EP2280503A2 - Method for wireless transmission of information composed of data packets - Google Patents

Abstract

The method involves providing an algorithm for computing time slot information (3) for time slots to transmit the data packets. The time slots have irregular distance from one another. The time slot information is generated using the algorithm in the control center. The generated time slot information is transmitted to transmitting- or receiving devices (1a,1b). The transmitting- or receiving devices are provided in missiles (F1,F2). The missiles are started and the data packet is transmitted from the transmitting- or receiving devices to another transmitting- or receiving device (2).

Description

The invention relates to a method for the wireless transmission of information formed from data packets from a provided in a missile first transceiver to a provided in a control center second transceiver.

In particular, the invention relates to the transmission of image data from a missile to a control center. The control center can be, for example, a helicopter from which the missile has been launched.

There are known jammers or so-called "jammers" with which a wireless transmission of information from the first to the second transceiver can be disturbed. In order to make possible a transmission of information which is as insensitive as possible to jammers, different methods are known. For example, the frequency band used for transmission can be constantly changed. With modern digital radio bearings, however, it is possible to simultaneously monitor a variety of frequency bands and thus to drive a jammer.

Another method for complicating the disturbance of a wireless transmission of information is to encode the information according to the so-called "spread-band transmission method" and thus to hide in the "noise". - Meanwhile, however, algorithms have been developed with which such encoded transmission of information can be clarified and disturbed.

The object of the invention is to eliminate the disadvantages of the prior art. In particular, a method for the wireless transmission of information formed from data packets is to be specified, which is as insensitive as possible to an attack by means of a jamming transmitter or jammer.

This object is solved by the features of claim 1. Advantageous embodiments of the invention will become apparent from the features of claims 2 to 12.

1. a) Bereitstellen eines Algorithmus zur Berechnung einer Zeitfensterinformation für Zeitfenster zur Übermittlung der Datenpakete, wobei die Zeitfenster einen unregelmäßigen Abstand voneinander aufweisen,
2. b) Erzeugen der Zeitfensterinformation unter Verwendung des Algorithmus bei der Leitstelle und Übergabe der erzeugten Zeitfensterinformation an die erste Sende-/Empfangseinrichtung und
3. c) Start des Flugkörpers und Übermittlung von Datenpaketen lediglich innerhalb der durch die Zeitfensterinformation definierten Zeitfenster von der ersten an die zweite Sende-/Empfangseinrichtung.

In accordance with the invention, a method for the wireless transmission of information formed from data packets from a first transmitting / receiving device provided in a missile to a second transmitting / receiving device provided in a control station is proposed with the following steps:

1. a) providing an algorithm for calculating a time window information for time windows for transmitting the data packets, wherein the time windows are at an irregular distance from each other,
2. b) generating the time window information using the algorithm at the control center and transferring the generated time window information to the first transceiver and
3. c) start of the missile and transmission of data packets only within the time window defined by the time window information from the first to the second transceiver.

In departure from the prior art, the invention proposes not to transmit the information continuously but "pulsed" or in time windows. The time windows intended for the transmission of the data packets are calculated with an algorithm such that their sequence is irregular or pseudorandom. Algorithms for generating pseudo-random number sequences are well known in the art. Such algorithms may include, for example, a modulo function, a ZZG function, or the like. From the generated pseudorandom numbers or random numbers, a time interval of two consecutive time windows can be calculated. Because of the pseudo-random sequence of timeslots generated by the algorithm, it is impossible for a jammer to predict and disturb the occurrence of the next succeeding time window. The inventive method allows interference-insensitive transmission of information formed from data packets from the first transmitting / receiving device to the second transmitting / receiving device.

For the purposes of the present invention, an "information" can consist of a plurality of "data packets". The "data packets" forming an "information" can be transmitted in several successive time windows.

According to an advantageous embodiment of the invention, the calculation of the time window information takes place on the basis of a parameter which is taken from a set of different parameters. In this way, different pseudorandom number sequences can be generated in a simple manner. Ie. Each time the algorithm is used, another pseudorandom sequence of timeslots is defined. This makes it impossible to elucidate the coding thus generated, for example by recording and recording the sequence of the time windows.

Advantageously, the parameter used is a time correlated with a start time of the missile and / or a datum correlated therewith. Such a parameter can not be clarified in practice. Even with knowledge of the algorithm used, it is virtually impossible to clarify the time window information thus calculated without knowing the parameter used.

According to a further advantageous embodiment of the invention, at least a part of the time window is assigned a different frequency band with the algorithm. For this purpose, the algorithm may for example comprise a further algorithm with which further pseudo-random numbers are generated, which in turn are specific to the use of a particular frequency band. As a result, the time windows do not occur only at a random interval. In addition, it is also possible that they are assigned to a frequency band which is randomly selected from a plurality of frequency bands. This measure also helps to make the method particularly insusceptible to the effect of a jammer.

According to a further embodiment, the transmission of the data packets takes place in the spread-band transmission method. Advantageously, the Spreizbandübertragungsverfahren is optionally only upon detection of a Jammer used. The detection of the jamming transmitter can take place with a detection device known from the prior art, for example from the control center. Once a jammer has been detected, the control center can switch from the normal transmission method to the spread spectrum transmission method. In the normal transmission method is advantageously the entire bandwidth of the frequency band used for the transmission of user data, such as image data available. In this case, a large amount of user data can be transmitted per unit of time. In the case of the spread spectrum transmission method, on the other hand, because of the required coding, the proportion of user data transmitted per unit time is lower.

In particular, the optional switching from a normal transmission method to a spread spectrum transmission method further contributes to the increase of the interference resistance of the method.

According to a further advantageous embodiment, current first location coordinates of the missile are inserted into the information transmitted from the first to the second transceiver. This allows precise monitoring of the trajectory of the missile. For this purpose, additional data about a flying height of the missile can be inserted into the information.

According to a particularly advantageous embodiment of the invention, a distance to the missile is determined from the first location coordinates and present at the control center second location coordinates, and depending on the determined distance is a transmission power to one for the transmission of data packets from the second to the first transceiver station necessary minimum value set. Ie. the transmission power of the second transmitting / receiving station is adapted to the distance to the first transmitting / receiving station, wherein the transmission power is kept as low as possible. This measure also makes it difficult to elucidate a radio link between the first and the second transceiver station by means of a jamming transmitter.

The first and / or second location coordinates can be determined by means of astronavigation, terrain-referenced navigation or using SAR images or GPS data. In particular, the use of GPS data allows easy and fast determination of the location coordinates.

The method according to the invention can be carried out not only unidirectionally, but also bidirectionally. For this purpose, for wireless exchange of information between the first and the second transceiver means of the algorithm, first time slot information for transmitting data packets from the first to the second transceiver station and second time slot information different from the first time slot information for transmission of data packets are generated from the second to the first transceiver. Since the time windows defined by the first and second timeslot information are different from each other, it is ensured that they do not overlap.

The generation of the first and second time windows is expediently carried out on the basis of a common time base. For this purpose, the first and the second transmitting / receiving device may include a high-precision quartz-stabilized counter, which is started at the same time with the transfer of the calculated time window information. This allows a highly accurate generation of the respective time window.

To further increase the security of the method, the transfer of the time window information generated by the algorithm to the first and / or second transmitting / receiving device can take place via a cable connection. Such a connection is particularly secure against eavesdropping.

Fig. 1

schematisch die Übergabe einer erzeugten Zeitfensterinformation,

Fig. 2

schematisch einen Informationsaustausch zwischen einem Flugkörper und einem Hubschrauber und

Fig. 3

schematisch erzeugte erste und zweite Zeitfenster.

Embodiments of the invention will be explained in more detail with reference to the drawings. Show it:

Fig. 1

schematically the transfer of a generated time window information,

Fig. 2

schematically an exchange of information between a missile and a helicopter and

Fig. 3

schematically generated first and second time windows.

Fig. 1 schematically shows a control center L, which may be, for example, a helicopter. In the control center L several missiles F1, F2 are added, which are each provided with a first transmitting / receiving device 1a, 1b. The reference numeral 2 denotes a second transmitting / receiving device, which is provided in the control center L. At the transceiver stations 1a, 1b, 2 are, for example, radios which can transmit and receive on a multiplicity of different frequency bands. Each of the transceivers 1a, 1b, 2 comprises a memory device (not shown here).

The reference numeral 3 denotes a device for generating a time window information. It can be a computer which is provided with a program for generating the time window information. The device for generating the time window information 3 is connected via cable 4 to the first transmitting / receiving devices 1a, 1b and the second transceiver 2.

If a missile F1, F2 is to be started from the control center L, a first 11a and a second time window information I2 are generated with the program provided in the means for generating time window information 3. For this purpose pseudorandom number sequences are generated with an algorithm. For example, based on the generated pseudo-random number sequences, alternately the beginning of a first and a second time window are set. The time windows can each have a constant duration.

Fig. 3 schematically shows first time window t1a, which are generated on the basis of the first time window information I1a and used for the transmission of data packets from the first transceiver 1a to the second transceiver 2. In Fig. 3 are designated by t2 second time windows, which are generated on the basis of the second time window information I2 and used for the transmission of data packets from the second transceiver 2 to the first transceiver 1a, 1b. How out Fig. 3 can be seen, the first and the second time windows occur irregularly; they do not overlap.

Fig. 2 shows a further embodiment. A first missile F1 started by a control center L, in this case a helicopter, transmits image data D and first local coordinates K1 to the second transceiver 2 provided in the control center L, from the master L, with the first transceiver 1a provided therein second location coordinates K2, which define the position of the control center L, a distance A to the first missile F1 can be determined. A transmission power of the second transmitting / receiving device 2 can be reduced so far that just a secure radio connection with the first transmitting / receiving device 1a is possible. For a clarification of the radio connection for a jammer is considerably more difficult. If a jammer is detected by the control center L, in addition, the data packets transmitted with the first 1a, 1b and second transceiver 2 can be encrypted in the spread path transmission method. Besides, it is also possible to change the frequency bands used for information transmission at random. Again, a random frequency band sequence is generated with the means for generating time slot information 3 based on a pseudorandom number sequence. The result obtained is stored in the first 1a and the second transceiver 2. On the basis of the time window information present only in the case of the first 1a and / or second transceiver 2, a particularly interference-free radio connection is possible.

To generate the pseudo-random number sequences, a parameter can be used which changes constantly. Conveniently, the time and the date of the respective use of the algorithm for generating the pseudo-random number sequence can be used for this purpose.

LIST OF REFERENCE NUMBERS

1a,

1b first transmitting / receiving device

2

second transmitting / receiving device

3

Device for generating time window information

4

cable connection

A

distance

D

image data

F1, F2

missile

I 1a

first time window information

I2

second time window information

K1

first location coordinates

K2

second location coordinates

L

control center

Claims (12)

Method for the wireless transmission of information formed from data packets from a first transmitting / receiving device (1a, 1b) provided in a missile (F1, F2) to a second transmitting / receiving device (2) provided in a control station (L) with the following steps . a) providing an algorithm for calculating a time window information (I1a, 12) for time windows for the transmission of the data packets, wherein the time windows are at an irregular distance from each other, b) generating the time window information (I1a, 12) using the algorithm at the control center (L) and transferring the generated time window information (I1a, 12) to the first transceiver device (1a, 1b), c) start of the missile (F1, F2) and transmission of data packets only within the time window defined by the time window information (I1a, 12) from the first (1a, 1b) to the second transceiver (2). Method according to claim 1,
wherein the calculation of the time window information (I1a, 12) is based on a parameter taken from a set of different parameters. Method according to claim 2,
wherein as a parameter with a start time of the missile (F1, F2) correlated time and / or a correlated date is used. Method according to one of the preceding claims,
wherein the algorithm allocates at least a portion of the time slots to a different frequency band. Method according to one of the preceding claims,
wherein the transmission of the data packets takes place in the spread spectrum transmission method. Method according to claim 5,
optionally, the spread spectrum transmission method is used only upon detection of a jammer. Method according to one of the preceding claims,
wherein in the from the first (1a, 1b) to the second transmitting / receiving device (2) transmitted information current first location coordinates (K1) of the missile (F1, F2) are inserted. Method according to claim 7,
wherein from the first location coordinates (K1) and at the control center (L) present second location coordinates (K2) determines a distance (A) to the missile (F1, F2) and depending on the determined distance (A) a transmission power to one for transmission of data packets from the second (2) to the first transceiver station (1a, 1b) necessary minimum value is set. Method according to claim 7 or 8,
wherein the first (K1) and / or second location coordinates (K2) are determined by means of astronavigation, intertial navigation, terrain-referenced navigation or using SAR images or GPS data. Method according to one of the preceding claims,
wherein for the wireless exchange of information between the first (1a, 1b) and the second transceiver (2) by means of the algorithm a first time window information (I1a) for the transmission of data packets from the first (1a, 1b) to the second transmission / Receiving means (2) and a second time slot information different from the first time slot information (I1a) (12) for the transmission of data packets from the second (2) to the first transceiver (1a, 1b) are generated. Method according to one of the preceding claims,
wherein the generation of the first (I1a) and second timeslot information (12) is based on a common time base. Method according to one of the preceding claims,
wherein the transfer of the time window information (I1a, 12) generated by the algorithm to the first (1a, 1b) and / or the second transceiver device (2) takes place via a cable connection (4).

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