must be 0.

When generating code for creating ensembles of signals in telecommunications networks, it is possible to change the principles described in the claimed method.

An example of this below.

So, R0(1) is equal to 1. If the product of R0(1) and R1(1) gives 1. Since z is orthogonal codes, as mentioned above, is 0, and the objective function in this example is selected taking into account the orthogonality of the generated code, the product of R0(2) and R1(2) should be equal to -1, to compensate for when the summation of the product of R0(1) and R0(1)equal to 1.

From the current state of the convolutional encoder "011" may go in 2 States (these States are allowed to state "011"): "001" (when applying to input the encoder "0") and "101" (when applying to the input of coder "1"). Therefore, vertices (footnote 5 on figb) U14(1) and U12(2) state "011" and "001", respectively, and a vertex U14(1) and U16(2) state "011" and "101", respectively, are connected by edges (footnote 6 on figb). Considering the fact that the "0" next will be converted to "-1"and "1" will remain "1", the output of the encoder is in state "001" will give "1" (R1(2)=1), and a status of "101" is "-1" (R1(2)=-1). Next, you must calculate the objective function for edges between vertices U14(1) and U12(2)and U14(1) and U16(2). When R1(2)=-1 the product of R0(2) and R1(2) to give "-1", and if R1(2)=1 the product of R0(2) and R1(2) will give a "1". When summarizing the works of R0(2) and R1(2) work with R0(l) and R1(1) (the objective function is calculated by accumulation) is the objective function value or "2" for edges between vertices U14(1) and U12(2), or 0 for edges between vertices U14(1) and U16(2). Since z=0 for the edge between vertices U14(1) and U16(2), it is necessary to allocate the specified edge (highlighted edge on figb indicated by footnote 7), and the generated code to assign the symbol R1(2)=-1. In this case, the allocation of ribs similar to the removal of fins of alternative paths that are not included in the surviving path, described in the claimed method.

In the next step, no C is achene, what is the symbol R1(3) ("1" or "-1") will be assigned to the generated code, because the target function is adding to its value (after assigning the generated code R1(2)=-1 is "0") "1" or in any way deviates from 0. Vertex U16(2), namely it leads allotted edge, connected by edges with two vertices (including changes of state of the encoder is fed to its input "0" or "1") - U13(3) and U17(3). Since the objective function in any case will not be equal to 0, it is possible to allocate each of the two above-mentioned ribs. Let the selected edge between vertices U16(2) and U17(3). Then the objective function takes the value "-1", and the generated code will be assigned the symbol R1(3)=1. Now the selected edge will lead in the top of the U17(3).

Vertex U17(3) are connected by edges with two vertices (including changes of state of the encoder is fed to its input "0" or "1") - U14(4) and U18(4). It is necessary that the objective function has adopted a zero value for the last of the selected edge. This is possible if the product of R0(4) and R1(4) will give a "1"that the sum of the balance value of the objective function obtained in the previous step. In accordance with this requirement, you must select an edge between vertices U17(3) and U18(4)by setting the generated code R1(4)=-1.

First the th generated orthogonal code in relation to the original. So the value of their correlation at zero offset will be 0:

11-1-1xxxx1-11-11+(-1)+(-1)+1=0

Figure 5 and 6 demonstrated examples of possible implementations of the transmitting and receiving devices using the inventive method.

Figure 5 shows a transmitting device. To the input of the data buffer (DB) 8.1 receives the input data (V×D) in the form of a bit stream. From the buffer data is read and fed to the input of the convolutional encoder (SC) 8.2, where the addition of redundant symbols. From the output of the convolutional encoder encoded data is fed to the input of the interleaver (P) 8.3, where the permutation bits so that adjacent bits received at the input of the interleaver, were separated by some number of bits. This is necessary in order to make the package errors (after transmission over the communication channel)in a single error at the output of deteremines, which are easier to correct. From the output of the data interleaver in the form of a bit stream is fed to the input of Converter bits/symbol (TRB/S) 8.4, in which the combination occurs a certain number of bits in one symbol. In the interleaver symbols (PS) 8.5 is the alternation of transmitted symbols. In block 8.6 stored ensembles of M-ary (M is the number of codes in the ensemble) orthogonal codes - IOC (target function is selected taking into account the orthogonality of the signals in the ensemble), generated using the inventive method. When the input unit 8.6 information symbol is replaced symbol corresponding to its value (based on the one or more communication sessions) code. At block 8.6 served well as a control signal for changing ensemble (CA to CL) (principles of its formation will be described hereinafter). In block selection mode (WRR) 8.7 the following options transfer information:

on all subcarriers (signal transmission on multiple carriers) transmitted the same signal formed on the basis of one of the codes corresponding to one information symbol;

at each subcarrier transmitted its signal formed on the basis of one of the codes corresponding to one information symbol from a number (equal to the number of subcarriers for transmission, and the formation of m) are sequentially transmitted information symbols.

It is obvious that in the first case, higher noise immunity, and the second transmission rate information.

In block 8.9 formation signals (FS) R1(nT), ..., Rm+1(nT) based on the submitted input codes, and n is the number of the current period of the signal and T is its duration. In block 8.12 is the inverse fast Fourier transform - OBPF (taking into account the fact that on one of the subcarriers can be transmitted binary bipolar sequence supplied from the block generator singaporelovelinks.com (SHG) 8.8) [2], resulting in the total signal. Principles of formation of singaporelocalnews described in detail in many works, in particular in [1]. In the generator carrier frequency (GNC) 8.10 formed sinusoidal high-frequency oscillation. If the system works with a pseudo-random frequency [7], GNC may also be submitted control signal for jumps but the frequency (CONDITION for MF). When passing through the Converter Gilbert (PG) 8.11 [8] high-frequency sinusoidal oscillation is converted into high-frequency cosine oscillation. The signal received from the output of the block 8.12, the modulator (M) 8.13 is transferred to the frequency of the high frequency oscillations. Formation of two quadrature, which are further summarized in the block 8.14. In block 8.15 (d / a Converter or DAC) which assumes the conversion of the digital signal, coming from the output of the block 8.14, in analog. Block 8.15 analog signal is supplied to a lowpass filter (LPF) 8.16, the power amplifier (PA) 8.17, and then to the transmitting antenna 8.18.

Figure 6 shows the receiving device. At the receiving antenna 9.1 of the communication channel receives a transmitted signal. Next it passes through the bandpass filter (PF) 9.2, the power amplifier 9.3 and is supplied to an analog-to-digital Converter (ADC) 9.4 where it is converted into digital form. In the generator carrier frequency 9.5, similarly as it happens in the sending unit, figure 5, is formed sinusoidal high-frequency oscillation, which, acting on the Hilbert Converter 9.6, is converted into high-frequency cosine oscillation. If the system works with a pseudo-random frequency, THEMES can also be submitted control signal for jumps in frequency. In the demodulator (DM) 9.7 adopted digitized signal is removed from the carrier frequency, that is, the demodulation procedure. In block automatic gain control (AGC) 9.8 is strengthening or weakening of arriving at its input fluctuations to acceptable values. Adjusted the amplitude of the signal at the block fast Fourier transform (FFT) 9.9, where the selection of all components of its subcarriers. Parallel block 9.10 g is nearwest reference singaporelovelinks.com, similar to the one that is generated in the transmitting device. In the evaluation unit parameters (OP) 9.11 by correlation reference singaporelovelinks.com with the accepted method of sequential search [9]) is set sync delay. Other possible algorithms and the synchronization circuitry described, for example, in [9]. Store ensembles of M-ary orthogonal codes 9.12 are generated using the inventive method ensembles of orthogonal codes used during this session. At block 9.12 control signal for changing ensemble (CA to CA). From the block 9.12 in accordance with the mode of operation of the communication system specified in the block 9.13 (examples of modes of operation have been described in the description of figure 5), the orthogonal codes are fed to the driver reference signals (FOS) 9.14, where they formed the basis of the signals RV1(nT), ..., ROPM(nT), similar to those that can be formed on the transfer. Box 9.14 reference signals are sent to the block 9.11, where the accumulated correlation of the reference signals adopted in accordance with the selected mode of operation of the communication system. Taking into account the calculated correlation block 9.11 evaluation of the phase and amplitude of the signal on the allocated subcarriers, then the control signals amplitude (CYA) and phase (suf) served on the blocks and 9.8 9.15 (block phase is Odstrani (AF)), respectively. Some schemes the phase and amplitude adjustment described in [10]. Box 9.15 is the phase adjustment for each of the selected subcarriers. Box 9.11 calculated on the period of the correlation of the reference signals with adopted J1(nT), ..., JM(nT), goes to block a decision on the maximum correlation (PMC) 9.16, where is defined what the signal was received. The principle of operation correlating receiver are described in detail in [1]. In block 9.17 converts decisions about the received signal in the corresponding (during the session) signal symbol (PRS). In block 9.18 is deteremine received symbols (DPS). Next, in block 9.19 characters are converted to bits (ORS/B), over which, in turn, block 9.20 is the operation deteremine. Output deteremines bit stream is fed to the input of the Viterbi decoder (DV) 9.21 [6], with which the stream of decoded bits is supplied to the buffer with the data 9.22. From the buffer with data received bits are read by the information recipient.

Using the inventive method of generating codes in the transmitter (figure 5) and the receiver (6) the device allows you to perform data transfer with change of ensembles of orthogonal signals. This feature provides increased stability to the formulation of simulation noise.

D. the I data transfer with change of ensembles of signals require the synchronization of pseudorandom generators 8.18 and 9.23. Blocks 8.18 and 9.23 (pseudorandom generators (gpsa)provide the source code for orthogonalization by the claimed method (GGS) - blocks 8.19 and 9.24 (the objective function in these blocks, in which in accordance with the claimed method codes are generated, selected, taking into account the orthogonality of the signals generated on the basis of the generated code). When the same source coming from blocks 8.18 and 9.23 input blocks 8.19 and 9.24, respectively, are generated identical ensembles of codes. Therefore, transmission and reception will be produced using the same ensemble of signals. The law of change of ensembles of signals can be determined arbitrarily. For example, changing ensembles of signals can be done once per day.

The possibility of implementing systems using the inventive method are not limited to the above example. Any blocks depicted in figure 5 and 6 can be eliminated, the sequence of blocks in the diagrams of the transmitter and receiver may also be modified.

Thus, the claimed method of generating codes for generating signals in telecommunication networks provides codes on the basis of which it is possible to obtain orthogonal signals, in particular, with BPSK modulation. Five codes for the sequence length N=16 is given below:

Here are 5 codes Walsh [11] for the same length of sequence:

Obviously, Walsh codes, and the contrast codes generated in accordance with the claimed method, possess a regular structure and, therefore, more susceptible to interference simulation.

Due to the increasing urgency of the task of creating a FSO communication systems, in particular, based on CDMA technology [12], the search and generation of signals with non-deterministic, pseudo-random structure becomes one of the main directions of development of the modern theory of communication. The claimed method helps to solve the problem. It is actually a much more effective alternative to the method of complete enumeration in search of signals with the desired properties. This allows to apply the well-known ensembles of signals and, thereby, in some cases to achieve high noise immunity and energy efficiency.

The claimed method can be used to generate codes for cellular communication systems, satellite systems for military secure communications systems and for other systems. Transmitting and receiving device of a communication system in which the claimed method is used, can be both stationary and mobile.

the LIST of INFORMATION SOURCES

1. Sklar, B. Digital communications. Theoretical basis and practical application. Ed. 2nd, Rev.: TRANS. from English. - M.: Publishing house "Williams", 2003. - 1104 S.

2. Had Soured J. Digital communication. TRANS. from English. Ed. DOS. - M.: Radio and communication, 2000. 800 S.

3. D.J.Richard et al. EP Patent N 0952678 Al, Digital modulation system using modified orthogonal codes to reduce autocorrelation sidelobes. Oct. 10, 1999.

4. P.D.Karabinis US Patent N 7876845 B2, Wireless communications systems and/or methods providing low interference, high privacy and or cognitive flexibility. Jan. 25, 2011.

5. J.S.Dyer et al. US Patent N 7587660 B2, Multiple-access code generation. Sep.8, 2009.

6. Grigoriev Wasigny modern foreign telecommunication systems: a Textbook YOU, 2007. - 368 S.

7. Borisov, V.I. and other Immunity of radio communication systems with expansion of the range of signals, the method of pseudo-random adjustment of the operating frequency. - M. :Radio and communication, 2000. - 384 S.

8. Brychkov Y.A., Prudnikov A.P. Integral transforms of generalized functions. M.: Nauka, 1977. - 287 S.

9. Fomin A.I. Synchronization of digital radio transmission of information. - M.: SCIENCE PRESS, 2008. - 80 S.

10. Kolosovsky E.A. pickup Device and signal processing. M: Hot line - Telecom, 2007. - 456 S.

11. Nikitin GI Application of Walsh functions in cellular communication systems with code division multiplexing: a manual / SUAI. SPb. 2003. - 86 C.

12. Newdev L.M. Mobile communications 3rd generation/edited Umoristi. - M.: the Series "Communication in business", ICSTI, LLC "Mobile is s communications", 2000. - 208 S.

1. The way to generate code for creating ensembles of signals in telecommunications networks, namely, that pre-form source code of N≥4 elements, the number K≥1 codes of N elements, being formed, as well as the target function for the set of L States code, and the corresponding values of the set of signal parameters, characterized by a lattice of States of L×N×K vertices on the N×K levels, connected by edges, with levels N×(k-1)+1, where k=1, 2, ..., Knumber subject code generation, each of the L state is the initial form codes, which are sets of edges emanating from a vertex at level N×(k-1)+1 and passing through the levels with increasing index N×(k-1)+i, where i=1, 2, ..., N,alternative routes for which at each level N×(k-1)+i calculate accumulation of the target function of the number of alternative paths ending at the vertices with the same condition l, where l=1, ..., L, allocate the path with the extreme value of the objective function, and then assign each generated code symbol corresponding to the edge of the path with an extreme value of the objective function that is a member of the top-level N×(k-1)+iremove from the lattice States ribs alternative ways that are not in the path with the extreme value of the objective function, on cardamone vertices N×(k-1)+1 objective function zero when calculating the objective function take into account the previously generated codes, wherein the set of pre-allowed transitions in the lattice States, and edges only connect vertices corresponding to the allowed transitions, the source code form randomly, at each level of the tops of the N×(k-1)+1 arbitrarily choose only one initial state, of all the alternative paths to the computed value of the objective function allocate only one alternative path with an extreme value of the objective function at the level of the N×k, and after the formation of the K codes calculate for them the additional function of autocorrelation and choose 2≤M≤K codes with a maximum value of the ratio of the amplitude of the Central peak of the autocorrelation function module and a maximum amplitude of the side peak of the autocorrelation function and the minimum duration of the plot of the autocorrelation function between the point of maximum of the Central peak and the point at which the autocorrelation function for the first time vanishes.

2. The method according to claim 1, characterized in that the allowed transitions in the lattice conditions set in accordance with the selected modulation type of the signal.

3. The method according to claim 1, characterized in that N -an even number.

4. The method according to claim 1, characterized in that the target function is selected when the condition of equality to zero of the value of mutual skal is different compositions between the signals generated ensemble.

5. The method according to claim 2, characterized in that the quality of signal parameters select the phase, amplitude, and frequency.



 

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