SU1164897A1 - Adaptive device for decoding ternary codes - Google Patents

Abstract

ADAPTABLE DEVICE FOR DECODING COLLABLE CODES, containing a linear unit at the input, the output of which is connected to the inputs of the first and second filters, which through the corresponding detectors of start codes are connected to the first and second inputs of the starting and coded unit, the output of which is connected to the first input of the decoder unit, the first output of which is connected to the third input of the start-up bdok, and the remaining outputs of the decoding unit are connected to the inputs of the execution units, while the output of the second filter is connected to the input element is NOT, characterized in that, in order to extend the functionality by ensuring the device adapts to changing the nature of errors in the asymmetric communication channel, two elements are entered into the device, for the element And, the trigger and the block for fixing the protective failure, the inputs of which are combined with inputs of execution units, and the output of the latch block of the protective failure is connected to the counting input of the trigger, while the output of the first filter is connected to the first inputs of the first element OR and the first element AND, to (L the second inputs the output of the first element OR and the first element AND are connected to the first inputs of the second and third elements AND, the outputs of which are connected to the inputs of the second OR element, the output of which is connected to the second input of the deco .4. the operating unit, with the direct and in00 outputs of the trigger connected to the second inputs of the second and third elements I.

Description

The invention relates to the field of radio engineering and can be used in digital information transmission systems for detecting and correcting errors such as transformation of symbols into 5 asymmetric communication channels.

The purpose of the invention is the extension. Functional capabilities by allowing the device to adapt to changing the nature of errors in the asymmetric communication channel.

The drawing shows the structures - on the electrical circuit of the adaptive device for decoding ternary codes. 5

The device contains a linear block 1, the first and second filters 2 - and 3, the element NOT 4, the first and second detectors 5 and 6 start codes, the starting block 7, the decoding unit 8, the execution units, the first element OR 10, the first, second and third elements 11, 12 and 13, the second element IL 14, the protective failure-fixing unit 15, trigger 16; decoding unit 8 contains elements of coincidence, memory elements 8, decombinator 19, distributor 20 elements-21 resolution resolutions, six code combinations of 30 have the form: 22I; 2112; 2121; 1221; 1212; 1122 and are at a minimum code distance of 4.

As a decoding unit 8, a decoding unit 35 can be used for. binary code with constant wavelength containing code combinations: OOP; IT; OlOt; 1001; 1010; 1100

The signals from the communication line are fed 40 to the line input of block 1, and then to the inputs of filters 2 and 3. Filter 2 detects the symbols 1, and filter 3 bimvolas 2, so that the binary code 45 is generated at the output of filter 2, and output logic element. NOT 4 - identical to him code K.

Before the working code combination, the starting codes (elements) arrive at the input of the linear block I, which are detected by the detectors of 5.6 starting codes and ensure the triggering of the starting block 7 that starts the distributor 21 of the decoding unit 8.55

In the process of receiving a code combination, the elements of the codes K and K are received at the inputs of the first element OR.

and the first element And 11, which implement the operations of logical, addition or multiplication of code elements, respectively.

Further, the signal from the output of one of the elements 10 or 11 (depending on the state of the trigger 16) goes through the elements AND 12 (13) and the second element OR 14 to the inputs of the matching elements by the decoding unit 8, determining the result of the decoding.

The table reflects the reception and decoding results of one of the code combinations (1122) with different types of errors in the communication channel (erroneous characters are written in brackets).

The considered code has d 4 and, therefore, provides the correction of S 1 and the detection of g 2 errors. .

. Analysis of the table shows that the proposed adaptive device for decoding ternary codes fully realizes the corrective ability of the code, and in some cases even provides error correction. - Indeed, the undistorted code combination is accepted correctly regardless of the state of the trigger 16 (1 and 16 rows of the table). When errors appear in the communication channel such as block 15, the protection failure is automatically switched from trigger 16 to state V (2 is a row of the table), during which the logical addition of code elements K and K will be performed. type errors (3-5 lines of tab - :: faces).

When an error occurs in the communication channel, the type of trigger 16 is automatically transferred by a signal from the output of block 15 to fix the protective failure to the state O (6-row of the table), which implements a logical multiplication of the code elements K and Kj. It also provides for the correction of one or two type 2 errors (7-9 rows of the table).

Obviously, in the general case the number of mismanaged errors will be equal to the number 1 to 2 in the code. 3 tipfi occurrences in the communication channel of a double error of the device type provide a protective failure regardless of the state of the trigger 16 (10 15 rows of the table). In a similar way, it is possible to illustrate the operation of the device for both: scan the Hammin ternary code with, 6, and d, 8 or cyclic ternary code. Thus, the proposed device is able to adapt to the nature of the errors in the communication channel and, i as a consequence, provides for the correction of a large number of errors (up to |. 974 to the number 1 or 2 in the code com binar). As a result, the average probability of correct message reception significantly increases. Considering that the asymmetric communication channels are a sufficiently class of real communication channels, the proposed device can find wide application in the practice of information transmission systems. In this case, it is most advisable to use for transmitting messages the ternary codes for one counting Hamming codes and .se codes.

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Claims (2)

ADAPTIVE DEVICE FOR DECODING TRINITY CODES, containing a linear block at the input, the output of which is connected to the inputs of the first and second filters, the outputs of which are connected to the first and second inputs of the start block, the output of which is connected to the first input of the decoding unit, the first output which is connected to the third input of the start-up unit, and the remaining outputs of the decoding unit are connected to the • inputs of the executive units, while the output of the second filter is connected to the input of the Enta NOT, characterized in that, for the purpose of expansion? functional capabilities by ensuring the adaptation of the device to change the nature of the errors in the asymmetric communication channel, two OR elements, three AND elements, a trigger and a protective failure fixation block are inserted into the device, the inputs of which are combined with the inputs of the executive blocks, and the output of the protective failure fixation block is connected to counting input of the trigger, while the output of the first filter is connected to the first inputs of the first OR element and the first AND element, to the second inputs of which the output of the NOT element is connected, and · the outputs of the first element that OR and the first AND element are connected to the first inputs of the second and third AND elements, respectively, whose outputs are connected to the inputs of the second OR element, the output of which is connected to the second input of the decoding unit, the direct and inverse outputs of the trigger are connected to the second inputs of the second and third elements, respectively AND. SU. „, 1164897 1 1164897 2.