Abstract: The present invention relates to an underwater communication method capable of communicating with a plurality of sensor nodes within a limited frequency band. Underwater information communication of the present invention allocates an appropriate frequency to each sensor node according to the distance between a central node and the plurality of sensor nodes, and then, controls underwater communication between the central node and the plurality of sensor nodes using the allocated frequency. By virtue of such control, the present invention prevents the occurrence of an unusable sensor node which cannot smoothly perform underwater communication when the allocated frequency is unreasonable. Therefore, the present invention has the effect of enabling efficient underwater communication between a plurality of sensor nodes and a central node.

Abstract: A communication system for underwater lifesaving and a method for locating a person immersed in water. The communication system for underwater lifesaving includes: a water immersion signal generation unit that is worn on the body of a user, detects whether the user is immersed in water, and generates a water immersion detection signal corresponding to the user when water immersion is detected; and a water immersion signal reception unit that receives a water immersion detection signal generated by the water immersion signal generation unit and analyzes the location of the user in response to a water immersion detection signal being received.

Abstract: A communication system for underwater lifesaving and a method for locating a person immersed in water. The communication system for underwater lifesaving includes: a water immersion signal generation unit that is worn on the body of a user, detects whether the user is immersed in water, and generates a water immersion detection signal corresponding to the user when water immersion is detected; and a water immersion signal reception unit that receives a water immersion detection signal generated by the water immersion signal generation unit and analyzes the location of the user in response to a water immersion detection signal being received.

Abstract: The present invention relates to underwater communication and, more particularly to a signal transmission method and device which configure and transmit physical channel information such that low-power control is performed in underwater communication. The present invention configures the physical channel information such that a reception node side can check through a combination of preambles whether a signal is provided to itself, when forward direction communication is performed in a centralized underwater communication network. Therefore, the present invention performs the control such that only a relevant reception node requiring data reception performs a demodulation operation, without requiring all reception nodes to always perform demodulation in a forward direction communication process. Through this process, many reception nodes do not perform unnecessary demodulation operations in the forward direction communication process, thereby providing an effect of preventing unnecessary power consumption.

Abstract: The present invention relates to underwater communication and, more particularly to a signal transmission method and device which configure and transmit physical channel information such that low-power control is performed in underwater communication. The present invention configures the physical channel information such that a reception node side can check through a combination of preambles whether a signal is provided to itself, when forward direction communication is performed in a centralized underwater communication network. Therefore, the present invention performs the control such that only a relevant reception node requiring data reception performs a demodulation operation, without requiring all reception nodes to always perform demodulation in a forward direction communication process. Through this process, many reception nodes do not perform unnecessary demodulation operations in the forward direction communication process, thereby providing an effect of preventing unnecessary power consumption.

Abstract: The present invention provides an underwater communication system capable of efficiently communicating with a plurality of sensor nodes by using a limited frequency in the water. The present invention has a hierarchical structure in which one underwater base station control station manages a plurality of underwater base stations in the water, and each underwater base station within a plurality of underwater base stations centrally manages a plurality of underwater sensor nodes. Furthermore, the present invention enables efficient underwater communication the underwater environment by using different frequencies, when the underwater base station control station performs the underwater communication with the plurality of underwater base stations, and when the underwater base stations perform the underwater communication with the plurality of underwater sensor nodes.

Abstract: The present invention provides an underwater communication system capable of efficiently communicating with a plurality of sensor nodes by using a limited frequency in the water. The present invention has a hierarchical structure in which one underwater base station control station manages a plurality of underwater base stations in the water, and each underwater base station within a plurality of underwater base stations centrally manages a plurality of underwater sensor nodes. Furthermore, the present invention enables efficient underwater communication the underwater environment by using different frequencies, when the underwater base station control station performs the underwater communication with the plurality of underwater base stations, and when the underwater base stations perform the underwater communication with the plurality of underwater sensor nodes.

Abstract: The present invention relates to an underwater communication method capable of communicating with a plurality of sensor nodes within a limited frequency band. Underwater information communication of the present invention allocates an appropriate frequency to each sensor node according to the distance between a central node and the plurality of sensor nodes, and then, controls underwater communication between the central node and the plurality of sensor nodes using the allocated frequency. By virtue of such control, the present invention prevents the occurrence of an unusable sensor node which cannot smoothly perform underwater communication when the allocated frequency is unreasonable. Therefore, the present invention has the effect of enabling efficient underwater communication between a plurality of sensor nodes and a central node.

Abstract: Provided are wireless communication methods. The wireless communication method receives communication information through a plurality of antennas, generates a plurality of beam directions, selects one of the beam directions on the basis of the received communication information, and performs communication using the selected beam direction. Communication information received through the unselected beam directions among the beam directions are ignored.

Abstract: An OFDM receiving device for adjusting a beam formation azimuth through a plurality of antennas, a communication device using the same, and a method thereof.

Abstract: An OFDM receiving device for adjusting a beam formation azimuth through a plurality of antennas, a communication device using the same, and a method thereof.