RU2679553C1 - Method of receiving digital information in the conditions of intersymbol interference - Google Patents

Abstract

FIELD: information technology.SUBSTANCE: invention relates to the field of digital information transmission and can be used in receiving devices of synchronous digital communication systems operating, in particular, in conditions of multipath propagation. Method contains the steps of: at each r-th cycle of the time interval for receiving a message (TIRM), the decisive statistics (DS) are calculated ξas a correlation between the signal, observed on the r cycle of the TIRM, and each iset of support functions, on each r cycle of the TIRM with each k separately form the first and second groups of PC ξ, at each r cycle of the TIRM, two groups of sums of ranks are formed; at each r cycle of the TIRM, according to the results of the specified operation of summation of ranks PC, the expected sequences of alternatives to the elementary parcel (EP) are determined, for each i of the hypothesized hypotheses, the sequence of EPs received at each r cycle of the TIRM form realizations accompanying these hypotheses that accompany the components of interference noise (IN), at each r cycle of the TIRM, compensation is made in the realization of the signal observed during this cycle of each of the combinations of the results of the formation of the implementations of the mentioned components calculate the energy of each result of the specified compensation, the decision on the accepted sequence of EPs at each r cycle of the TIRM is taken by comparison between the final PCs generated at this clock cycle using the energy calculation results.EFFECT: technical result is a reduction in computing resources.1 cl, 1 dwg

Description

The invention relates to the field of transmission of digital information and is intended for use in receiving devices of synchronous digital communication systems operating, in particular, in multipath conditions.

One of the significant factors negatively affecting the efficiency (transmission speed and / or decoding error probability) of digital communication systems is the presence of intersymbol interference (ISI), due to multipath propagation and / or transmission of several symbols simultaneously in the same frequency range. This situation is due to the fact that the presence of ISI entails interference due to the temporary overlap of characters transmitted both sequentially and simultaneously (hereinafter, we call all these symbols elementary premises (EP)). These interference are called interference interference (IP).

A known method of reception in digital communication systems "in General" [1, p. 636] in the presence of ISI. The disadvantage of this analogue is the necessary significant computational resources that implement this method of hardware and software, due to the implementation of a plurality of processing channels provided for by this method, each of which is designed to receive an appropriate combination of ES codes (each possible combination of ESs is hereinafter referred to as an alternative to a sequence of ESs).

The specified disadvantage (the necessary significant computing resources that implement the method of hardware and software) is also characteristic of the analogue method described [2].

The closest in technical essence to the claimed method of receiving digital information in the presence of ISI is the object described in [3] (prototype) (almost the full equivalent of this prototype is the analogue described in [4, p. 193, 194],]). The prototype method is based on the so-called Klovsky-Nikolaev algorithm (AKN) (more precisely, the modified Klovsky-Nikolaev algorithm (MACN), which is insignificant in the light of the description of the proposed method). A description of AKN is also given in [5].

To simplify the descriptions (referring to the descriptions of both the prototype and the proposed method) it is further assumed that the form of the impulse response of the channel (IRF) of the multipath propagation h (t) at the receiving end of the communication system is known. In order to ensure its measurement on the transmitting side at r = 0-th cycle of the system, a test pulse is generated and transmitted, the shape of which is known on the receiving side; a similar principle of functioning of a communication system (“a system with a test pulse and prediction”) is described, in particular, in [4, 5]). To simplify the description, the set of operations providing the measurement of the KFM is omitted. A similar situation occurs in the description of the prototype [3], as well as in the sources [4, 5].

The principle of operation of the prototype is as follows (the following is a comparatively detailed description of the prototype due to the fact that the presence of such a description simplifies the description of the proposed method).

The assumption of which of the alternatives to the EP sequence is accepted (transmitted) is called the EP sequence hypothesis. When the set of symbols of the alphabet of transmitted messages is known at the receiving end of the communication system, the form of the signal received or observed at the time interval for receiving the message (IVPS) of the signal by which the entire message is transmitted, with the validity of each specific hypothesis mentioned, is known. Moreover, the shape of each possible sequence of EP is also known. The number of a particular sequence of EPs is denoted by the index i for i = 1 ... I, where I is the total number of possible sequences of alternatives (or, which is the same, sequences of alternatives) of EPs.

Due to the fact that the number of possible alternatives to EP sequences is finite (countable), it is possible to form alternatives to sequences of EP sequences of temporary realizations accompanying IP components that correspond to all hypotheses, which is implemented in the prototype (and almost exactly the same in the claimed method).

Note. In the source of the description of the prototype (and in all other sources that describe the method of administration, which is based on AKN), along with the accompanying component of the IP, the residual component of the IP also appears (explanations of these terms are given in the next paragraph). In the framework of the present description, the residual component of IP is omitted (the rationale for this is given below), which does not exclude its consideration when implementing the proposed method without changing the inventive concept.

Explanations of terminology.

1. The residual component of the PI (or the residual signal of the MSI) is an interference occurring due to temporary overlap with the analyzed EP of those EPs that were transmitted before it; the accompanying component of IP is an interference occurring due to temporary overlap with the analyzed EP of those EPs that were transmitted after it [4, p. 193] (these IP components are further indicated as q _{r ost} (t) and q _{r sopr} (t), respectively). Next, we clarify this definition of the accompanying component of the IP as interference occurring due to temporary overlap with the analyzed EP of those EPs that were transmitted simultaneously with this analyzed EP, and neglect the effects of overlapping from the last of those EPs that were transmitted after it. The meaning and reason for such a clarification is explained below.

2. The entire IVPS is divided into measures, the duration of each of which is equal to the sum of the durations of the electromagnetism τ and the KFM τ _and , and the time interval between the moments of the start of the time-adjacent measures is equal to the duration of the electromagnetism τ. The process (set of operations) of signal processing on the time interval of each rth beat is hereinafter referred to as the rth beat of the communication system or simply the rth beat. This r-th clock is located in the time interval (r-1) τ ... rτ + τ _and (here τ is not only the duration of the ES, but also the period of the following ES in the message). In this case, the beginning of the countdown at the receiving end of the communication system coincides with the moment of arrival of the first (informational) electronic signature. As noted above, by default it is assumed that providing a measurement of the KFM at the r = 0-th clock cycle of the system, a test pulse is transmitted in it.

3. In fact, in the prototype (as well as in the claimed method), there are operations performed not on the components of the IP, but directly on the alternatives of the received sequences of EP. Thus, the terminology used in the technical literature to describe the methods of administration, which are based on AKN, is very arbitrary. In the present description, this convention of terminology is preserved.

The above refinement of the definition of the accompanying component of the IP is due to the fact that the claimed method (in contrast to the well-known analogues based on AKM or IACM) is mainly focused on the situation of transmitting several ES simultaneously in the same frequency band. In this case, the solution to the problem of efficient decoding with respect to MSI generated by the temporary overlapping of EFs transmitted not so much in different time-related IVSP clocks as in the same clock is especially relevant. Moreover, the inventive method remains relevant also in relation to the traditionally considered situation of ISI generated by the imposition of electronic transmissions transmitted in different time-related IVSP clock cycles. For this reason, accounting for the residual component of PI q _{r ost} (t) is also largely lost. In this regard, in the ratio (1) below, the term q _{r ost} (t) (available in a similar formula in the materials describing the prototype) is omitted.

Due to the fact that the prototype, formally speaking, is designed for the situation of transmission (and, accordingly, reception) in each cycle of the communication system of a single electronic drive, the following is a description of the principle of its operation in relation to this situation. At the same time, in order to ensure universalization of the description of the prototype and the proposed method (which is designed to simultaneously transmit K EPs that make up a block or sequence), we refer to the only EP as a sequence of EPs (i.e., as applied to a prototype, we consider a sequence of simultaneously transmitted EPs consisting of K = 1 EP).

The considered components of IP are calculated, for example, as a result of convolution of the sum of each of the transmitted EPs with the KFM. A comprehensive description of the procedure for the formation of the components of IP is given, in particular, in [4].

At each rth beat of the IVPS in the prototype in the implementation of the signal s _r (t) observed on this beat, compensation is made for each of the combinations of the results of the formation of implementations of all the above-mentioned components of the IP, namely, the differences are calculated

moreover, the index i characterizes the number of the hypothesis of EP located in the message after the r-1-st cycle of IVPS. The principle of implementation of the prototype and the proposed method with the relevance of compensation of the components of IP generated by the fragment of the sequence of EP located in the message after the i-th step of the IVPS is explained below (at the end of the present description). The form of the accompanying component of the PI in the i-th alternative to the sequence of EPs taken at the rth beat is determined, for example, as

where S _ir (t) is a possible alternative to the EP transmitted on the rth clock cycle of the communication system (in most situations, this alternative does not depend on the index r, but for the sake of generality, this index is further preserved), ⊗ is the aperiodic calculation operation, or (that the same) linear convolution;

Then, in the prototype, at each r-th step of the IVPS, the estimates of the energy n _{ir of the} implementation of the difference signal δ _ir (t) are calculated for each of the indices i

The value of n _{ir is} used in the prototype as the final PC corresponding to the reception (i.e., tuned to receive) of the i-th alternative to the EP sequence in (or on) the r-th IVPS tact. The decision on the adopted EP sequence in the prototype at each r-th IVPS cycle is made in favor of its alternative (i.e., the alternative to the EP sequence), which corresponds to the index i for PC n _ir (2), which is among all the PCs formed on this cycle minimum, i.e. by finding an estimate of the specified index i of the form

those. finding the index i (for each r), which corresponds to the minimum (for each r), n _ir .

The disadvantage of the prototype (as well as all other analogues, which are based to one degree or another on the so-called method of receiving messages "in general") - the extremely high required computing resources of equipment that implements the reception of digital information - is due to the following. Let each ES carries (contains) q bits of information. Then I = 2 ^q . It should be noted that in order to ensure a high transmission rate, the q value should be very large. So, for example, at q-40, the number of alternatives to the EP sequence (at each step) is I = 2 ⁴⁰ ≈10 ¹² . If, in addition, the duration of each ES is, for example, 1 s, then the prototype requires hardware that performs calculations using the totality of formulas (1) ... (3) ≈10 ¹² times per second (not the number of operations per second, but the number of calculations by the specified formulas per second). Such hardware today (at least, if you do not take into account the unique unique computing stationary systems) does not exist. In this regard, if the prototype (being very effective in terms of such an important criterion as noise immunity) is applied in practice, then, firstly, it is very limited, and secondly, with a smaller value of the parameter q than that considered above, what determines the relatively low speed of information transfer.

The aim of the proposed method is to reduce the computing resources necessary for implementing the reception of digital information (or, which is essentially the same, increasing the speed of information transfer with the same necessary computing resources).

Further, without claiming to be novelty in this part, we believe that (as has been repeatedly noted above) K EPs are transmitted simultaneously, with each of them having a bit depth of p _k . The combination of these K EPs is called a block or sequence. Then, for example, at K = 4 and p _k = 10, the number of alternatives to the EP sequence (at each clock cycle of the communication system) is I = 2 ⁴⁰ ≈10 ¹² , i.e. as many as there were in the above example at p = 40 and K = 1. At the same time, the application of the claimed method in this situation (i.e., for K> 1) allows the modem computing resources necessary for receiving (decoding) the message (in comparison with those indicated in the first line of this page) to be significantly reduced.

This goal is achieved by the fact that in the method of receiving digital information in the conditions of intersymbol interference, in accordance with which

- with respect to each i-th hypothesis of hypothesis, the EP sequences received at each rth beat of the IHPS form the implementations of the accompanying IP components q _{ir sopp} (t) corresponding to these hypotheses;

- at each r-th step, the IWPS carry out compensation in the implementation of the signal s _r (i), observed at this beat, of each of the combinations of the results of the formation of the implementations of the above-mentioned IP components in accordance with relation (1); compensation results are denoted as δ _ir (t);

- calculate the energy of each result of the specified compensation n _ir in accordance with the relation (2);

- the decision on the adopted sequence of EPs at each rth IVPS cycle is made by comparing with each other the final decision statistics (PC) generated on this cycle using the results of calculating energies n _ir ,

moreover

- at each rth beat of the IVPS, PC ξ _{irk is calculated} as the correlation between the signal s _r (t) observed on the rth beat of the IVPS and each i _kth set of support functions, and each support function from the i _kth set coincides with the corresponding (i.e., i-th) alternative of the k-th EP taken at this clock step, where for two simultaneously transmitted on each r-th clock IVPS ES, the parameter k takes values 1 and 2;

- on each rth step, the IVPS for each k separately form the first and second groups PC ξ _irk containing respectively w ₁ and w ₂ > w _{1 of the} indicated PCs, and PC ξ _irk included in the specified first group are w ₁ senior the members of the variational rad, made up of the set PC ξ _irk , and PC ξ _irk included in the indicated second group are w ₂ senior members of the indicated variation series;

- on each rth beat of the IVPS, two groups of rank sums (PC position numbers in the corresponding variational series) are formed, and the sums of the first of these sum groups are formed by summing the ranks of each PC ξ _irk for k = 1 from the indicated first group of these PCs and each PC ξ _irk for k = 2 from the indicated second group of these PCs, and the sums of the second of the indicated groups of sums are formed by summing the ranks of each PC ξ _irk for k = 2 from the indicated first group of these PCs and each PC ξ _irk for k = 1 from the specified second group these PCs;

- on each r-th step of the IVPS, according to the results of the indicated operation of summing up the ranks of the PCs, the expected sequences of alternatives (codes) of EP are determined, moreover, when performing the totality of the above operations of forming realizations q _{ir sop} (t) and δ _ir (t), as well as n _ir as possible sequences of EP alternatives are considered only the indicated putative sequences of EP alternatives.

Hereinafter, a description is given of an example of the implementation of the proposed method in the presence of two transmitters simultaneously transmitted in the block and the formation of two groups PC ξ _irk and two groups of sums of ranks. In the general case, the number of EPs in the block (K) and the groups PC ξ _irk may be more than two (moreover, the number of EPs in the block with the number of groups PC ξ _irk may not coincide). A prerequisite for the applicability of the proposed method is the presence of at least two simultaneously transmitted EPs in the block and the formation of at least two groups PC ξ _irk . In this regard, the description is given in relation to the specified minimum required combination of these parameters. The foregoing applies to the claims.

It is significant that if in the prototype all possible sequences of EPs were considered as hypothesized hypotheses of the sequence of EPs taken at each rth cycle of the IVPS, then in the claimed method only those of the possible sequences of EPs that were determined as a result of sequential execution of a set of operations PC ξ _irk computing, for each k forming the first and second groups of PC ξ _irk, forming sums of the two groups of ranks and proper determination putative sequences (or, equivalently, combining s codes) EP.

A flowchart illustrating the inventive method is shown in FIG. 1, where are indicated:

- 1.1; 1.2 - PC calculations on each r-th beat of the IVPS;

- 2.1 ... 2.4 - formation of PC groups;

- 3.1, 3.2 - the formation of groups of sums of ranks;

- 4 - definition of the alleged combinations of codes of electronic signature;

- 5 - formation of the implementation of the accompanying component of the IP q _{ir sopr} (t) with respect to each possible i-th hypothesis of the sequence of electronic messages received;

- 6 - compensation in the implementation of the signal s _r (t) observed on the rth cycle of the IVPS, of each of the combinations of the results of the formation of implementations of the components of the IP on this tact of the IVPS;

- 7 - determination of the energy estimate of each compensation result at each rth bar of the IVPS;

- 8 - development of a decision on the adopted sequence of EPs at each rth beat of the IVPS.

The operation (set of operations) 1.1 and 1.2 (computing PC on each rth beat of the IVPS; hereinafter, a description of the contents of the operations of the proposed method performed separately on each rth beat of the IVPS) is performed by calculations by the formula

where each i _k th (i = 1 ... I; k = 1, 2) reference function Y _ik (t) in the case of propagation of a transmitted signal in a multipath channel with an impulse response h (t) (as noted above, the form of the channel impulse response h (t) can be considered known) is calculated, for example, as follows

where S _r (t) is the temporal realization of the signal received (observed) at the r-th clock of the TDI, and S _ik (t) is the ES at the transmission point corresponding to the transmission situation of the i-th alternative of the k-th ES ( ith alternative of the transmitted character). Let us once again explain the meaning of the double indexation of the electric field S _ik (t). As noted above, the simultaneous transmission of K EFs is assumed (i.e., the transfer of a block of K EFs, moreover, the particular situation K = 2 is considered in the description). In this case, the index k indicates the number of EPs in the block, and the index i indicates the number of alternatives to this EP.

The set of calculations by formulas (4) and (5) is performed for all possible combinations of values of index i = 1 ... I and index k = 1 and 2. In total, such combinations are generally KI (hereinafter, when mentioning the number of results of each operation of the proposed method refers to the specified number related to one clock cycle implementing this method of communication system).

Operation (set of operations) 2.1 ... 2.4 (formation of PC groups) is performed as follows. For each value of the index k separately (for k = 1, 2), w ₁ PC ξ _irk , which are w ₁ senior members of the variational series composed of all I PCξ _irk , and also w ₂ > w ₁ PCξ _irk , which are w ₂ senior members of the variational series composed of the same I PCξ _irk (in all cases, the indicated components of the set of operations 2.1 ... 2.4 are performed separately for each specific value of the index k). The determination of w _{1 the} senior members of the variational series is made, for example, as follows. Initially, arbitrary w ₁ PCξ irk are _remembered for some value of the index k (the value of the index r is also fixed). These PCs are arranged in increasing order of the _reference levels ξ _irk , i.e. an array of these PCs is used to construct a variation series. In this case, both the values of these PC ξ _irk and their numbers in the variational series (or ranks) and the codes corresponding to each of them (numbers of alternatives i) of the EP are stored. (Recall that the array PC ξ _irk contains I> w _{1 of} these PCs). Further, some w ₁ + 1st PC ξ _irk (an arbitrary PC of an array from I PC and not included in the array of w ₁ originally selected PCs) is compared in terms of level with each member of the indicated variation series. Moreover, if this PC is less than the smallest member of this series, then it is discarded. Otherwise, it is located in the variational series after the largest of the totality of the members of this series smaller than this PC, and PC, which was before this phase of the operation of forming the group of PCs by the level of the smallest in this series, is discarded. The sequence of actions described below is performed until all I PC ξ _{irk have been exhausted} (for fixed values of r and k). As a result, a variational series is formed consisting of w ₁ PC ξ _irk , i.e. memorized, for example, the levels of these PCs, as well as their numbers in the variation series, or the ranks R _kj and the corresponding indices i of alternatives for EP (hereinafter referred to as the parameters listed are the parameters of the corresponding variation series). The combination of rank R _kj and the corresponding index i of the EP alternative indicated in the previous phrase is hereinafter referred to as R _ikj for brevity.

We consider that the rank R _ikj = 1 corresponds to the largest in the variation series in terms of PC, and the rank R _ikj = w _{1 to the} smallest. The index k = 1 or 2 at the rank means that this rank refers to PC ξ _irk with the corresponding index k, and the index j = 1 or 2 characterizes the number of the group PC (the meaning of the term “group” is explained in the next phrase)). The specified data set is referred to as the PC group. This group belongs to the PC array with a specific index k and is formed by w _{1 by the} senior members of the variational series composed of all I PC ξ _irk . The groups PC formed by w ₁ and w _{2 by the} senior members of the variational series composed of I PC ξ _irk are called the first and second groups of PC, respectively. As a result of performing the set of operations 2.1 and 2.3, the first PC groups are formed, characterized by the parameter k = 1 and 2, respectively, and as a result of performing the set of operations 2.2 and 2.4, the second PC groups are formed, also characterized by the parameter k = 1 and 2, respectively.

The operation (set of operations) 3.1 and 3.2 (the formation of groups of sums of ranks) is performed as follows. Each sum of two ranks included in each of the indicated groups (to avoid tautology) is called a component of the group of sums of ranks. The components of the first of the indicated groups of rank sums are formed by summing the ranks of each PC ξ _irk for k = 1 from the indicated first group of these PCs and each PC ξ _irk at k = 2 from the indicated second group of these PCs. The components of the second of the indicated groups of rank sums are formed by summing the ranks of each PC ξ _irk for k = 2 from the indicated first group of these PCs and each PC ξ _irk at k = 1 from the indicated second group of these PCs. Further, the designations of the numbers of EP alternatives at the index k = 1 are specified as i1, and EP alternatives at the index k = 2 are specified as i2. Moreover, the ranks PC ξ _irk for the values of the index k = 1 are denoted by R _i1kj , and the ranks PC ξ _irk for the values of the index k = 2 are _denoted as R _i2kj . The sum of the two indicated ranks is denoted as Σ _{i1 i2} (i.e., the sum of ranks in this situation means a combination of parameters such as the sum of the ranks, as well as a combination of alternative numbers (or, what is the same, a combination of codes) of two EPs in the received block.

As a result of the execution of operations 3.1 and 3.2, two groups of sums of ranks PC are formed, each containing w ₁ w _{2 of} these components, or, in other words, with K = 2, only 2w ₁ w _{2 of} these components are formed.

Operation 4 (determination of the alleged combinations of EP codes) is performed by selecting from the 2w ₁ w _{2 the} above components (sums of ranks) ϒ << 2w ₁ w ₂ components that are the smallest in terms of level. This operation is performed essentially the same as operations 2.1 ... 2.4, with the only difference being that the selection is carried out by the smallest components in terms of level). In this case, all the actions listed above in the description of operations 2.1 ... 2.4 are performed, but when replacing all the results of the comparison operations with the opposite, i.e. in the results of comparisons are not discarded the smallest, in the largest components. As a result of operation 4, an array of ϒ pairs of indices i1, i2 of alternatives to the EP block is formed, which are pairs of indices for the above ϒ least-level components (sums of ranks). The values of the levels of these components themselves are insignificant and do not participate in further processing. Each of these pairs of indices characterizes (unambiguously determines) one of the proposed combinations of ES codes in a block. To ensure the unification of the descriptions of the prototype and the proposed method, hereinafter, the combination of indices i1, i2 is denoted as i-th (i.e., the combination of the i1st alternative k = 1st ES in the block and the i2th alternative k = 2nd ES in the block is called the ith combination of alternatives or sequences or codes of electronic messages in a block or in a message (the latter refers primarily to the case when the message consists of one block).

All other operations of the proposed method are carried out in much the same way as the corresponding operations of the prototype.

Operation 5 (the formation of the implementation of the accompanying component of the IP q _{ir sop} (t) with respect to each possible i-th hypothesis of the EP sequence of the received message) is performed, for example, by calculations using a formula similar to (1a), with the following refinement (in relation to situation K = 2)

where S _i1r (t), S _i2r (t) is, respectively, the implementation of the _i1st alternative k = 1st ES in the block and the implementation of the i2th alternative k = 2nd ES in the block.

Operation 5 and all subsequent operations of the proposed method is performed only on those alternatives to EPs whose indices are determined as a result of step 4 (determining the alleged combinations of ES codes). As a result of operation 5, 2w ₁ w ₂ realizations of the accompanying component of the IP q _{ir sopp} (t) are formed.

Operation 6 (compensation in the implementation of the signal s _r (f) observed on the rth cycle of the IVPS, of each of the combinations of the results of the formation of the implementations of the components of the IP on this IVPS beat) is performed completely analogously to the corresponding operation of the prototype, namely, calculations by the formula (1) ; these calculations are carried out with respect to each implementation of the accompanying PI component q _{ir sopp (t)} , i.e. As a result of its implementation, 2w ₁ w ₂ realizations of the difference δ _ir (t) are formed.

Operation 7 (determination of the energy estimate of each compensation result at each r-th ICT cycle) is performed completely similar to the corresponding operation of the prototype, namely, by calculations according to formula (2); these calculations are performed for each implementation of the difference δ _ir (t), i.e. As a result of its implementation, 2w ₁ w ₂ values of the energy estimate n _ir (t) are formed.

Operation 8 (development of a decision on the adopted sequence of EPs at each rth cycle of the IVPS) is performed completely analogously to the corresponding operation of the prototype, i.e. the decision on the adopted sequence of EPs in the claimed method at each rth cycle of the IVPS is made in favor of its alternative (i.e., an alternative to the sequence of EPs), which corresponds to the index i in the PC assessment of the energy of each compensation result n _ir , which is among all generated on This tact of PC is minimal. This operation (as in the prototype) is described by formula (3).

All operations of the proposed method are implemented by universal programmable microprocessors. It is possible to combine the implementation of several operations of the method in one microprocessor.

The inventive method, like the prototype, is designed for use in a synchronous communication system. In such a system, at the receiving end, the moments of the beginning of arrival of each ES are known. In principle, for example, a variant of the operation of the transmitting and receiving parts of the transmission system in a single time system is possible. Moreover, with regard to the synchronization of the operation of devices that implement signal processing operations at the receiving end, the propagation time of the signal from the transmitter to the receiver is known, and the equipment that implements the reception operations includes a timer that generates (generates) clock signals that control the execution of all receiving operations.

The set of synchronization operations is not included in the composition of the claimed object, since the vast majority of digital (discrete) communication systems are synchronous, and the features of the claimed object are not associated with any specifics of the specified set of operations.

The principle of operation of the proposed method largely coincides with the principle of action of the prototype. The only difference between these objects is that, if in the prototype all possible sequences were considered as supposed EP sequences, then in the claimed method the number of putative EP sequences (due to a set of operations 1 ... 4) is significantly reduced without loss of reception efficiency (noise immunity). The fundamental basis for this reduction (namely, without loss of noise immunity) is the following effect. It is easy to establish that in any pair of PC ξ _irk (this pair includes PCs with different indices k) one of these PCs is practically guaranteed to not exceed in level no more than w ₁ PC ξ _irk for the same value of k, and the second of these PCs does not exceed in level no more than w ₂ PC ξ _irk for the same value of k. When developing the proposed method and its modeling, it was found that, for example, with p _k = 20 and K = 2, the value of w ₁ is 300, aw ₂ -10 ⁴ . Thus, given the fame of which PC ξ _irk (i.e., PC for which particular value of the index k) is among w ₁ senior members of the variational series of 2 ^pk ≈10 ⁶ alternatives of EP, and which among w ₂ senior members of the indicated variation series, the totality of the proposed combinations (sequences of codes) of EP in the block would consist of w ₁ × w _{2 of the} indicated combinations. Due to the fact that the specified information is not known in advance, the selection of the alleged combinations of ES in the block is carried out for all possible (i.e., for two) options for the ranks of the two indicated PCs; and at the same time, the totality of the alleged combinations of EP in the block consists of 2w ₁ × w _{2 of} these combinations.

Possible equivalents of the proposed method. So, when performing a set of operations 2.1 ... 2.4 (formation of PC groups), we can assume that the rank R _ikj = 1 corresponds to the smallest in the variational series in terms of PC, the rank R _ikj = w ₁ - the largest in terms of PC. In this case, operation 4 (determining the alleged combinations of EP codes) is performed by selecting from the 2w ₁ w ₂ components (sums of ranks) ϒ << 2w ₁ w ₂ components that are the largest in level. A variant of the implementation of the proposed method using the comparison of two PCs in each pair is also possible and when determining the proposed combinations of EP codes, consider only w ₁ components corresponding to the highest level of these PCs in combination with W2 components corresponding to the lowest level of these PCs.

The technical effect in the claimed method (reduction necessary for the implementation of the reception of digital information computing resources) is due to the following. For example, with p _k = 20 and K = 2 (or, which is the same when implementing the prototype) with p = 40 and K = 1, the set of operations 5 ... 8 (these operations in the description of the prototype are designated as 2 ... 5, respectively) is performed on 2 ⁴⁰ ≈10 ¹² alternatives to ES, and the same set of operations in the present method is only over 2 × 300 × 10 ⁴ <10 ⁷ alternatives (combinations or sequences or codes) of ES.

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5. Klovsky D. D. Transmission of discrete messages over the air. - M .: Radio and communication. 1982. - 304 p.: Ill.

Claims (12)

The method of receiving digital information in the conditions of intersymbol interference, in accordance with which - with respect to each i-th hypothesis of hypothesis, the sequence of electronic signals received at each r-th clock of the message reception time interval (IVPS) forms the implementations corresponding to these hypotheses of implementation of q _{ir sopr} (t) component of the IP; - at each rth beat, the IHPS carry out compensation in the implementation of the signal s _r (t) observed at this beat of each of the combinations of the results of the formation of implementations of all the above-mentioned PI components in accordance with the ratio δ (t) _ir = s _r (t) -q _{ir sop} (t); - calculate the energy n _{ir of} each result of the specified compensation in accordance with the ratio

- the decision on the adopted sequence of EPs at each rth IVPS cycle is made by comparing among themselves the decisive statistics (PC) generated on this cycle using the results of calculating energies n _ir , characterized in that - at each rth beat of the IVPS, PC ξ _{irk is calculated} as the correlation between the signal s _r (t) observed on the rth beat of the IVPS and each i _kth set of support functions, and each support function from the i _kth set coincides with the corresponding alternative of the k-th EP taken at this beat, where for two simultaneously transmitted on each rth beat IVPS ES the parameter k = 1, 2; - on each rth beat, the IVPS for each k forms the first and second groups PC ξ _irk containing respectively w ₁ and w ₂ > w _{1 of the} indicated PCs, and PC ξ _irk included in the specified first group are w ₁ senior members a variational series made up of the set PC ξ _irk , and PC ξ _irk included in the indicated second group are w ₂ senior members of the indicated variational series; - on each rth beat of the IVPS, two groups of rank sums (PC position numbers in the corresponding variational series) are formed, and the sums of the first of these sum groups are formed by summing the ranks of each PC ξ _irk for k = 1 from the indicated first group of these PCs and each PC ξ _irk for k = 2 from the indicated second group of these PCs, and the sums of the second of the indicated groups of sums are formed by summing the ranks of each PC ξ _irk for k = 2 from the indicated first group of these PCs and each PC ξ _irk for k = 1 from the specified second group these PCs; - on each rth beat of the IVPS, according to the results of the indicated operation of summing the ranks of the PCs, the intended combinations of ES codes are determined, moreover, the combination of the above operations for generating realizations q _{ir sopp} (t) and δ (t) _ir , as well as energies n _{ir, is} performed only as to alleged combinations of ES codes.

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