SU858054A1 - Device for transmitting information with compression - Google Patents

Description

(54) DEVICE FOR TRANSFER OF INFORMATION WITH COMPRESSION

The invention relates to signal conversion systems and can be used in telemetry and information processing systems using adaptive data compression techniques. In science and technology, adaptive compression methods for data represented by samples of a directly measured signal have been widely developed. However, due to a number of deficiencies in such systems, such as data redundancy, strong interference effects on measurement and a number of other reasons, in some cases the measured signal must be represented as decomposition coefficients according to orthogonal basic signals. Most intensively, they have recently begun to develop, from a system in l, using for processing signals in the bases of piecewise constant functions, in particular, signals in Walsh bases. This is due to the possibility of using discrete technology in the construction of such systems. An adaptive compression method using orthogonal expansions is known, which means that in a certain time interval the monitored signal is decomposed into basis orthogonal signals and is represented as a spectral decomposition with a given number of spectral components. The signal is then reconstructed and the accuracy of the restoration at the edges of the decomposition interval is estimated. In case of an error, i.e. the difference between the original and the recovered signal does not exceed the allowable value, the decomposition interval is increased by one step, and the whole procedure is repeated from the beginning. If the error is greater than the allowed value, the approximation procedure is terminated and the results are passed to the CO output. A device is also known that partially implements this method and contains a memory cell that integrates 38 blocks, multiplication blocks, a matrix recalculation circuit, an adder, subtractors, a comparison unit, a key circuit, control circuit and buffer memory unit. In this device, the length of the decomposition interval is set a priori L21. The disadvantage of such a device as of the method itself is that all calculations related to the calculation of spectral components, with an increase in the approximation interval, must be performed from the very beginning. Because of this, the time spent on processing the measured signal is large, in addition, it is necessary to remember the signal value over the entire interval of an approximation. Closest to the present invention is a Walsh analyzer device comprising a pulse generator, a reference signal generator, modulators, integrators, a control unit, a shift register, the input of the reference signal generator connected to the output of the pulse generator, the first output connected to the input of the control unit, the outputs the reference signal generator is connected to the first inputs of the corresponding modulators, the second inputs of which are interconnected and connected to the input of the device, the outputs of the modulators are connected to the first & 1 inputs corresponding to The main integrators, the second inputs of which are connected to the first output of the control unit, the integrator's outputs are connected to the first inputs of the corresponding memory blocks, the second inputs of which are connected to the second output of the control unit, the outputs are connected to the corresponding information inputs of the shift register, whose control inputs are connected to the output of the control unit 31. The disadvantage of such a device is that the decomposition of the analyzed signal is carried out strictly at a fixed time interval, when measuring In the approximation interval, the analysis of the measured signal must be started from the beginning, which reduces the speed of the device. The purpose of the invention is to increase the speed of the device. This goal is achieved by the fact that in a device for transmitting information with compression, containing a pulse generator, the first output of which is connected to the input of the generator of reference signals, the second output is connected to the first input of the control unit, the outputs of the generator of reference signals are connected to the first inputs of modulators, the second inputs which are connected and connected to the input of the device, the outputs of the modulators are connected to the information inputs of the integrators, the outputs of which are connected to the information inputs of the memory blocks, the outputs of the memory blocks connect The analog adder, multiplier and block are entered with the corresponding outputs of the device and information inputs of the shift register, the control input of which is connected to the first output of the control unit, the second and third outputs of which are connected respectively to the first control inputs of the integrators and the control inputs of the memory blocks. the comparison, the output of which is connected to the second input of the control unit, the fourth output of which is connected to the control inputs of the analog adder and multiplier, the information input of which o is connected to the shift register output, the output is connected to the auxiliary output of the device, the output of the analog adder is connected to the first input of the comparator, the second input of which is connected to the input of the device, the output to the second input of the control unit, the fifth output of which is connected to the second input of the reference generator signals, the output of the first memory block is connected to the second control input of the second integrator, the output of each next i-ro memory block is connected to the second control inputs (21-1) and 2i-ro integrator, the outputs of all memory blocks These are connected to the corresponding information inputs of the analog adder. In the proposed device, the analyzed signal is decomposed by an orthogonal Walsh basis adaptive to the signal over the interval. At the same time, with an increase in the decomposition interval, the conversion coefficients are recalculated from the coefficients calculated at the previous approximation stage. This makes it possible to reduce the number of calculations, and consequently the processing time, to process the signal at the rate of downtime and to refrain from having to remember the value of the entire signal in the decomposition interval.

Nd FIG. 1 shows a block diagram of the proposed device; in fig. 2 plots of reference signals generated by the reference signal generator; in fig. 3 is an example of diagrams of voltages at the outputs of the device.

The device contains (Fig. 1) control block 1, a generator of 2 pulses, a generator of 3 reference signals, modulators 4-, -4c, integrators, memory blocks, shift register 7, multiplier 8, analog adder 9, block 10 of comparison.

The principle of operation of the device is as follows.

The initial signal X (t) is analyzed at the decomposition interval T. In case the approximation error is less than the allowed predetermined error, the value of the decomposition interval doubles and becomes equal to 2T. The decomposition coefficients in the 2T interval are recalculated using the already calculated coefficients when analyzing the measured signal X (t) in the interval Tn, after which the approximation error is again estimated. If the error is greater than the allowable one, the results are output to the device and the next time interval is processed. If the approximation error is smaller, then the approximation continues.

The device works as follows.

Starting from the moment tg, the generator 3 of the reference signals generates signals of a special form, in the modulators the measured analog signal Ht) m of the reference signals is multiplied, after which the modulated signals are fed to the integrators. After the initial decomposition interval T, which corresponds to the first approximation at the time point C, the control unit I issues a command to the blocks according to which the voltage from the integrators is written to the blocks, and then in the analog adder 9 the restored signal is restored and normalized in block 1 at the end of the decomposition interval T at time t, taking into account the length of in

tormented decomposition of T-. The values of the recovered signal from the analog adder 9 are output to block 10, where the measured value is compared.

A (t) and the restored g (t) si1 of the deposit.

If the error between the signal (t) and its reconstructed value A (t) at the time t does not exceed the predetermined value, then the control unit 1 from block 10 is given a signal that sends a command to the integrators. By this command, the values of the signals from the memory blocks are written to the integrators, and the old signals in the integrators 5-5 are stored, now the newly recorded values will be the original ones in the integrators.

After that, the device continues the analysis of the original signal A (t), but already in the interval corresponding to the time interval from 1 to t, j and performs signal processing in the second half of the decomposition interval T, i.e. on the time interval from t to tn and performs signal processing in the second half of the decomposition interval T, i.e. on the time interval from t to t, after which at the end of the interval T, is the time t-, if the approximation error at the end of the interval T does not exceed the specified one, the device continues processing further, while the decomposition interval will be a segment equal to T, j 2T, ie from to to to, etc.

four

Finally, if, with a decomposition interval duration equal to (from t to tjj, the approximation error exceeds the tolerance, then block 10 issues a signal that control unit 1 rewrites the values of the decomposition coefficients from the integrators (1 to the memory blocks and issues a command to the register 7, the shift in which the values of the voltage coefficients from memory b-6 f memory are written to the shift register 7 and output successively to the multiplier 8. In the multiplier 8, the spectral decomposition coefficients are multiplied by the normalization factor eHTVl. taking into account the integration of integrators, and hence the length of the decomposition interval T.

The value of the normalization factor K is given from control unit 1 and depends on the length of the decomposition interval. Thereafter, signals are output to the device outputs. The control unit 1 embeds the integrators, as well as imposes a co-generator on generator 3, KOTOpbdt generates a new reference signal sequence (see Fig. 2b), and the device is ready to analyze the measured signal at a second interval of about 4 approximation interval TQ.

When the signal is restored, the duration of the decomposition interval is defined as the distance to the time between the time and the time of delivery of the bursts of the values of the decomposition coefficients. .

An example. Let the approximation error g be given (Fig. 3a). The initial signal D (1) is multiplied in modulators with support and signals (Fig. 3b), while the voltage at the outputs corresponds to three integrators 5-5f || have the form shown in FIG. 3 in. The first step of the approximation is analyzed on the interval T located in the interval from t to t. The signal reconstructed in the first step of the approximation (the plot of Fig. 3 g exactly repeats the original one, therefore the approximation error is zero. The device proceeds to the analysis of the next approximation interval T, located in the interval from tjj to t, In the second integrator 5 / at time L, the initial voltage from the first memory block is rewritten, and the third and fourth integrators 5, j, and 5D are rewritten to the initial voltage from memory block 6. After that, the signal (t) (Fig. 3a) continues to process on the time interval from t to tQ .. According to It is clear that the approximation error {(.3d exceeds the allowable 6d, therefore the further increase in the interval of approximation stops, and the values of the coefficients decompose and are outputted to an additional output The point t / is taken as the beginning of the next approximation interval.

Thanks to the proposed method of processing the analyzed signal, the device allows to reduce the number of

operations and increase speed by half. Since the processing of the analyzed signal is carried out at the rate of its arrival, there is no need for a special memory block to record the entire analyzed signal at the decomposition interval, which simplifies the system and further reduces the processing time, since it is not necessary to access the memory of a special storage device.

Claims (3)

1.Olhovsky Yu.B. et al. Data Compression for Telemetry, M., Soviet Radio, 1971, p. 154. 2. In the same place 213. 3. Besvetter Analysis and synthesis. signals using Walsh functions. Foreign radio electronics, 1972, p. 21 (prototype). 1 /