DE1202184B - Method for the simultaneous remote transmission of several pieces of information - Google Patents

Description

Method for the simultaneous remote transmission of several pieces of information The invention relates to a method for simultaneous remote transmission several pieces of information, especially several commands. Such remote transmissions are required in various areas of technology, e.g. B. for remote control of missiles and the like or in telemetry and telecontrol technology.

Method for the simultaneous remote transmission of several pieces of information are known in various embodiments. In particular, the principle is known to convert the information into impulses and as a periodic sequence more rectangular Transmitting pulses, the time interval from a reference grid of information is equivalent to. Such measures are not readily available for all applications suitable because interference of atmospheric origin or arbitrary, via jammers Generated disturbances can falsify the information, as well as the content of the Information can easily be determined, i.e. decrypted, by third parties.

In detail, for example, is the transmission of several measured variables known by means of an amplitude modulated VHF signal by pulses, wherein the time interval between the pulses and a reference grid depicts the information. The information pulses become variable time intervals from the raster pulses radiated. The impulses are identified here by different ones Modulation height.

In addition, it is known in connection with metrological problems continuous electrical quantities, for example the length of a material or correspond to the angle of revolution of a mechanical shaft, measured by means of pulses and to dissolve it into impulses. However, this contributes to the problems mentioned at the beginning just as little as the fact that the coded transmission of fixed switching commands and the control of their execution through feedback to remote control systems in Power supply companies and the like is common.

The invention is based on the object of a method for simultaneous Remote transmission of several pieces of information to indicate which one against atmospheric or arbitrary interference and unauthorized decryption is largely secure.

The invention relates to a method for the simultaneous remote transmission of several pieces of information, in which the information is converted into pulses and transmitted as a periodic sequence of rectangular pulses, the time interval from a reference grid corresponding to the information. The invention consists in that, on the transmitter side, the information is transformed into a sequence of multiple pulses whose individual pulses begin simultaneously and whose length represents the information, and that these raster and command pulses are converted into pulse groups of n (n > 3) encrypted pulses Pulse duration must not be longer than a raster or command pulse, and that the encrypted pulses are sent with assignment of n different transmission frequencies and are separated, decrypted and converted back to length-modulated pulses on the receiving side.

A particularly advantageous circuit arrangement for the inventive Process that is of particular importance because of its simplicity and functional reliability is characterized in that it has an encryptor on the transmission side Transmission frequency generators for generating fixed transmission frequencies and a logical one Circuit as well as a sampling generator working together with a time-voltage converter has that from the information fed into the time-voltage converter a fixed grid of raster pulses and command pulses can be generated, the time intervals between the command pulses and the raster pulses map and that the logic circuit with the help of a pulse generator for the encrypted pulses from each raster pulse and each command pulse at least three encrypted pulses generated, which the transmission frequency generators key and that on the receiving side it has filters which correspond to the transmission frequencies cooperate with another logic circuit and that of the logic circuit the number of information corresponding ripple generators are assigned and these generate the length-modulated pulses.

In the following, the invention is explained in more detail with reference to the figures with regard to its mode of operation and the advantages that can be achieved; it shows F i g. 1 schematically shows a diagram of electrical pulses which, for example, represent commands or other information, FIG . 2 schematically shows the block diagram of a transmitter for transmitting coded signals associated with such pulses, FIG . 3 in the same representation as FIG. 2 shows an embodiment of a receiver for receiving such coded signals and for converting them back into pulses which in turn represent commands or other information.

The invention explained with reference to the figures is for the transmission of Information determines which can be continuous or discontinuous. It can be commands, measured values or the like.

A repetition period is defined by discontinuous information, which in F ! G. 1 is designated with TR and can be selected by setting between time limits, but has a fixed value for a given transmission. Information of a first type is defined by a sequence of square pulses S1 with a uniform temporal distribution, each pulse having a steeply rising leading edge which is separated from a trailing edge by the duration t 1 .

Information of a second type corresponds to a second pulse sequence labeled S2. These pulses are similar to the pulses S 1, and the ImpulseS1 and S2 have a common, steeply rising leading edge, while their rear edges may be different.

Since the continuous information transmitted through each channel corresponds to the duration t 1 and t 2 of the pulses S1 and S2 , the values of the output signals expressing this information are proportional to the ratio tlITR and t21TR, respectively.

Such information can be used to access a moving Body to transmit guidance commands, e.g. B. for the direction and the speed, or for a missile for direction and altitude.

The movement of such a movable body in a straight line is then determined so that it corresponds to the equality of the above relationships with one another and that with the value 0.5. If z. B. t 11TR is greater than 0.5 , causes the setting of the control-determining adjusting mechanism a deflection of the movable body z. B. to the right. while a smaller value of this ratio causes a deflection to the left.

In Fig. 2, there are shown schematic diagrams corresponding to three types of continuous information, but the above embodiment is applicable to any number of types of continuous or discontinuous information.

For the transmission, a conversion of the in FIG. 1 provided in coded radio signals, and on the receiving side, after decoding and separating the information channels, pulses with the same shape as at the input of the transmitting side are found at the outputs. The in F i g. The arrangement shown in FIG. 2 by means of a block diagram now enables the coding to be carried out on the transmission side.

This arrangement thus comprises a generator Gr for generating raster pulses, which is connected to time-voltage converters Mel, Me2 and Me3 as well as to an encoder Co, to which the outputs of the time-voltage converters also lead. The inputs of the time-to-voltage converters Mel, Me2, Me3 are connected to terminals U, V and W via which the electrical translations of the information to be transmitted arrive in the form of the signals shown in FIG. 1 and analog signals.

Corresponding to the diagrams shown (for the generator Gr and between the connecting lines between the time-voltage converters Me 1, Me2, Me3 and the encoder Co , a series of corresponding diagrams is shown, each of which has the ordinate axis in intensities and the abscissa axis in times is divided) is the raster pulse in the form of electrical pulses 1 in the first diagram of FIG . 1, which marks the beginning of a steep leading edge of the pulses S 1 and S2. 2 shown. The raster pulses 1 are equidistant from one another and separated from one another by the reference time TR.

The time-voltage converter Mel supplies the EncoderCo with command pulses 2 which are shifted by the duration t 1 against the raster pulses 1, and these command pulses 2 are also equally spaced from one another. The change in the duration depends on the size of the electrical value applied to terminal U , which actuates the corresponding time-voltage converter Mel in a corresponding manner.

Likewise, the time-voltage converter Me 2 forms the command pulses 3 with the same spacing according to the magnitude of the electrical value applied to the terminal V, each of which, however, is shifted by the duration t2 with respect to each raster pulse 1. The same applies to the command pulses 4 formed by the time-voltage converter Me 3 , the separation of which from the raster pulses 1 corresponds to a duration t3.

These pulses 1 to 4 pass via known devices, not described in detail, to the encryptor Co, in which each of the pulses 1, 2, 3 and 4 is transformed.

For this purpose, the encryptor is connected to three transmission frequency generators Gf 1, Gf 2 and Gf 3 , which operate with fixed transmission frequencies f 1, f 2 and f 3 staggered frequencies, which are shown schematically in FIG. 2 visible lines are shown, the lengths of which are approximately proportional to these transmission frequencies.

The encryptor Co and the transmission frequency generators Gf 1, Gf 2 and Gf 3 operate in such a way that each raster pulse 1 is converted into a train of three elementary pulses, which are denoted by the reference character R in the diagram below in FIG. The diagram has an abscissa axis 0-t divided into times and an ordinate axis 0-f divided into transmission frequencies. At the point of each raster pulse 1 there is a composite pulse R, which consists of three elementary pulses with the successive transmission frequencies f 1, f 3 and f 2.

The pulse train 1 assigned to each raster pulse also consists of three elementary pulses with the successive frequencies f 2, f 3 and f 1.

The pulse train II corresponding to the command pulses 4 consists of three elementary pulses with the successive frequencies f 2, f 1 and f 3.

Finally, the pulse train III consists of three elementary pulses which correspond to the command pulse 3 and whose successive frequencies are f3, fl and f2 .

Obviously one gets through such a change in the order the transmission frequencies of each elementary pulse a discontinuous frequency modulation, while the distribution of the various command pulses is continuous over time Modulation is.

In the example described, each command pulse has three elementary pulses on, however, it is clear that a larger number of elementary pulses are also chosen can be.

In the case of n elementary pulses with different frequencies, and if only sequence changes are permitted without repetition, n! different impulses are formed. In order to avoid the risk of interference from wobbling, the two permutations must be suppressed, in which the frequencies forming them are arranged according to their values in ascending and descending order. The number of possibilities is: N, = ni-2 Regardless of this general case, it can be seen that for the remote control described above by way of example it is sufficient to divide the command pulses and the raster pulse into three elementary pulses with different transmission frequencies, which is actually gives four permutations of the above kind.

As stated above, such a method protects the reception against interference from wobbling, and the use of three different transmission frequencies also makes interference from a narrow band determined by detection difficult. Furthermore, since a large amount of information is not required for such a transmission, the number of pulses per second is low, so that a high peak output can be achieved with a relatively low average output. The energy transmitted by an elementary pulse is therefore large. From this it follows that each impulse is easily recognizable above the background noise, which is generated by a disturbance with a broad band or even an all-out disturbance (T).

The necessary coding does not seem to create any actual secrecy in the transfer, however, it aims to imitate the same to the utmost to complicate and also gives it a particularly high level of security against interference, no matter whether this is done with a wide band or a narrow band.

As shown in FIG. 3 , the signals arriving at the receiving antenna Ar and the signals supplied by a receiver R at its output terminal have a form which corresponds to that of the diagram below in FIG. 2 corresponds, and which in the diagram at the top left in FIG. 3 is reproduced.

The output terminal of the receiver is connected to the inputs of the frequency filters F1, F2 and F3 , which select the corresponding pulses with the frequencies f 1, f 2 and f 3. The outputs of the filters are applied in parallel to the inputs of a logic circuit Ls of a known type, which is intended to separate the command channels and is not described in further detail.

Such a logic circuit has four outputs. The first output 5 is connected to an arrangement of tilt generators B 1, B 2 and B 3 via one of the inputs of these tilt generators. The second output 6 is connected to the second input of the tilt generator B 1 , the third output 7 is connected to the second input of the tilt generator B 2 and the fourth output 8 is connected to the second input of the tilt generator B 3 . These ripple generators and outputs are designed so that when a pulse arrives via the output 5, the three ripple generators B 1, B 2, B 3 are made ready for operation at the same time. The tilting of the tilt generators B 1, B 2 B 3 , however, takes place individually when the pulses arrive via the relevant outputs 6, 7 and 8.

The outputs 6, 7, 8 of the relaxation generators B 1, B 2, B 3 are connected to the terminals X, Y and Z for evaluating the transmitted information. In the diagrams shown on the left in the figure, the abscissa axes are in times and the ordinate axes z. B. divided into currents. Each of these diagrams represents impulses which occur at the outputs to which the diagrams are connected by dash-dotted arrows.

A pulse train R of raster pulses causes z. B. that the three above-mentioned elementary pulses arrive at the filter F 1 , and the output of the filter Fl lets a command pulse 10 of the transmitter frequency f 1 through, which is aligned with the first elementary pulse of the pulse train R of raster pulses. The two other filters F 2, F 3 let through command pulses 11 and 12 at their outputs in the correct order, which correspond to the other elementary pulses and have the order 10, 11, 12, as shown on the diagrams assigned to the outputs of these filters.

When passing through the logic circuit Ls, a raster pulse 100 occurs at the output 5 , which makes the three relaxation generators B 1, B 2, B 3 ready for operation, so that currents occur at the terminals X, Y and Z whose current strengths Isl, Is2 and Is3 correspond to the values entered in the diagrams at the bottom left of the figure. Therefore, rising leading edges of the pulses S1, S2 and S3 occur at these terminals.

When the pulse train 1 arrives at the filters F 1, F 2, F 3 , command pulses 13, 14 and 15 appear at the outputs of the same one after the other and in this order, which are shown in the corresponding diagrams. When passing through the lo-ische circuit Ls, the three commands in the ZD 9 pulses 13, 14 and 15 in the output 6 generate a command pulse 101 whose position in relation to the position of the raster pulse 100 is the same as the position of the pulse train 1 in relation to that of the pulse train R. The command pulse 101 causes the ripple generator B 1 to tilt, whereby the pulse S 1 is interrupted by a falling edge (end of the pulse).

Likewise, from FIG. 3 shows that the pulse train III later causes the interruption of the pulse S 3 and the pulse train II finally causes the interruption of the pulse S2.

The above work cycle is repeated when a new pulse train R arrives in the receiver Re.

As above with reference to FIG. 1 , the relative duration of the pulses S1 and S2 forms the required time modulation, which gives the transmitted continuous information its values, while the channels are separated by decoding to identify the transmission frequency sequences in the trains of elementary pulses.

In the above examples, command pulses 4 were taken into account, as if it were a question of the transmission of a continuous piece of information. These Command pulses 4 could correspond to discontinuous information and only appear at the moment this information is triggered, as explained above became.

Such a transmission method makes it possible to achieve increased protection against interference by changing the channels. Namely, if the transmission frequencies f 1, f 2 and f 3 are the same distance apart, a simple change of the frequency of the local oscillator on the transmission side as well as on the reception side is sufficient to carry out a code change. A plurality of high-frequency channels can be provided in each transmission, of which the least disturbed one is used thanks to a control circuit that sends a channel change command as soon as one of the three elementary pulses fails during a repetition period, or when more than three elementary pulses arrive in a pulse train are.

This system for Zählun g of the elementary pulses is of course only applied to the information channels on which continuous information arrive.

With the channels receiving continuous information and when no channel gives a satisfactory reception, the training is made in such a way that that the controlled parts in middle positions (e.g. a movement in straight Line), which is an interference protection measure that stops as soon as a satisfactory reception occurs again on one of the channels.

C.

Claims (2)

1. A process for the simultaneous remote transmission of multiple information wherein the information is converted into pulses and transmitted as periodic sequences rectangular pulses, wherein the time interval corresponds to from a reference grid of the information, d a d u rch g e k ennzeichnet that the transmitter side the information are transformed into a sequence of multiple pulses, the individual pulses of which begin simultaneously and whose length represents the information, and that these raster and command pulses are converted into pulse groups of n (n > 3) encrypted pulses, the pulse duration of which must not be longer than a raster or command pulse, and that the encrypted pulses are transmitted with assignment of n different transmission frequencies and are separated, decrypted and converted back to length-modulated pulses on the receiving side. 2. Circuit arrangement for the method according to claim 1, characterized in that it has an encoder (Co) on the transmission side with transmission frequency generators (Gf 1, Gf 2, Gf 3) for generating fixed transmission frequencies and a logic circuit and one with a time-voltage converter (Mel, Me2 Me3) which so co-operating scan generator, that from the time-voltage converters (Mel, Me2, Me3) fed information a fixed grid of raster pulses and command pulses can be generated, wherein the time spacings of the command pulses of the raster pulses map the information and that the logic circuit with the help of a pulse generator for the encrypted pulses from each grid pulse and each command pulse generates at least three encrypted pulses, which the transmission frequency generators (Gf 1, Gf 2, Gf 3) key and that they receive the transmission frequencies corresponding filter (F1, F2, F3) , which with a further logic circuit (Ls) cooperate and that the logic circuit (Ls) of the number of information corresponding toggle generators (B1, B2, B3) are assigned and these generate the length-modulated pulses. Considered publications: C Deutsche Auslegeschriften No. 1028 469, 1 043 879; WP Venzke, "Remote control systems in the energy supply company", W. Girardet, Essen, 1950, pp. 56 to 70.