SU748394A1 - N-digit generator of pseudorandom binary trains - Google Patents

Description

one

The invention relates to the field of computer technology and can be used as a source of random sequences of symbols required for statistical modeling of physical processes and the synthesis of probabilistic automata, as well as sensors; random test signals during the control of logic circuits and as

sensor codes of given weight for MJainHHHdJTo synthesis of co-controlled

tests ..

A device for generating pseudo-random numbers is known, which contains shift registers with modulo-two adders in a feedback circuit. With the help of this arrangement, it is impossible to obtain random juicy sequences with a given set.

By the likelihood of ij., a device is also known that produces random signals with a predetermined probability. The device contains a sensor of random pulses connected to the input of the shift register, a clock generator

pulses, a counter whose outputs are connected to the inputs of the decoder connected by the output to the input of the dial pad connected to the switch matched circuits. The disadvantage of this device is the large hardware costs and the impossibility of promptly changing the probabilities of occurrence of output single signals 2.

The closest technical solution to this invention is a pseudo-random binary sequence generator containing a sensor of uniformly distributed pseudo-random numbers, a code register whose bits are CBJtaaHbi with corresponding sensor bits of uniformly distributed pseudo-random numbers; the groups of OR and AND circuits, through which the bits of the register of the code are connected with each other, the circuit for forming the weight of the code h. The known device has a limited ability to change the probabilities of occurrence of single signals at its Outputs. It is possible to obtain probabilities only from a number of values: A;, ..; jTll j. I. At the same time, many values of the probability | Tv of the output signals are not represented accurately enough. In order to increase the accuracy of the task (in particular, a pseudo-random binary sequence generator containing a code register whose inputs are connected to the sensor outputs of uniformly distributed pseudorandom numbers, a pulse stream sensor is entered and in each bit five elements AND and element OR, output which is connected to the input of the Post-discharge code register, the first input of the OR element is connected to the output of the first AND element, the first input of which is connected to the output of the register of its own discharge code and to the first inputs of the second And the third elements And, the second inputs of which are combined with the first inputs of the fourth and fifth elements And are connected to the outputs of the fourth and fifth elements And the previous discharge, and the outlets of the second and third elements And are connected to the second inputs of the fourth and fifth elements AND, respectively, of the first element, AND, and the element OR, respectively, the outputs of the sensors KJ9 of the pulse fluxes are connected to the second inputs of the second and third elements AND of the first bit, respectively. The drawing shows a functional diagram of the generator .., The generator consists of a n-bit regaster of code 1, consisting of flip-flops 2. A single output of flip-flop 2 in the i-th bit is connected to the input of the AND 3 element, the output of which is Through the OR 4 element, the element AND 5, the element OR 6 is connected to the information input 7 of the 2 B trigger (I +1) -th bit and to the same input of the AND 8 element also in the (i + 1) -th bit the sensor outputs of evenly distributed pseudo-random numbers 9 are connected in each time | p de with inverse input of the element And 8, as well as with the input of the element And 3 NS one an element of the AND 1O element, the second input of which is connected to the clock signal 11, and the output of the element 10 is connected to the clock input 12 of the trigger 2. The output of the element 8 is connected to the input of the element OR 4. The output of the element 13 in the tth digit is connected with the single input of the element E 14 and with one input of the element I 13 in the (r +1) th unit. The second input of the AND 13 element is connected to the inverse output of the AND 14 element and to the inverse input of the OR element 6. The inverse input of the AND 14 element is connected to the output of the OR 4 element, And the 15th output of the i -th element is connected to one input of the AND 16 element and with one input element AND 15 in (t +1) -th discharge de. The second input of the AND 15 element is connected to the I1ters output of the AND 16 element and to the second input of the AND 5 element. The second input of the AND 16 element is connected to the output of the OR 4 element. In the first discharge of the generator, one input of the AND 14 element is connected to the output 17 of the pulse flow sensor 18, and one input of the AND element 16 is connected to the output 19 of the pulse-flux sensor 18. Sensor 9 generates a pseudo-random sequence of evenly distributed zeros and ones, which is used to control the shift of the code in register 1. Preliminarily, the code 1 is entered into register 1 Adequate weight, In the event that the blocks of inputs 15 have zero signals, the process of forming code combinations in. Register 1 occurs as follows. In those bits of the register of code 1, to which the unit states of the bits of the sensor 9 correspond, will be the prohibitive signal from the corresponding outputs of the sensor 9 and the elements 10.. Therefore, the clock signals will not pass to the inputs 12 of the flip-flops 2 in the corresponding bits of the register 1 and these flip-flops 2 retain their state. In those bits of register 1, which correspond to zero states of bits of sensor 9, the signals from the trigger codes of trigger 2 pass through the elements AND 3, OR 4, AND 5, OR 6 and either go to the next register bit 1 (zero in cooTBeTcTBl kschsem sensor bit 9), or pass through the element And 8 further in register 1 (one in the corresponding bit of the sensor 9). Thus, during the shift, the code bits jump over triggers 2, marked by units in the corresponding bits of the sensor 9. Mark the triggers that the qzT remains in its previous state. Since the location of the units and: zeros in the bits of the sensor 9 in each clock cycle varies randomly, as the mixing of zeros and units in register 1 will occur in a random order. Due to the fact that the weight of the code in register 1 remains unchanged | equal to, the mathematical expectation of the occurrence of a unit in a binary sequence at the beginning of any bit of register 1 will be equal to where P is the number of bits of register 1. To obtain the probability value of the output signal equal to P, provided that during which K +1 units will be circulated in register 1, to the time interval during which the unit buset, units, was equal to the value of cr —fp xi / hf; the value of l is determined by the location of the specified probability value P between mi - and, sensor 18 produces two pulse sequences with a period T shifted relative to each other by AT q; j - T. At the same time, the value of the period T must be a short value of the period of clock pulses of the shift; code in register 1. One of the pulse sequences is output via bus 17, and the second delay is dT relative to the first, bus 19. When an impulse appears on bus 17, the number of units in register 1 increases on the bottom, -and pulse on bus 19, the number of units in register 1 decreases by one. An additional unit is written to one of the bits of register 1, in which zero must be written in a given clock cycle. The exclusion of an additional unit occurs due to blocking the transfer of a unit from one of the bits of register 1. For example, at output 17 of block 18, a pulse was required. If, at the same time, at the inverse input of the element AND 14 of the first discharge a permitting signal, then; at the inverse output of AND 14, a zero signal appears, closing the AND 13 element and prohibiting the passage of output pulse 17 further. Thus, with the elements And 14 and And 13, the first zero is detected at the outputs of the elements OR 4. Through the element OR b, the pulse of output 17 gets into the corresponding register register 1, the trigger 2 is set to one, which is allowed to write to the zero signal of the corresponding sensor bit 9. If a pulse appears at the output 19 of the sensor 18 and at the input of the element C 16 t.-ro bit there is an enable signal, then at the inverse of the code of the AND 16 element there appears a zero signal that closes the AND 15 element and prohibits the passage of a pulse from exit 19 dalsh . Thus, the elements 15 and 16 detect the first unit at the outputs of the element OR 4. The zero signal from the output of the element 16 closes the element 5 and prohibits the passage of a single signal from the output of the trigger 2 bit; unmarked by sensor unit 9, Continue further per gist, which is equivalent to transmitting a zero signal. This generator allows you to significantly reduce the error in the representation of a given probability value of the symbols of the pseudo-random sequence formed. Adjusting the sensor 18 so that the value of dT can be changed with discreteness — you can get the specified probability value with a maximum error not exceeding. 2PGT) This allows, without increasing the number of bits of the register of the generator P, to get the specified value of probability from one; -discharge pseudo-random binary sequence generator, containing a code register, the inputs of which are connected to the sensor outputs of evenly distributed pseudo numbers. characterized in that, in order to increase the accuracy of setting the probability, the generator contains a sensor of streams of pulses and, in each discharge, five AND elements and an OR element, the output of which is connected to the input of a subsequent discharge code register, is connected to the output of the OR element. The first element And, the first input of which is connected to the output of the register code of its bit and with the first inputs of the second and third elements And, the second inputs of which are combined with the first inputs of the fourth and fifth elements And, and connected to the outputs of the fourth On the other hand, the AND elements of the previous bit, respectively, and the outputs of the second and third elements AND are connected to the second inputs of the fourth and fifth elements AND, respectively, and the first element AND and the OR element, respectively, the outputs of the sensor of the streams of pulses. the first bit, respectively.

Sources of information taken into account in the examination

 1, USSR Copyright Certificate J 428373, class, q 06 F 1/02, 1974.

2. USSR Author's Certificate No. 440777, cd, N OZ K 3/82, 1974.

3. USSR author's certificate for application number 2447623/24,

Q.Q06F 1/02, 01/27/77 (prototype).

Claims (1)

(Claim B | - a bit generator of pseudorandom binary sequences containing a code register, the inputs of which are connected to the outputs of the sensor of uniformly distributed pseudorandom numbers, characterized in that, in order to increase the accuracy of setting the probability, the generator contains a pulse flux sensor and in each discharge five AND elements and an OR element the output of which is connected to the input of the subsequent code register register, the first input of the OR element is connected to the output of the first AND element, the first input of which is connected to the output of the code register its discharge and with the first inputs of the second and third elements And, the second inputs of which are combined with the first inputs of the fourth and fifth elements And and are connected to the outputs of the fourth and fifth elements And of the previous discharge, respectively, and the outputs of the second th third elements And are connected to the second inputs of the fourth and the fifth element And, respectively, and the first element And and the element OR, respectively, the outputs of the pulse flow sensor are connected to the second inputs of the second and third elements And the first discharge, respectively.