SU930335A2 - Device for preventing error in data transmitting systems - Google Patents

Description

(54) DEVICE FOR PREVENTION OF ERRORS IN DATA TRANSFER SYSTEMS

one

The invention relates to the transmission of data and is intended for use in the equipment for receiving discrete information in systems with decision feedback.

According to the main author. St. No. a device for preventing errors in data transmission systems is known, which contains a write register, the control input of which is connected to the output of the control unit, the first output of the record register is connected to the information input of the read element, the control input of which is connected to the output of the analyzer the reading is connected to the input of the output block, the first input of the analyzer of the combination of code combinations is combined with the first input of the OR element and connected to the input of the device, the output of the ment read connected to the second OR input of the element, whose output is connected to an input write register, the second input

which is connected to the second input of the match code analyzer.

The disadvantage of this device is the low reliability, which is manifested in the fact that after the i-th transmission of the combination, the transfer of the next combination or (i + l) - the transfer of the previously transferred one is carried out after receiving

10 feedback signal. In this case, a loss (not reception) of the next combination occurs, if it was identical to the previous one (for example, a combination characterizes two objects,

15 which are in the same condition in a single patch).

The purpose of the invention is to increase the reliability of the device.

The goal is achieved

20 in that the device for preventing errors in data transmission systems has introduced a time sensor, the first input of which is connected to the second input of the control unit, and the output to the installation input of the write register. In addition, a code number repeat number selector is entered into the device, the output of which is connected to the second time sensor input. The time sensor allows you to count the time during which the arrival of repetitions of the same code combination is possible and when the repetitions should be selected. After this time, the signal from the time sensor erases the information in the record register, thereby resolving the reception of the next code combination (which in some cases may be identical to the previous combination). . A further reduction in the loss of information is achieved by introducing a code number repeat number selector, which, depending on the number of the combination received, adjusts the time sensor to the appropriate selection time. The drawing shows the functional scheme of the proposed device. The device contains the OR element 1 register 2 records, the analyzer 3 matches the combination of electronic readings, the sensor 5, the control unit 6, the output block 7 and the selector number 8 of the code combinations. Through the OR 1 element, the n-bit code combination is written and rewritten into register 2. Analyzer 3 is intended for bitwise comparison of the previous and subsequent combinations. The read element is intended to issue a message to the output block. Time sensor 5 is designed to count the selection time, which in the particular case will be equal to G.A. "where V (baud) is the modulation rate; E - the maximum number of repetitions of the combination. The control unit 6 is selected from the considerations of the applied feedback and the accelerated rewriting of information in the time interval between two incoming messages. The selector 8 determines the repetition number of the code combination j and sets the selection time on the time sensor 5 - (bj) s. In the particular case where the repeat number is contained in a group of code combination elements, the selector is executed as a decoder, the input of which is connected, to the additional output of the write register. The initial state of register 2 is zero. The device works as follows. The received code combination through the element OR 1 is written bitwise into register 2 of the record, pushes the analyzer 3 and at the same time goes through another input directly to the analyzer 3. from the bits, a permission signal is generated, which arrives at the control inputs of the readout element and the control unit 6 and permits the translation of the received code combination from register 2 to the output block 7 of messages and record this codeword again write register 2 through an OR 1, wherein the process is carried out rapidly in order to zakonchits the time of initiation of the next combination. At the same time, the control unit 6 generates a signal, which turns on the time sensor 5, the selection time t starts counting down. The subsequent code combination received is written to register 2 of the record, pushing the previous information to analyzer 3 matches, and simultaneously arriving through another input directly to analyzer 3 matches. In the case of coincidence of the elements of a code combination in all bits of the signal. The output resolution of analyzer 3 is absent and the code combination from register 2 is not read. Thus, if as a result of the analysis of two code combinations, all the bits are the same, then the code combination is not output to the output block 7, if, at least in one of the code combination bits, the elements

do not match, then the accepted combination is output to output block 7 and is overwritten in register 2 of the record. At the end of the selection time t, time sensor 5 outputs a signal that sets register 2 to the initial (zero) state. In this case, the next combination is taken as new, outputted to output block 7, and overwritten in register 2. This again activates time sensor 5, regulating the selection interval for the received message.

In the case when the device contains the selector 8 of the code combination repetition number, the signal from its output goes to the second (setting) input of the timer 5, the selection time is set after which the time sensor 5 in its operation generates a signal to erase the information in register 2 .

The proposed device has a higher technical and economic efficiency than the known one, since its use is possible for a wider class of information transfer systems with crucial feedback. This is achieved by extending its functionality. The use of the known device in the POC-OJ type systems leads to the loss of information, the probability of which is estimated by the expression

- "

V 2

Considering code combinations equal. When, Ru,.

The proposed device reduces this type of loss. If there is no repeat number selector 8, then time sensor 5 is set to the maximum selection time t J. In this case, losses are possible when an error is received from the latter, for example, j-oe from {possible repetitions. In this case, the first (j-1) repetitions of the next (identical) message will be lectured (not received). The probability of losing soo & in this case is determined by the expression

P, “1.,

where P is the probability of distortion of one element in combination. „D

When, and, i.e. 10 times less than Roux,.

If, on the other hand, a selector 8 and a tunable time sensor 5 are used, on which time is set, {{Lectures tcjt depending on the number Ij of the combination received, this eliminates the loss of the indicated type and reduces the total information loss estimated by the expression

 CnPЗ With the same initial data 1 10,; 10 times less than for a known device.

Claims (2)

1. Device for preventing errors in data transmission systems according to aut. Ev, No., characterized in that, in order to increase the reliability of the device, a time sensor is introduced in it, the first input of which is connected to the second output of the control unit, and the output to the installation input of the recording register. 2.-Device according to claim 1, about tl, which is such that the selector number of the code combination is entered into it, the output of which is connected to the second time sensor input.