SU805381A1 - Telemetering system - Google Patents

Description

(54) TELEMETRIC SYSTEM

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The proposed system relates to telemetry and can be used to transmit messages over wired lines, waveguides, radio links, and r.

Systems are known about regular (cyclic) discretization, for example, with pulse-coa modulation (PCM).

A known system with pulse-code modulation comprising a series of amplitude-pulse modulators serially connected, an encoder, a station regenerator, a linear regenerator, a second station regenerator, a group decoder, a parallel set of keys and a parallel set of channel demodulators, as well as serially connected clock generator, channel distributor and clock generator on the transmitting side, and serially connected sync selector pulses and channel distributor on the receiving side of J.

The disadvantage of the pan system is low information content.

A more economical type of discrete representation of continuous messages is the various variants of differential pulse code modulation (DPCM).

Closest to the one proposed is the system in which it is used; (DPCM) and which contains a series-connected differential pulse code modulator consisting of a delay line, a difference circuit, a sampling device, a clock frequency generator and a quantizer, an encoder, a communication line, a decoder and an integrator 2.

A disadvantage of the known system is low noise immunity, since the failure of any binary bit to the opposite results in distortion over the entire subsequent length of its implementation, i.e. there is the effect of error accumulation due to the effect of interference in the communication channel. 36 noise immunity and informativeness of the system. This goal is achieved in that the system containing the coding block, the output of which through a serially connected communication line and the decoding block is connected to the input of the integrator block, is inserted into the system containing the coding block a feedback channel consisting of successively connected coding block, communication line and decoding block, the inputs of the first orthogonal Walsh function converter soy dinenets with system inputs, outputs with corresponding first inputs of a differential pulse unit of HC-Code modulators, the second inputs of which are connected to the corresponding outputs of a feedback channel decoding unit, outputs of the integrator unit are connected to the corresponding inputs of a feedback channel coding unit and corresponding inputs the second orthogonal transducer of the Walsh function, the outputs of which are connected to the outputs of the system. Due to this, the accumulated errors from failures are periodically corrected, and the errors resulting from failures are reduced N times, as in the second orthogonal transducer each received signal is divided into PTGs. The drawing shows the block diagram of the telemetry system. The system contains an orthogonal Walsh function converter 1, a unit 2 of differential pulse-code modulators, a coding unit 3, a communication line 4, a decoding unit 5, a integrator unit 6, a feedback channel 8 encoding unit 7, a channel 8 decoding unit 8 and a line 1O channel 8 communication, the second orthogonal transducer 11 Walsh functions. The orthogonal transducers 1 and 11 serve for linear time-continuous orthogonal transformation with the Walsh matrix W of the input ensemble of signals X (i;) and C (H;) into ensembles C (t) (tyHt (i) -;;:: VW W where N - number of information channels in the system. Converters 1 and 1O can be implemented, for example, on the basis of C-in (common adders, the number of which is equal to 1 number of information channels, and the weight of each input corresponds to an element of matrix W. When the Walsh transform is implemented, the weights of all inputs differ only in signs, since the elements of the Walsh matrix only ± 1 is accepted. Block 2 is used for differential pulse-code modulation of an ensemble of continuous signals C (i -) - Modulators are similar to those used in the well-known and are designed to compute and quantize to the minimum number of levels (usually two levels) the current and predicted values of the input signal. Prediction is based on zero extrapolation. In addition, block 2 has N setup inputs for inputting initial conditions (correction signals). Blocks 3 and 7 of the decoding are intended to be transmitted on the communication line, respectively, 4 and 10 codes of modulators. The communication lines 4 and the communication lines 10 of channel 8 are designed to transmit discrete information over a distance based on one or another signal multiplication {temporal, frequency or orthogonal). The decoder unit 5 and the decoder unit 9 for the feedback channel 8 are used to decode the input group signal and distribute it to the corresponding N outputs. The integrator unit 6 serves to reconstruct the continuous ensemble from the difference code sequences and is N integrators (adders). Telemetry system works as follows. The orthogonal transducer 1 continuously in time produces a linear orthogonal transformation of the ensemble of input signals X (i, j of information channels into the ensemble C (t) vvvtt). In the block of a continuous ensemble of signals C (t) with a constant clock frequency, the differences (increments) between the actual value C (i,) and the predicted value in each information channel are determined. The increments of the signals of all information channels are encoded in block 3 and transmitted on link 4. After decoding in block 5, these increments arrive at the inputs of block 6 of the integrators (for each information channel there is its integrator), where the transmitted signals C (4;) g are restored, that is, the mozel C (t) is formed at the outputs of block 6. In the converter 10, an inverse orthogonal transformation occurs, as a result, the model of the input signal ensemble X) is formed at the outputs of the converter 10. To eliminate the error accumulated during the delta-modulation in the communication channel, the system periodically transmits the output voltage of the integrators of block 6, t, i.e. C (-tJ), through the feedback channel. For most real volumes, it can be considered that the information on the reverse link is transmitted without failures for the aircraft, the ground transmitting station has a radiated power that is ten times the power of the onboard transmitter). The values of Cj (t, j) obtained via the reverse channel 8 are entered into block 2 instead of the predicted values {if the communication channel has not failed since the last correction, then C) in this communication channel is the same as value). Difference H; ) - - C {t j) will decrease with each direct transfer tact by the magnitude of the approximation error in accordance with the algorithm of operation of Bless 2, i.e., the correction of failures occurs. To reduce the error due to failures to the two points of correction in the proposed system, not the telemetric signals X (-i) themselves are transmitted via channel 4, but signals C) generated from them using converter 1. From received signals), some of which may contain errors due to failures of the fc SB® converter 1O, models of telds are formed — metricable signals X (i) (|. At the same time, the error reduces c ht times and is distributed to all N information channels, t E. There is a decrease in the maximum error value of failures. The same effect reduces the error times that can occur due to faults in the feedback channel 8. The probability of faults in the feedback channel is negligible, since the amount of information transmitted through 1O St. is several times less than on line 4, which ensures very high noise immunity even with the same radiation power. For example, if the correction is performed N times less often than the frequency of the delta module in each information channel, then . The forward direction should be transmitted at each transmission cycle N bits {by the number of information channels), and in reverse - P bits {by the number of bits of the reference code); in real systems, N I (the value of N reaches hundreds, and the value of n does not exceed yes). Thus, the proposed system is more robust and more informative than the known one. The formula obtained by the Telemetric System contains a differential moduli module module, the outputs of which are connected to the corresponding inputs of a coding unit, the output of which is connected through a serially connected communication line and decoding unit to that enhancement of noise immunity and informativeness of the system, orthogonal transducers of Wopsch functions and a feedback channel, C (x, are added from the series-connected coding block, The links and the decoding unit, the inputs of the first orthogonal Walsh function converter are connected to the system inputs, the outputs to the corresponding first inputs of the differential pulse-CHO module. CODE modulators, the second inputs of which are connected to the corresponding outputs of the feedback channel decoding unit, the outputs the integrator unit is connected to the corresponding inputs of the coding block of the feedback channel and the corresponding inputs of the second orthogonal Walsh function converter, the outputs of which are us with the system outputs. Sources of information taken into account in the examination 1. Bosy N. D., Ignatov V. A. Multichannel systems of information transfer. M., Knowledge, 1974, p. 28-31, fig. 9. 2.Venediktov MD and others. Delta modulation, theory and application. M., Sv.T. 1976, p. 23-25, fig. 22 {prototype).

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Claims (1)

Claim A telemetry system containing a block of differential pulse-code modulators, the outputs of which are connected to the corresponding inputs of the encoding unit, the output of which is connected through a series-connected communication line and the decoding unit to the input of the integrator unit, characterized in that, in order to increase the noise immunity and information content of the system, Orthogonal converters of Walsh functions and a feedback channel, consisting of a series-connected coding block, a communication line, and a deck block, are introduced into it coding, the inputs of the first orthogonal transducer of Walsh functions are connected to the inputs of the system, the outputs are connected to the corresponding first inputs of the block of differential pulse-code modulators, the second inputs of which are connected to the corresponding outputs of the decoding unit of the feedback channel, the outputs of the integrator block are connected to the corresponding inputs of the block encoding the feedback channel and the corresponding inputs of the second orthogonal converter of Walsh functions, the outputs of which are connected to the outputs of the system.