A hybrid cellular and non-cellular multi-hop communication device, including a hand-held wireless device having one or more antennas, a cellular wireless interface connected to at least some of the one or more antennas, and a non-cellular wireless interface connected to at least some of the one or more antennas. The non-cellular wireless interface may include a rate allocator configured to select a physical-layer rate of transmission of data from the non-cellular wireless interface based on a queue length of data to be transmitted from the hand-held cellular device and a transmitter configured to wirelessly transmit data from the queue and adjust physical-layer transmission parameters based on a physical-layer rate selected by the rate allocator.

The present disclosure discloses a signal sending method and device. The method includes: receiving, by a base station, an uplink pilot signal sent by authorized user equipment, and determining a direction vector parameter and a first channel fading parameter of a channel calculating, according to the direction vector parameter and the first channel fading parameter, a first signal beamformer parameter, determining a transmission area of an artificial noise signal according to the direction vector parameter, and calculating a second signal beamformer parameter; and processing a to-be-transmitted signal by using the first signal beamformer parameter and the second signal beamformer parameter, and transmitting the processed signal. In this way, in a non-target direction, energy leakage of the secrecy signal to the authorized user equipment is relatively small, and transmitted artificial noise signals are concentrated in an area with a relatively high secrecy signal leakage risk.

A base station of a communication system may include an antenna; a memory; and a processor. The processor analyzes a signal received through the antenna to determine if the received signal is a signal transmitted from a fake base station. Based on a determination that the source of the received signal is the fake base station, the processor generates a random access preamble signal for accessing the fake base station. The processor transmits the generated random access preamble signal through the antenna. Thus, the base station may effectively defend against an attack from a fake base station by detecting the fake base station based on collected information of a neighboring base station and causing radio resources of the detected fake base station to be exhausted. Various other embodiments are possible.

An Unmanned Aerial Vehicle is disclosed. The Unmanned Aerial Vehicle includes a body, rotors attached to the body, one or more sensors, and an electromagnetic pulse transmitter. The electromagnetic pulse transmitter is configured to transmit an EMP and the Unmanned Aerial Vehicle is configured to track a target Unmanned Aerial Vehicle using the one or more sensors and direct the electromagnetic pulse transmitter at the target Unmanned Aerial Vehicle to disrupt the target Unmanned Aerial Vehicle.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a base station, a control signal scheduling the UE to receive a downlink message from the base station using a set of time and frequency resources. The UE may identify an aggressor UE attempting to receive uplink communications, downlink communications, or both, transmitted between the UE and the base station and determine a transmit power for transmitting a jamming signal to the aggressor UE during the set of time and frequency resources. The UE may apply a jamming signal power scheme to the jamming signal by either using the determined transmit power or adjusting the determined transmit power in accordance with the jamming signal power scheme.

A method and apparatus for selecting frequency modulated continuous wave waveform parameters for multiple radar coexistence by a user equipment is described. The user equipment may transmit a radar waveform consisting of a number of chirps, with each chirp having a same duration. The user equipment may vary waveform parameters of the radar waveform for at least a subset of the number of chirp, where the waveform parameters may be chosen from a codebook comprising at least one codeword of parameters. Reflected radar waveforms are received and processed where the processing includes applying a fast time discrete Fourier transform to reflected radar waveforms to produce a one dimension peak in a time delay dimension for each reflected waveform; and applying a slow time discrete Fourier transform to the reflected radar waveforms, where peaks for the reflected waveforms are added.

Disclosed is a method of producing an output signal from a signal generator, comprising: determining a driving input to the signal generator, the driving input for driving the signal generator to provide a predetermined output signal, wherein the output signal includes at least one frame, the at least one frame comprising an active period and a dummy period and wherein the active period and dummy period are determined by the driving input. Also disclosed is a method of producing an output signal from a signal generator, comprising: receiving a synchronisation signal; obtaining an input signal for controlling the signal generator to generate an output signal comprising at least one frame wherein the at least one frame comprises at least one active period and at least one dummy period; producing the output signal comprising a series of frames; and, synchronising the output signal with the synchronisation signal by varying a duration of the at least one of the dummy period or active period.

This application relates to an apparatus and method for generating a jamming signal, and a communication system. In one aspect, the method may include converting binary bits of a first communication signal to be transmitted and obtaining at least one codeword matched previously to the binary bits. The method may also include generating a second communication signal by superimposing a first conversion signal being obtained by converting the first communication signal to an up-chirp signal and a second conversion signal being obtained by converting the first communication signal to a down-chirp signal. The method further include generating a pseudo jamming signal by computing the second communication signal and the codeword.

Systems, methods, and apparatus for identifying, tracking, and disrupting UAVs are described herein. Sensor data can be received from one or more portable countermeasure devices or sensors. The sensor data can relate to an object detected proximate to a particular airspace. The system can analyze the sensor data relating to the object to determine a location of the object and determine that the object is flying within the particular airspace based at least in part on location data. A portable countermeasure device can be identified that corresponds to the location of the object. The system can transmit information about the object to the identified portable countermeasure device. The portable countermeasure device can transmit additional data relating to the object to the system.

A portable Electromagnetic Countermeasure (ECM) device is disclosed for military and civilian population protection from electromagnetic communications and attack, including cell phones, radios, radio-triggered explosive devices, and other personal and portable devices comprising transmitters and receivers. The portable ECM device is usable by a person such as a soldier or policeman to protect themselves and other people around them from spy, guerrilla, military and terrorist threats. The portable (ECM) device comprises a first antenna and a second antenna, both to communicate radio signals with a software defined radio (SDR), and a control pack having a microprocessor operable by remote network connection, or by a mode selector on board the device, to control the SDR according to a mode selected, to receive, produce, and classify radio signals.