Abstract: A method for wireless communication between a node A and a node B provides physical layer security. The node A has disjoint non-empty sets of antennas A1 and A2. The node B has disjoint sets of antennas B1 and B2, where B1 is non-empty. The method involves the steps of transmitting a first pilot signal from B using only B1; receiving the first pilot signal by the node A using A2; performing by A carrier synchronization and channel estimation based on the first pilot signal; transmitting a second pilot signal by the node A using A1; transmitting an information signal by the node A using A2; receiving the second pilot signal by the node B using both B1 and B2; performing by B carrier synchronization based on the second pilot signal; and receiving the information signal by B using both B1 and B2.

Abstract: A communication network may comprise: a first communication node configured for, based on a first association with a vector, encrypting information to be transmitted; a transmitter circuitry configured for transmitting the encrypted information; a receiver circuitry configured for receiving the transmitted encrypted information; a second communication node configured for, based on a second association with the vector, decrypting the received encrypted information. The vector may be a physical-layer feature vector or a common feature vector. The encryption and decryption may be based on linear or nonlinear encryption functions. A nonlinear encryption function may have an output that is based on a singular value decomposition of an input. The encryption and decryption may apply to security over networks, including for wireless communications or biometric templates.

Abstract: A node of a full duplex wireless transmission system may include cancellation signal generation elements. The cancellation signal generation elements may extract a waveform from received signals, for example signals transmitted from the node, and use the waveform to generate a prefilter or cancellation signal to apply to further received signals. The cancellation signal may cancel interference in received signals caused by signals transmitted from the node.

Abstract: A radio interference cancellation device that cancels self-interference from a transmitter to a receiver that includes a 2N-way RF power splitter having an input and 2N outputs, a power combiner having 2N+1 inputs and an output, and 2N adaptively controllable attenuators. Each adaptively controllable attenuator is coupled by cables between a different output of the 2N-way RF power splitter and a different input of the power combiner, each cable having a total length selected to provide a delay equal to a different one of mT(m=1,N) and mT+?(m=1,N), where T is a delay smaller than the inverse of a bandwidth of the transmitter and receiver, and ? is ¼fc, where fc is the carrier frequency of an RF signal transmitted by the transmitter.

Abstract: A full duplex radio includes self-interference cancellation circuitry for reducing self-interference. The self-interference cancellation circuitry may receive analog radio frequency signals that are to be transmitted by an antenna, and downconvert and digitize the signals to provide a digital baseband signal for processing, for example by an adaptive filter. The filtered signal may be converted to an analog signal and applied in an analog portion of a receive chain of a receiver of the full duplex radio. Preferably the analog signal is applied in the receive chain after low noise amplification of received signals of interest.

Abstract: A radio interference cancellation device that cancels self-interference from a transmitter to a receiver that includes a 2N-way RF power splitter having an input and 2N outputs, a power combiner having 2N+1 inputs and an output, and 2N adaptively controllable attenuators. Each adaptively controllable attenuator is coupled by cables between a different output of the 2N-way RF power splitter and a different input of the power combiner, each cable having a total length selected to provide a delay equal to a different one of mT(m=1,N) and mT+?(m=1,N), where T is a delay smaller than the inverse of a bandwidth of the transmitter and receiver, and ? is ¼fc, where fc is the carrier frequency of an RF signal transmitted by the transmitter.

Abstract: A full duplex radio includes self-interference cancellation circuitry for reducing self-interference. The self-interference cancellation circuitry may receive analog radio frequency signals that are to be transmitted by an antenna, and downconvert and digitize the signals to provide a digital baseband signal for processing, for example by an adaptive filter. The filtered signal may be Cconverted to an analog signal and applied in an analog portion of a receive chain of a receiver of the full duplex radio. Preferably the analog signal is applied in the receive chain after low noise amplification of received signals of interest.

Abstract: A node of a full duplex wireless transmission system may include cancellation signal generation elements. The cancellation signal generation elements may extract a waveform from received signals, for example signals transmitted from the node, and use the waveform to generate a prefilter or cancellation signal to apply to further received signals. The cancellation signal may cancel interference in received signals caused by signals transmitted from the node.