Yitran Communications Ltd.

Itran Communications Ltd.

Evgeny Bassin

Dan Raphaeli

Oren Kaufman

Boris Zarud

Mordechai Mushkin

Tanya Rosing

A novel and useful acquisition and synchronization mechanism for spread spectrum communication systems whereby a synchronization sequence comprising a plurality of known symbols spaced apart by predefined time delay intervals is transmitted as the start of packet signal. At the transmitter, a synchronization sequence is transmitted at the beginning of each packet. A synchronization sequence is generated which includes a plurality of symbols with predefined time gaps between each of the symbols. Multiple synchronization sequences may be generated wherein each sequence comprises a unique set of time delays or gaps between each of the symbols. Each set of unique time delays or gaps between symbols of a sequence is stored as a synchronization sequence gap template in memory. When required to generate a synchronization sequence, the sequence generator outputs the plurality of synchronization symbols and inserts a specific time delay between each of the symbols in accordance with the contents of the gap template for the particular synchronization sequence.

Method and apparatus for generating a synchronization sequence in a spread spectrum communications transceiver

A novel and useful mechanism for detecting intrusion and jamming attempts by an imposter node. A time window defined as an emergency window is reserved after the end of a packet and before an acknowledgement window. Nodes that detect the presence of an intruder transmit an emergency packet during the emergency time window to inform the receive node that the packet it received was sent from an imposter node. Attempts to jam the transmission of the emergency packet from the victim node to the receive node are detected by listening during the emergency window time period for carrier signal that indicates that an emergency packet is trying to be sent. An emergency packet request message is sent by the receive node in response which causes the victim node to resend the emergency packet.

Mechanism for detecting intrusion and jamming attempts in a shared media based communications network

A novel and useful acquisition and synchronization mechanism for spread spectrum communication systems whereby a synchronization sequence comprising a plurality of known symbols spaced apart by predefined time delay intervals is transmitted as the start of packet signal. At the receiver, the received signal is correlated against the synchronization sequence using the predefined gaps or time delay intervals inserted between the symbols. The received signal is linearly correlated to generate a correlation peak for each symbol received. The expected position of each correlation peak is calculated and compared to the positions of the correlation peaks received. If the number of matches exceeds a threshold, synchronization is declared.

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Beer Sheva, Israel

Evgeny Bassin