Comtech Ef Data Corporation

Hughes Electronics Corporation

Envistacom, LLC

Kasra Akhavan-Toyserkani

Michael Beeler

David Stuart Kloper

Cris Mamaril

Frank Kelly

Michael Geist

Andrew Ripple

Harold Thomas Cox

Disclosed is a modem system for transmitting and receiving multi-rotational waveforms comprising at least one waveform modulation subsystem, and a demodulation subsystem programmed to receive a second plurality of sequentially modulated communication waveforms.

Multi-rotational waveform utilizing a plurality of transmission waveforms and transmission paths

A method for encryption and decryption synchronization for a communications channel comprising encrypting a communications channel using a data encryption device, the communications channel comprising a data stream having unique information native to the data stream, transmitting the encrypted data stream using a transmitter without applying an additional framing structure or a multiplexing signaling message after the data stream is encrypted such that the encrypted data stream does not require additional bandwidth to support cryptographic synchronization, receiving by a receiver comprising a decryption device, the transmitted encrypted data stream, and identifying the unique information within the transmitted data stream by iteratively decrypting the encrypted data stream using a processor until a cryptographic parameter is found that results in cryptographic synchronization between the encryption and decryption devices based on a priori knowledge of the unique information within the transmitted data stream.

Method and system for self synchronizing cryptographic parameters

A method for encrypting an information carrier comprising generating a sequence of data using a sequence generator, modulating, using a first modulator an output from the sequence generator such that an interference signal results, encoding the interference generator's synchronization information using an encoder, modulating, using a second modulator, the encoded synchronization information such that a synchronization carrier signal results, spreading the synchronization carrier signal using a spreader such that a spread sub-carrier synchronization signal results, and combining the modulated information carrier signal, interference signal, and spread sub-carrier synchronization signal using a signal combiner such that a composite signal results, the interference signal having one or more signal characteristics that results in obfuscation of the information carrier signal when the information carrier signal and interference signal are combined.

Methods and systems for providing interference based physical-layer encryption

A communication apparatus that shares precise return channel uplink timing information includes a common symbol timing reference and one or more control stations that each transmit independent asynchronous DVB data streams which evenly share the common symbol timing. The control stations each include respective delay trackers to determine broadcast transmission delays associated with the particular control station and transmission path. Each broadcast data stream includes the same non real-time frame marker and a transmission delay message particular to the respective control station. A remote receiver receives one of the broadcast streams and timestamps the non real-time frame marker with a local time of receipt. A timing recovery circuit determines an upcoming return channel frame start time by adjusting the local time of receipt by the particular broadcast transmission delay and a unique receiver offset time. A local transmitter subsequently uplinks a TDMA message in a predetermined time-slot after the return channel frame start time. The method for transmitting a frame synchronized message includes receiving a non real-time frame reference marker in a receiver, timestamping the received frame reference marker with a reception time, and subsequently receiving a control node timing differential at the receiver. The local reception time of the non real-time frame marker is corrected to determine the proper return channel frame transmit start time by applying the control node timing differential and the local offset time. Users then uplink a message during an assigned period after the return channel frame transmit start time.

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Rockville, MD, United States of America

Kasra Akhavan-Toyserkani