RU2634233C1 - Method of generating pseudo-random binary sequence - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method characterized by using a combinatorial device based on an n-bit electronic wheel (EW) - binary oscillator from a shift register (SR) and an adder by module two (Am2) covered by controlled feedbacks (FB), for each of which its own, different from other modes, chain of codes is generated, a pseudo-random binary sequence (PRBS) of the maximum possible length for the given generator without macro-repeaters is obtained, for which a composite PRBS is generated - a composite chain of codes from the corresponding private PRBS - private chains of codes generated alternately in each of the possible modes of the generator operation.

EFFECT: constructing the pseudo-random binary sequence generators with a large code cycle.

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Description

The invention relates to the field of computer science and computer technology and can be used to build pseudo-random binary sequence generators (GPSPS) with a large code cycle.

A known method of storing and using information described in the invention "Storage device" (see patent for invention No. 1805500, IPC G11C 19/00, 04/06/1990), characterized by the use of a combinatorial device based on an n-bit binary generator from a shear register (CP) and adder modulo two (Cm2), covered by controlled feedbacks (OS), each version of which (BOC) generates its own, different from other options, a chain of codes.

The closest in technical essence to the claimed invention is the method described in the brochure [1] - B.I. Kryzhanovsky. "Electronic Wheel", M .: "Knowledge", "Radioelectronics and Communication", No. 5, 1991, fig. 6, p. 18-20], characterized by the use of a combinatorial device based on an n-bit electronic wheel (EC) - a binary generator of CP and Sm2, covered by controlled OS, providing generation at different OSI and at the same time when shifting information left or right and in case of even or odd summation - in the corresponding different modes, for each of which generate their own, different from other modes, code chain (in the prototype - a packet), and to obtain a generation consisting of several chains, upon completion of the gene The operations of each chain switch the operating mode of the generator.

The disadvantage of this method is that the moment of switching modes (from the current to the next) is determined by counting the number of synchronization (ST) generation equal to 2 ⁿ and corresponding to the longest chain of codes (one cycle or one packet) for non-degenerate generation. Meanwhile, for many modes, degenerate generation takes place with a shorter code chain, as a result of which the last part of the code chain repeats at the last synchro-clocks, which reduces the quality of the generated PSDP as a whole. A high-quality PSDP (including a composite one) should have the longest possible chain of codes of one cycle and without their macro repeats, i.e. when for any part of the codes more than n inside one cycle its first half is not equal to the second.

Another disadvantage of the prototype is that it set the task of obtaining multi-packet generation for test sets of technical diagnostics or control commands, etc. (in this case, an increase in the generation length is a negative criterion), but the task was not to obtain the maximum length PSDP on a given n-bit generator without macro repeats, which is important for use in problems with random processes, gaming, etc.

The technical result of the method is to obtain on an n-bit binary generator in the form of an EC as long as possible PSDP without macro repeats by compiling it from code chains obtained in all possible modes of operation of this generator.

The indicated technical result is achieved in that a method for generating a pseudo-random binary sequence, characterized by the use of a combinatorial device based on an n-bit electronic wheel (EC) - a binary generator from a shift register (CP) and an adder modulo two (Cm2), covered by controlled feedback (OS), which provides generation from any initial state for various OS variants (OSI) and at the same time when the information is shifted left or right and with even or odd summation - in corresponding to different modes, for each of which generate their own, different from other modes, code chain, and to obtain generation consisting of several chains, at the end of each chain generation, the generator operation mode is switched, differs in that they receive a pseudorandom binary sequence (PSDP) the maximum possible length for this generator without macro repeats, for which they generate a composite PSDP - a composite chain of codes from the corresponding private PSDP - private chains of codes generated by once in each of the possible modes of operation of this generator, while the moment of switching modes from the current to the next is determined for each private code chain at the first code repeat of the corresponding chain, and the repeated codes are not included in the composite code chain, the process of generating one cycle of the PSDP is completed by generating the corresponding private code chain in the last of the possible modes of operation of the generator.

In FIG. 1, 2, 3 and 4, respectively, to explain the method, a block diagram of a 3-bit generator based on EC and graphs of the code chains generated by it for BOC = 1.3 pp, lion, odd, ref are presented. zero state, for BOC = 1.3 pp, right., odd ref. the state is zero and for BOC = 3 r, lion, even, ref. state is zero. The first two are not degenerate, because all possible codes are present, and the third is degenerate, because codes 010 and 101 are missing.

In FIG. 1 shows CP 1, managed switch 2 (Cm 2) 3, output 4 of generated codes, OS 5, input 6 for setting the initial state and input 7 for managing the switch. All elements of wide application.

The method is as follows.

For simplicity and clarity of explanation, we will operate with a small value of n. Let in accordance with FIG. 1, a 3-bit generator based on EC [1] is used - a binary generator from a shift register (CP) 1 and an adder modulo two (cm2) 3, covered by controlled feedback (OS) 5, which provides generation for various versions of OS 5 (OSI) ) and at the same time when the information is shifted to the left (lion in Fig. 1) or to the right and even (conditionally constant log. 1 at the additional input (Sm2) 3) or odd (conditionally log. 1 only at the 1st step at the additional input ( Cm2) 3) summation - in the corresponding different modes, for each of which they generate their own, about different from other modes, a chain of codes. Moreover, to obtain generation consisting of several chains, upon completion of generation of each chain, the generator operation mode is switched (using the controlled switch 2). In this case, a pseudo-random binary sequence (PSDP) of the maximum possible length for this generator without macro repeats is obtained, for which a composite PSDP is generated - a composite chain of codes from the corresponding private PSDP - private code chains (Figs. 2, 3, 4), generated alternately in each of possible modes of operation of this generator (by automatically switching the switch 2 through input 7 from the control device is not shown in Fig. 1 due to the lack of principle in the framework of this application), while the moment is switched The modes from the current to the next are determined for each private code chain during the first repetition of the first significant - non-zero code of the corresponding chain, and the repeated code is not included in the composite code chain. The process of generating one cycle of the PSDP ends with the generation of the corresponding private code chain in the last of the possible operating modes of the generator.

Let, for example, the sequence of generation modes be carried out in the order of the generated code chains shown in FIG. 2, 3, 4. Then, when the generation of the first of these chains is completed (Fig. 2), after code 100, output 4 repeats the meaningful non-zero code 001, which is determined for this code chain (for example, by the method of elementary comparison), exclude this code from the composite chain (for example, erase in CP 1) and switch the generator to the next mode of operation, generating the corresponding code chain (Fig. 3), then - similarly - (Fig. 4), etc., getting the composite code chain using all 32 = 4 (2 ⁿ⁾ possible lasing given elementary n eratora.

It is obvious that the PSDP generators with a slightly higher capacity are of practical interest. Let, for example, n = 16. Then the number of different options for OSI will be 2 ⁿ = 65536, and in total the various modes of operation of such a generator based on EC will be: 4 (65536) = 262144. One of these operating modes of the generator with BOC = 16, 12, 9, and 7 bits, implemented by Hewlett-Packard in its signature analyzer HP 5004A, generates in one cycle a non-degenerate code chain of 65,536 different (not a single repeat!) 16-bit codes. In 262143 other operating modes of this generator, other non-degenerate code chains of the same long length are also generated, as well as degenerate code chains of a shorter length. According to [1], the placement of codes in each of the code chains is different from all others. Therefore, a composite code chain within one cycle does not have macro repeats. Let us explain this for the same 16-bit generator, all the generated chains of which at the conditional micro level consist of the same 16-bit codes - letters of the corresponding alphabet, and each generated chain has a unique text composed of the same letters. Now, if we analyze the entire compound chain (conditionally, the macro level), then its two largest parts will be the two halves. They do not match, because consist of different unequal code chains. Divide the psitolam each half and get mismatched quarters for the same reason. Etc. to the very micro level. Conventionally, we can say about such a compound chain that it does not have macro repeats, which is important for PSDP.

There are two options to increase the length of the PSDP.

The first possibility is associated with the use in the composite code chain of additional private code chains obtained on the generator when writing to it through input 6 (Fig. 1) a non-zero initial state before each generation of each private code chain. The number of possible initial states of the generator is equal to 2 ⁿ , and in total various code chains, taking into account the additions made, will be: 4 (2 ²ⁿ ).

For a 3-bit generator, the total number of private code chains will be: 4 (2 ²ⁿ ) = 256. Accordingly, the length of the PSDP will increase.

The second possibility of increasing the length of the PSDP is associated with variations of the composite code chain by permuting private code chains in it, i.e. by correspondingly changing the order of the generator operating modes. For a 3-bit generator considered as an example, instead of the above sequence of code chains in figures 2-3-4- ..., for example, change the sequence of code chains in figures 3-2-4, etc. As you know, the number of possible permutations obeys the factorial (!) Law. Even for a 3-bit generator, this is a huge number - the factorial of the number of all private code chains: 256! For generators with a higher bit depth, the number of variants of various composite code chains becomes astronomical, and the length of the PSDP becomes quasi-infinite.

Claims (3)

1. A method for generating a pseudo-random binary sequence, characterized by the use of a combinatorial device based on an n-bit electronic wheel (EC) - a binary generator from a shift register (CP) and an adder modulo two (Cm2), covered by controlled feedbacks (OS), which provides generation from any initial state for various OS variants (OSI) and simultaneously for information shifts left or right and for odd or even summation - in the corresponding different modes, for each of the cats They generate their own, different from other modes, code chain, and to obtain generation consisting of several chains, at the end of each chain generation, the generator operating mode is switched, characterized in that they receive a pseudorandom binary sequence (PSDP) of the maximum possible length for this generator without macro-repeats, for which they generate a composite PSDP - a composite chain of codes from the corresponding private PSDP - private chains of codes generated alternately in each of the possible operating modes of the generator, while the moment of switching modes from the current to the next is determined for each private code chain at the first code replay of the corresponding chain, and the repeated codes are not included in the composite code chain, the process of generating one PSDP cycle is completed by the generation of the corresponding private code chain in the last of the possible operating modes of the generator. 2. The method according to p. 1, characterized in that the PSDP is extended by generating additional private code chains for all possible codes of the initial state of the generator and including these private chains in the composite code chain. 3. The method according to p. 1, characterized in that the PSDP is lengthened by generation and inclusion in it of all the different composite code chains obtained by rearranging the private code chains in them, and changing the order of the corresponding generator operating modes.

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