A software-defined radio system has a plurality of fixed radio receivers each operable to receive radio signals in a receiving band, to sample a received radio signal to produce a sample stream, and to send the sample stream over a network. The radio system includes at least one fixed sync signal transmitter operable to transmit predetermined sync signals in said receiving band to receivers of the aforementioned plurality. The radio system further comprises a data processing system which is connected to the network for receiving sample streams from the receivers. The data processing system is operable to align samples of a data signal contained in sample streams from different receivers by: detecting a sync signal in those sample streams; determining a timing offset between samples of the sync signal in those sample streams in dependence on predetermined locations of the different receivers and the transmitter of that sync signal; and aligning the samples of the data signal in dependence on the timing offset.

A software-defined radio system has a plurality of fixed radio receivers each operable to receive radio signals in a receiving band, to sample a received radio signal to produce a sample stream, and to send the sample stream over a network. The radio system includes at least one fixed sync signal transmitter operable to transmit predetermined sync signals in said receiving band to receivers of the aforementioned plurality. The radio system further comprises a data processing system which is connected to the network for receiving sample streams from the receivers. The data processing system is operable to align samples of a data signal contained in sample streams from different receivers by: detecting a sync signal in those sample streams; determining a timing offset between samples of the sync signal in those sample streams in dependence on predetermined locations of the different receivers and the transmitter of that sync signal; and aligning the samples of the data signal in dependence on the timing offset.

Systems and method are provided for using millimeter-wave radar for terrain-aided navigation in support of autonomous guidance, landing, and mapping functions in all weather for unmanned air vehicles (UAVs). In an embodiment, a UAV can generate a map, based on millimeter-wave (MMW) radar returns, that rejects a large number of radar measurements as clutter and generates a flight path using waypoints based on the map. Embodiments of the present disclosure provide a means of correlating MMW radar returns with high resolution terrain maps to enable navigation in GPS-denied environments. This process significantly reduces cost, development time, and complexity when compared to conventional approaches.

Systems and method are provided for using millimeter-wave radar for terrain-aided navigation in support of autonomous guidance, landing, and mapping functions in all weather for unmanned air vehicles (UAVs). In an embodiment, a UAV can generate a map, based on millimeter-wave (MMW) radar returns, that rejects a large number of radar measurements as clutter and generates a flight path using waypoints based on the map. Embodiments of the present disclosure provide a means of correlating MMW radar returns with high resolution terrain maps to enable navigation in GPS-denied environments. This process significantly reduces cost, development time, and complexity when compared to conventional approaches.

A system for detecting angle-of-arrival (AoA) includes a first device and at least one second device. The first device transmits a Bluetooth (BT) packet, and the second device receives the BT packet and determines an AoA of the BT packet. The second device includes a first radio-frequency (RF) antenna to receive a first RF signal and a second RF antenna to receive a second RF signal. The second device also includes a first BT core and a second BT-core and a processing circuit. The first BT core is coupled to the first RF antenna and is used to generate a first signal based on the first RF signal. The second BT core is coupled to the second RF antenna and generates a second signal based on the second RF signal. The processing circuit measures a phase difference between the first signal and the second signal and determines the AoA based on the phase difference.

A system for detecting angle-of-arrival (AoA) includes a first device and at least one second device. The first device transmits a Bluetooth (BT) packet, and the second device receives the BT packet and determines an AoA of the BT packet. The second device includes a first radio-frequency (RF) antenna to receive a first RF signal and a second RF antenna to receive a second RF signal. The second device also includes a first BT core and a second BT-core and a processing circuit. The first BT core is coupled to the first RF antenna and is used to generate a first signal based on the first RF signal. The second BT core is coupled to the second RF antenna and generates a second signal based on the second RF signal. The processing circuit measures a phase difference between the first signal and the second signal and determines the AoA based on the phase difference.

Drone-based wireless communications systems are provided, as are methods carried-out by such wireless communications systems. In one embodiment, the wireless communications system includes a Satellite Signal Transformation (SST) unit and a plurality of aerial network drones, which can be deployed over a designated geographical area to form a multi-drone network thereover. During operation, the SST unit transmits a network source signal, which contains content extracted from a satellite signal. The multi-drone network receives the network source signal, disseminates drone relay signals containing the content through the multi-drone network, and broadcastings user device signals containing the content over the designated geographical area. In embodiments, the multi-drone network may broadcast multiple different types of user device signals for reception by various different types of user devices located within the designated geographical area, such as an arear containing communication infrastructure disabled by a natural disaster, a hostile attack, or other catastrophic event.

Drone-based wireless communications systems are provided, as are methods carried-out by such wireless communications systems. In one embodiment, the wireless communications system includes a Satellite Signal Transformation (SST) unit and a plurality of aerial network drones, which can be deployed over a designated geographical area to form a multi-drone network thereover. During operation, the SST unit transmits a network source signal, which contains content extracted from a satellite signal. The multi-drone network receives the network source signal, disseminates drone relay signals containing the content through the multi-drone network, and broadcastings user device signals containing the content over the designated geographical area. In embodiments, the multi-drone network may broadcast multiple different types of user device signals for reception by various different types of user devices located within the designated geographical area, such as an arear containing communication infrastructure disabled by a natural disaster, a hostile attack, or other catastrophic event.

A positioning apparatus (100) includes a temporary position computation unit (120), a two-dimensional position computation unit (140), a three-dimensional position computation unit (150), and a position aggregation unit (160), and executes three-dimensional positioning of a terminal using a relative angle formed by each base station and the terminal. The temporary position computation unit (120) computes a temporary position of the terminal based on observation data. The two-dimensional position computation unit (140) computes a two-dimensional position of the terminal based on the observation data and the temporary position. The three-dimensional position computation unit (150) computes a three-dimensional position of the terminal based on the observation data and the temporary position. The position aggregation unit (160) determines the position of the terminal by aggregating the two-dimensional position and the three-dimensional position.

A positioning apparatus (100) includes a temporary position computation unit (120), a two-dimensional position computation unit (140), a three-dimensional position computation unit (150), and a position aggregation unit (160), and executes three-dimensional positioning of a terminal using a relative angle formed by each base station and the terminal. The temporary position computation unit (120) computes a temporary position of the terminal based on observation data. The two-dimensional position computation unit (140) computes a two-dimensional position of the terminal based on the observation data and the temporary position. The three-dimensional position computation unit (150) computes a three-dimensional position of the terminal based on the observation data and the temporary position. The position aggregation unit (160) determines the position of the terminal by aggregating the two-dimensional position and the three-dimensional position.