Siemens Aktiengesellschaft

Alcatel N.v.

Standard Elektrik Lorenz Ag

Norbert Erbes

Dietrich Rother

Herbert Baumann

Kurt Hechfellner

Christoph Prasse

Kur Hechfellner

Rainer Vogel

A relay station utilizes the frequency hopping principle for the purpose of protection against intentional interference. Normally, the frequency hopping range available cannot be utilized for the frequency hopping operation because an indispensable minimum signal-to-noise ratio must be observed between the receiving frequency and the transmitting frequency of the relay station. In order to eliminate this disadvantage, the transmitter of the relay station is synchronized to the receiver by way of an interface connection and, with the aid of this synchronization, the desired frequency hopping in the entire available frequency hopping range for the transmitter and the receiver of the relay station can be controlled pursuant to observation of the required minimum signal-to-noise ratio.

Relay station for wireless communication traffic

A data-processing system includes an address bus and a data bus operatively coupled to a central processing unit, main memories, and control circuits for peripheral equipment, information carried on the data bus being encrypted. An encryption and decryption device is operatively coupled between the data bus and the central processing unit, for encrypting and decrypting the information.

Data processing system having an encryption device

In radio operation in tactical use, an increased jamming resistance with respect to intentional jamming is required. For protection against intentional jamming, frequency hopping techniques have proven very advantageous in which the signals are transmitted in the form of successive error-protected signal blocks where each signal block is transmitted on a different radio carrier frequency which changes in a pseudo-random manner. With this technique, phase shifts can occur which are greater than half a bit and therefore make analysis of the signal blocks difficult or impossible. It is proposed herein that each received signal block be checked after regeneration in a regenerative repeater, controlled by a bit clock pulse, as to its correct block phase and therefore, respectively, newly establish the block clock pulse phase required for further accurate processing of a signal block.

Method for protected radio signal transmission

A system for encrypted information transmission is disclosed in which so-called recording interference is suppressed. Encryption is effected by means of a periodically recurring pseudo-noise sequence (key word). Synchronization between transmitter and receiver is produced by means of a sync word. During the period of validity of the key word, each sync word is used only once. At least the sync words already used or the information derived therefrom are stored in a sync-word memory (SP). If a sync word appears twice, this indicates recording interference, and the associated information is suppressed.

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Karlsruhe, Germany

Norbert Erbes