A leaky-wave antenna for fluid environments includes a waveguide cavity defined by a waveguide wall. The waveguide cavity is filled with a waveguide fluid. The waveguide walls are made of either an anisotropic material that utilize one of orthotropic stiffness of the anisotropic material to control mode conversion, a band gap material to approximate an acoustically rigid boundary, and a combination of the two materials.

A leaky-wave antenna for fluid environments includes a waveguide cavity defined by a waveguide wall. The waveguide cavity is filled with a waveguide fluid. The waveguide walls are made of either an anisotropic material that utilize one of orthotropic stiffness of the anisotropic material to control mode conversion, a band gap material to approximate an acoustically rigid boundary, and a combination of the two materials.

A method for a mobile network, which mobile network is formed of cells. The method includes determining a weight factor between two cells of the mobile network, which determination of the weight factor includes calculating a distance factor between the cells, calculating an angle factor between the cells, and calculating the weight factor between the cells with an exponential function of the distance factor and the angle factor. The weight factors between the cells may be used for determining network parameters of a mobile network.

A method for a mobile network, which mobile network is formed of cells. The method includes determining a weight factor between two cells of the mobile network, which determination of the weight factor includes calculating a distance factor between the cells, calculating an angle factor between the cells, and calculating the weight factor between the cells with an exponential function of the distance factor and the angle factor. The weight factors between the cells may be used for determining network parameters of a mobile network.

A system for determining the location of a mobile receiver unit includes static transmitter units, each including a respective clock which it uses to transmit a positioning signal according to a respective transmission schedule. The mobile receiver unit receives a positioning signal from any of the static transmitter units. A first processing means uses information relating to the received positioning signal to determine the location of the mobile receiver unit. A second processing means uses information relating to a respective drift and/or offset of each of the clocks of the static transmitter units to generate transmission schedules for the static transmitter units. Each transmission schedule instructs a respective static transmitter unit to transmit a positioning signal at one or more scheduled times according to the clock of the static transmitter unit.

A system for determining the location of a mobile receiver unit includes static transmitter units, each including a respective clock which it uses to transmit a positioning signal according to a respective transmission schedule. The mobile receiver unit receives a positioning signal from any of the static transmitter units. A first processing means uses information relating to the received positioning signal to determine the location of the mobile receiver unit. A second processing means uses information relating to a respective drift and/or offset of each of the clocks of the static transmitter units to generate transmission schedules for the static transmitter units. Each transmission schedule instructs a respective static transmitter unit to transmit a positioning signal at one or more scheduled times according to the clock of the static transmitter unit.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

Aspects of the present disclosure provide a first apparatus configured to transmit a first signal having a first frequency to a second apparatus, receive, from the second apparatus, a second signal having a second frequency responsive to the first signal, determine a latency associated with the transmitted first signal and received second signal and, determine a distance between the first apparatus and the second apparatus based, at least in part, on the determined latencies. According to an example, the first apparatus further determines a direction of the second apparatus relative to the first apparatus. According to an example, at least one of the first signal or second signal comprises an ultrasonic or high-frequency signal.

A wireless positioning system for detecting a positioning coordinate of a person comprises a wireless positioning device for sending a wireless broadcast signal comprising a device identity code and a motion vector; a plurality of wireless base stations for receiving the wireless broadcast signal and sending a positioning signal comprising a wireless broadcast signal and an RSSI; and a positioning server for receiving the positioning signal and calculating the positioning coordinates of the wireless positioning device according to the positioning signal. Wherein, when the received positioning signal is insufficient to calculate the positioning coordinates, the positioning coordinates are calculated based on the last positioning coordinate plus the motion vector. Compared with the prior art, the wireless positioning system of the present invention uses the RSSI to cooperate with the motion vector. The wireless positioning range is expanded with more accuracy.