RU2700657C1 - Method of transmitting information in a communication system with noise-like signals - Google Patents

Abstract

FIELD: data processing.SUBSTANCE: invention relates to transmission of digital information and can be used for use in digital communication systems with noise-like signals (NLS). In the method of transmitting information in a communication system with NLS, multiple cyclic time shift (CTS) is introduced into the resulting pseudorandom sequence (PRS) by parallel and independently implemented injection of the CTS into each initial PRS with subsequent multiplication of the obtained PRSes.EFFECT: possibility of paralleling the encoding operation and simultaneous determination of all bits of the received message fragment during decoding.1 cl, 1 dwg

Description

The invention relates to the field of transmission of digital information and is intended for use in transceivers of communication systems.

In telecommunication tasks, in some cases, it is preferable to transmit digital information using noise-like signals (SHPS) (see [1], p. 3); as a rule, tonal signals are used as such signals, the phase manipulation of which is carried out by m-sequences (see [1], section 3.3. p. 49). In the general case, classical pseudorandom sequences (PSP) of a wide class can be used as sequences according to the laws of which the phases of tonal signals are manipulated, therefore, the term “PSP” appears instead of the term “m-sequence”.

The alphabet of transmitted messages, as a rule, contains N _c >> 1 characters. When encoding each transmitted symbol of the corresponding PSP, the communication modem contains a significant number (namely, N _c ) of correlators in each spatial and Doppler reception channels. Moreover, the implementation of the modem is relatively complicated. In this regard, in [2], a variant of the encoding method was proposed, which provides for the operation of generating a single m-sequence, converting a transmitted symbol (for example, C _υ ) into a cyclic time shift (CVC) by υ quanta, each of which is equal to the correlation interval of the SRP, and an introduction to this SRP of the indicated CVS. The decoding device with this encoding method, in addition to [2], is described, for example, in [3]. The advantage of this encoding method is the presence of only one PSP, potentially providing the ability to transmit each of all N _c characters in the alphabet; in this case, the modem in each of the reception channels contains only one correlator; the implementation of such a decoder is relatively simple.

The disadvantage of this analogue is as follows. In order for one SRP to provide the possibility of transmitting each of all N _c characters of the alphabet, it is necessary that its period N _m (expressed in units of time equal to the correlation interval of the SRP) be equal to (or exceed) N _c . The period of any classical PSP T _{with is} directly proportional to its duration, i.e. the product T _c = N _m ⋅τ, where N _m is the number of pulses constituting the SRP (terminology according to [1], Section 3.3), τ is the duration of each of these pulses, and τ≥ΔF ^-1 , where ΔF is the width of the working frequency band communication systems. However, the data transfer rate is inversely proportional to the specified product. The number of bits per one transmitted symbol is log ₂ N _c , and the transmission time of one symbol is proportional to the value of N _c . As a result, as the parameter N _m - = N _c increases, the transmission rate provided by the analog decreases as (log ₂ N _c ) / N _c .

The closest in technical essence to the claimed object is the "Method of transmitting information in a communication system with noise-like signals" according to the patent of the Russian Federation No. 2635552 [4] (prototype). The prototype includes the following operations:

on the transmitting side:

бит и по k дополнительных бит;- divide the stream of transmitted data into blocks containing

bit and k additional bits;

бит соответствующего передаваемого блока в соответствии с выбранным методом кодирования;- form a predetermined memory bandwidth with a DAC defined by a combination of

a bit of the corresponding transmitted block in accordance with the selected encoding method;

- implement code modulation (CM), determined by a combination of k additional bits of the corresponding transmitted block in accordance with the selected encoding method;

- form an ALS sequence by phase manipulation of a high-frequency tone signal;

- transmit the generated sequence of SHPS,

moreover, the input sequences of the data to be transmitted are the input sequences of the data to be divided, and the operation of forming the SRP with the DAC is performed on the results of the operation of the separation of the stream of transmitted data,

on the receiving side:

- convert the received signals into electrical;

- determine the maximum correlation of the received signal with the SHPS formed by phase modulation according to the law of a predetermined bandwidth with zero CVS, for each q _k- th (with q _k = 1 ... Q, with Q = 2 ^k ) alternative to CM;

- determine the combination of k additional bits of the given given data block based on the results of determining the maximum correlation of the received signal with the BSS for each q _kth alternative to the CM;

- determine the value of the DAC in relation to the alternative CM, which corresponds to the specified combination of k additional bits;

бит принятого блока на основании указанного результата определения ЦВС;- determine the combination

the bit of the received block based on the specified result of the DAC;

бит принятого блока по указанным результатам определения его

бит и k дополнительных бит.- form an aggregate

bit of the received block according to the specified results of determining it

bit and k extra bits.

and on the transmitting side:

- KM operation is performed on the results of the formation of the SRP with the DAC;

- the phase-shift operation of the high-frequency tone signal is performed on the results of the KM operation.

бит).The prototype provides an increase in the transmission rate due to the fact that in it on the interval of the same duration of the memory bandwidth, the information DAC is inserted into the transmitted signal (in the BPS) almost twice (the second time in the form of a CM operation). The disadvantage of the prototype is the need (compulsion) to perform two operations of the introduction of the centralized circulation system without fail sequentially. Those. first, the SRP is formed with the DAC, and then this result is subjected to KM operation. The same applies to the totality of a number of operations performed on the receiving side (at first k additional bits are determined (as in the terminology of the prototype description), and then

bit).

бит. При таком развитии прототипа необходимо все операции КМ выполнять последовательно, чем указанный выше недостаток прототипа (невозможности распараллеливания операций введения ЦВС в ПСП при передаче и операций определения

и k бит при приеме) дополнительно усугубляется.It should be noted that the obvious development of the prototype is the multiple (more than twofold) introduction of DAC on the interval of the same DSP duration, which ensures an increase in the transmission speed (the issue of limiting the number of DAC introduced on the interval of the same DSP duration is beyond the scope of this descriptions). In this case, sequentially (and iteratively), the result of the KM operation is in turn additionally subjected to another KM operation, etc. In this case, the amount of information introduced by the SHPS (and transferred by it) with the increase in the number of CM iterations increases. Further, it is precisely such a transmission method that is equivalent to the method described in the description of the patent of the Russian Federation No. 2635552 that is considered as a prototype, and we believe that at each iteration of the CM information with the volume of

bit. With such a development of the prototype, it is necessary to perform all KM operations sequentially than the aforementioned disadvantage of the prototype (the impossibility of parallelizing the operations of introducing a DAC into the SRP during transmission and determination operations

and k bits upon reception) is further exacerbated.

The aim of the proposed method is to eliminate this drawback of the prototype, namely, providing the possibility of the simultaneous implementation of all phases (steps) of the introduction of the DAC in the SRP (or actually in the transmitted signal) during transmission and simultaneous determination of the totality of all bits of the message fragment during reception, while parallelization of significant parts is provided sets of encoding and decoding operations.

The goal is achieved by the fact that in a method of transmitting information in a communication system with a ShPS, which consists in the fact that

on the transmitting side

бит каждый;- divide the stream of transmitted data into n≥2 blocks containing

a bit each;

бит условно первого передаваемого блока в соответствии с выбранным методом кодирования;- form n predetermined SRP, and conditionally the first of these SRP is formed with a DAC defined by a combination of

bit conditionally first transmitted block in accordance with the selected encoding method;

- all formed PSP are multiplied;

- form a sequence of SHPS by phase manipulation of the high-frequency tonal signal with the results of multiplying the SRP;

- transmit the generated sequence of SHPS,

moreover, the input sequence of the data to be transmitted is the input data of the splitting operation of the stream to be transmitted, and the operation of forming the SRP with the DAC is carried out taking into account the results of the operation of splitting the stream of transmitted data,

on the receiving side

- convert the received signals into electrical;

- calculate the correlation of the received signal with Q≥2 reference functions,

- determine the combination of bits of the received message fragment, enter the following operations

upon transfer

бит соответственно условно второго, третьего и всех последующих передаваемых блоков в соответствии с выбранным методом кодирования;- the formation of the conditionally second, third and all subsequent SRPs is carried out with a DAC determined by combinations of

a bit, respectively, conditionally of the second, third and all subsequent transmitted blocks in accordance with the selected encoding method;

upon admission

- carry out the determination of the number of the support function, the correlation of the received signal with which is maximum;

- the combination of bits of the received message fragment is determined by the indicated number of that reference function with which the correlation of the received signal is maximum.

A flowchart illustrating the combination of operations of the proposed method is shown in FIG. 1, more marked:

бит каждый;- 1 - dividing the data stream into n≥2 blocks containing

a bit each;

- 2 - the formation of n memory bandwidth with DAC;

- 3 - multiplication of PSP;

- 4 - phase manipulation;

- 5 - transmission of PShS;

- 6 - conversion of received signals into electrical ones;

- 7.1 ... 7.Q - calculation of correlations of the received signal with Q≥2 reference functions;

- 8 - determination of the number of that support function, the correlation with which the received signal is maximum;

- 9 - determination of the combination of bits of the received message fragment.

All operations of the proposed method, which also appear in the prototype (i.e., operations 4-6 and 9), can be implemented completely similarly to the corresponding operations of the prototype.

бит каждый, реализуется, например, следующим образом. Осуществляется запоминание фрагмента потока, содержащего

бит подлежащей передаче информации. При указанном запоминании этот блок записывается в оперативную память емкостью

бит (здесь и далее упоминаются компоненты цифровых аппаратно-программных средств, реализующих заявляемый способ). Управление записью/чтением передаваемой информации осуществляется программными средствами. Далее запоминается следующий фрагмент из

бит подлежащей передаче информации и указанные функции операции 1 (а также и совокупность всех прочих операций способа) повторяются. Период однократной реализации совокупности указанных функций при выполнении операции 1 и всех прочих операций способа, т.е. период их повторения равен длительности интервала времени Т_с, в течение которого передается один

-битовый фрагмент данных. Последнее относится и ко всем прочим операциям заявляемого способа, которые реализуются последовательно во времени с пренебрежимо малыми задержками, обусловленными конечным быстродействием выполняющих их цифровых аппаратных средств (приведенное здесь утверждение о том, что операции способа реализуются последовательно во времени, в противоречие с поставленной целью не входит; эта цель выше сформулирована как обеспечение возможности одновременной реализации только всех фаз введения ЦВС в ПСП и определения всех бит фрагмента сообщения, но не всех операций способа).Operation 1 of dividing the stream of data to be transmitted into n≥2 blocks containing

each bit is implemented, for example, as follows. The fragment of the stream containing

bit to be transmitted information. With the indicated storage, this block is written into RAM with a capacity of

bit (hereinafter referred to as components of digital hardware and software that implement the inventive method). Writing / reading control of the transmitted information is carried out by software. Next, the next passage from

the bit of the information to be transmitted and the indicated functions of operation 1 (as well as the totality of all other operations of the method) are repeated. The period of a single implementation of the totality of these functions during operation 1 and all other operations of the method, i.e. the repetition period is equal to the duration of the time interval T _s , during which one

bit fragment of data. The latter applies to all other operations of the proposed method, which are implemented sequentially in time with negligible delays due to the finite speed of the digital hardware performing them (the statement here that the operations of the method are implemented sequentially in time, does not contradict the stated goal ; this goal is formulated above as providing the possibility of simultaneous implementation of only all phases of the introduction of DAC in the SRP and the determination of all bits of the message fragment I, but not all operations of the method).

Further, unless otherwise specified, a description is given of the contents of operations 2 ... 9 as applied to the transmission and reception of one stream fragment. Above all fragments of the stream, the entire set of operations of the proposed method is performed, as indicated above, sequentially in time.

бит передаваемого фрагмента сообщения (в условно первую, вторую, … n-ю ПСП вводятся ЦВС, соответствующие первому, второму, … n-му блоку передаваемой информации, содержащему по

бит; здесь нумерация блоков может соответствовать, например, из порядку следования в сообщении). Соответствие между вводимым ЦВС и указанной комбинацией из

бит может быть, например, следующим: выраженный в единицах, равных ΔF^-1 (где ΔF - ширина полосы частот ПСП), ЦВС есть двоичный код, представленный указанной комбинацией из

бит; так, в случае

бит при их комбинации, например, вида 001010 (что в десятичной системе соответствует цифре 10) в ПСП вводится ЦВС величиной 10ΔF^-1. Этот ЦВС может вводиться в ПСП непосредственно в момент ее чтения, при этом чтение начинается с ячейки памяти, номер которой равен указанному двоичному коду.The operation 2 of forming n memory bandwidth with a DAC is carried out taking into account the results of operation 1 by, for example, reading n different memory bandwidths previously stored in it from the memory and introducing into each of them a DAC, the value of which corresponds to a combination of

bit of the transmitted message fragment (in conditionally the first, second, ... n-th SRP, the DACs corresponding to the first, second, ... n-th block of the transmitted information containing

bit; here, the block numbering can correspond, for example, from the order in the message). The correspondence between the input DAC and the specified combination of

a bit can be, for example, the following: expressed in units equal to ΔF ^-1 (where ΔF is the bandwidth of the bandwidth), DAC is a binary code represented by the specified combination of

bit; so in case

a bit when they are combined, for example, of the form 001010 (which corresponds to the figure 10 in the decimal system), a DAC of 10ΔF ^-1 is entered into the SRP. This DAC can be entered into the memory card directly at the time of reading, while reading begins with a memory cell whose number is equal to the specified binary code.

битам блока, в соответствующую этому блоку ПСП, чем и достигается технический эффект, соответствующий цели изобретения.The difference between this operation and a similar operation of the prototype is the admissibility of the simultaneous implementation of the introduction of n CVCs, each of which corresponds to

bits of the block, in the corresponding block of the SRP, which is achieved by the technical effect corresponding to the purpose of the invention.

The operation 3 of multiplying the SRP is carried out on the results of the operation 2 by multiplying all n SRP with the introduced DAC. By this operation we mean vector multiplication, i.e. the formation of an array of temporary reports, each i-th of which is formed as a result of multiplying i-x time samples of all n SRPs.

Operation 4 phase manipulation is carried out on the results of operation 3 and provides for the multiplication of the temporary implementation formed as a result of this operation 3 on a tone carrier frequency. As a result of the operation 4, the next (current) transmitted ShPS is formed (ShPS sequence). Let us explain that one indicated SHPS carries information of one fragment of the transmitted message.

The operation 5 of the transfer of the NPS is implemented on the results of the operation 4 is completely similar to the corresponding operation of the prototype.

Operation 6 converting the received signals into electrical is implemented completely similar to the corresponding operation of the prototype.

, количество таких сочетаний ЦВС и, соответственно, количество опорных функций составляет

. В итоге все опорные функции пронумерованы так, что номер (индекс) q каждой из них равен тому значению бинарного кода фрагмента сообщения, которому соответствует определенное сочетание ЦВС введенных в конкретные (пронумерованные) ПСП (т.е. в первую, вторую и т.д. ПСП введен ЦВС, соответствующий первым, вторым и т.д. блокам из

бит указанного кода - это правило относится также и к выполнению операции 2).Operations 7.1 ... 7.Q calculating the correlations of the received signal with Q≥2 support functions is implemented on the results of operation 6 and is performed, for example, as follows. Preliminarily (that is, before the method is used for its intended purpose), Q support functions are formed, each qth of which (for q = 1 ... Q) is formed, for example, by calculating the product of n SRP (in the same way as the product was calculated n SRP in step 3). In contrast to calculating the product in step 3, the formation of the set of support functions is carried out with all possible combinations of the DACs introduced into them. With the number of possible alternatives (options) of the CVS introduced into each SRP equal to

, the number of such combinations of DAC and, accordingly, the number of support functions is

. As a result, all the support functions are numbered so that the number (index) q of each of them is equal to the value of the binary code of the message fragment, which corresponds to a certain combination of DACs entered into specific (numbered) SRPs (i.e., in the first, second, etc. . SRP introduced CVS corresponding to the first, second, etc. blocks of

bit of the specified code - this rule also applies to the operation 2).

The procedure itself, the calculation of each correlation is implemented as the calculation of the scalar product between the arrays of time samples of the received signal and the reference function (reference: the scalar product is the sum of the products of coinciding time samples in the given case of the received signal and the reference function).

As a result of the execution of the set of operations 7.1 ... 7.Q (when receiving one (each) fragment of the transmitted message), Q numbers are formed, denoted below as S _q (for q = 1 ... Q).

The operation 8 of determining the number of that support function, the correlation with which the received signal is maximum, is performed on the results of operations 7.1 ... 7.Q in accordance with its name, namely, by (for example, pairwise) comparing all S _q numbers, the maximum of them S _{qmax is determined} and its qmax index is fixed;

The operation 9 of determining the combination of bits of the received message fragment is based on the qmax index determined as a result of operation 8. The correspondence between each value of the q index and the code combination of bits of the received fragment is established on the basis of the record of this index, for example, in a binary number system (the binary system option is not only possible, but it seems to be preferable). Those. the qmax number recorded in the binary number system is the combination of bits of the received fragment.

бит передаваемого фрагмента определяются своего рода «одним движением», а не итерационно и последовательно группами, как это было в прототипе.With such a combination of operations 8 and 9, all

the bits of the transmitted fragment are determined by a kind of “one motion”, and not iteratively and sequentially by groups, as was the case in the prototype.

An equivalent embodiment of the proposed method is also possible, in which, instead of operations 7.1 ... 7.Q, involving the calculation of correlations, a set of operations is completed, ending with n operations for calculating the cyclic correlation function.

The inventive method 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 information block (signal or symbol) are known. In principle, it is possible, for example, the option of the transmitter and receiver in a single time system. In this case, the synchronization of the operation of devices that implement signal processing operations at the receiving end is due to the fact that the propagation time of the signal from the transmitter to the receiver is known, and the equipment that implements the receiving operation includes a timer that generates a synchronization signal that controls the implementation of all receiving operations (except for operation 6 converting the received signals into electrical signals) at the time of the start of the arrival of the next fragment of the transmitted stream. Synchronization operations are not included in the structure 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 specific features of the totality of these operations.

All operations of the claimed object, except for operations 5 and partially 6, are implemented by programmable digital signal processing.

The achievement of the technical effect in the inventive method (providing the possibility of parallelizing the operation of introducing the DAC into several MSS and the simultaneous determination of all bits of the received message fragment) was described above in the description of operations 2 (in terms of the possibility of simultaneously implementing the introduction of DAC in several MSS) and 9 (in terms of the possibility simultaneous determination of all bits of a message fragment). It should be noted that these two essentially different technical effects are achieved by a single technical solution, which is based on the implementation of the operation of repeatedly introducing a DAC into the resulting DSP by simultaneously and independently implementing the introduction of DAC into each predetermined (initial) DSP, followed by the multiplication of the obtained DSP.

Literature

1. Varakin L.E. Communication systems with noise-like signals. M .: Radio and communication. 1985.338 s., Ill.

2. Nikolaev R.P., Popov A.R. A method of transmitting information in a communication system with noise-like signals. RF patent No. 2286017.

3. Krantz V.Z., Sechin V.V. Using information symbols to synchronize a communication system with complex signals // Hydroacoustics. Vol. No. 15, 2012. S. 36-41.

4. Golubev A.G. "A method of transmitting information in a communication system with noise-like signals." RF Patent No. Patent No. 2635552.

Claims (15)

The method of transmitting information in a communication system with noise-like signals (SHPS), which consists in the fact that on the transmitting side - divide the stream of transmitted data into n≥2 blocks containing

a bit each; - form n predetermined pseudo-random sequences (PSP), and conditionally the first of these PSP is formed with a cyclic time shift (CVS), determined by a combination of

bit conditionally first transmitted block in accordance with the selected encoding method; - all formed PSP are multiplied; - form a sequence of SHPS by phase manipulation of the high-frequency tonal signal with the results of multiplying the SRP; - transmit the generated sequence of SHPS, moreover, the input sequences of the data to be transmitted are the input sequences of these data, and the operation of forming the SRP with the DAC is carried out taking into account the results of the operation of the separation of the stream of transmitted data on the receiving side - convert the received signals into electrical; - calculate the correlation of the received signal with Q> 2 reference functions, - determine the combination of bits of the received message fragment; characterized in that upon transfer - the formation of the conditionally second, third and all subsequent SRPs is carried out with a DAC determined by combinations of

a bit, respectively, conditionally of the second, third and all subsequent transmitted blocks in accordance with the selected encoding method; upon reception, each qth (for q = l ... Q) of the indicated support functions is formed by calculating the product of n PSP with the corresponding (qth) of all possible combinations of the DAC introduced into them, while the q number of each support function is equal to the corresponding value of the code of the transmitted block; - carry out the determination of the number of the support function, the correlation of the received signal with which is maximum; - the combination of bits of the received message fragment is determined by the indicated number of that reference function, the correlation of the received signal with which is maximum.

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