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: The present invention relates to a method and a system for recognition of objects near a ship by using a deep neural network to prevent a collision with the object by recognizing a neighboring object that may be risky to the ship sailing in a restricted condition such as a foggy environment. All object movements within a predetermined radius are detected and recognized so that collision accidents with objects on the sea in an environment such as fog caused by bad weather at sea can be prevented, and a risk alarm is notified to a captain when the object is detected so that collision accidents can be remarkably reduced. In addition, peripheral environments are detected by only installing a CCTV camera so that expenses can be reduced, human negligence can be prevented, and the system can be easily constructed to prevent collisions.

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 user authentication, and more particularly, to a method and an apparatus for providing authentication using voice and facial data, in which a voice and a face of a user are recognized and authenticated using an deep learning model, so that theft due to leakage of a password of a security device is prevented from occurring.

Abstract: The present invention relates to user authentication, and more particularly, to a method and an apparatus for providing authentication using voice and facial data, in which a voice and a face of a user are recognized and authenticated using an deep learning model, so that theft due to leakage of a password of a security device is prevented from occurring.

Abstract: The present invention relates to a method and a system for recognition of objects near a ship by using a deep neural network to prevent a collision with the object by recognizing a neighboring object that may be risky to the ship sailing in a restricted condition such as a foggy environment. All object movements within a predetermined radius are detected and recognized so that collision accidents with objects on the sea in an environment such as fog caused by bad weather at sea can be prevented, and a risk alarm is notified to a captain when the object is detected so that collision accidents can be remarkably reduced. In addition, peripheral environments are detected by only installing a CCTV camera so that expenses can be reduced, human negligence can be prevented, and the system can be easily constructed to prevent collisions.

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: A method and an apparatus for generating soft-decision information in a multiple antenna system are provided. The method includes determining Q candidate symbol vectors for a first transmission symbol of a received signal vector by performing parallel detection on a received signal vector and a channel matrix, determining a candidate symbol vector having a shortest Euclidean distance to the received signal vector from among the Q candidate symbol vector, as an approximate Maximum Likelihood (ML) symbol vector, determining (Q?1) candidate symbol vectors for each of the remaining transmission symbols of the received signal vector by performing partial parallel detection on the received signal vector and the channel matrix using the approximate ML symbol vector, and calculating Log Likelihood Ratios (LLRs) of bits of the first transmission symbol using the candidate symbol vectors, wherein Q represents a modulation order.

Abstract: Disclosed are an apparatus and a method for detecting signals in a spatial multiplexing system. An embodiment of the invention provides a signal detection apparatus for a single receiver unit equipped with a plurality of antennas in a system having at least one transmitter unit configured to transmit data streams by spatial multiplexing, where the signal detection apparatus includes: a partial linear coefficient generator unit configured to generate a linear weighting matrix by using a preset algorithm on a channel matrix formed between the transmitter unit and the single receiver unit; a partial symbol remover unit configured to generate a first symbol vector by removing all transmittable symbols for each transmitting antenna from all received data streams; and a partial symbol detector unit configured to generate a transmission symbol candidate vector by using the linear weighting matrix and the first symbol vector.

Abstract: A method and an apparatus for generating soft-decision information in a multiple antenna system are provided. The method includes determining Q candidate symbol vectors for a first transmission symbol of a received signal vector by performing parallel detection on a received signal vector and a channel matrix, determining a candidate symbol vector having a shortest Euclidean distance to the received signal vector from among the Q candidate symbol vector, as an approximate Maximum Likelihood (ML) symbol vector, determining (Q?1) candidate symbol vectors for each of the remaining transmission symbols of the received signal vector by performing partial parallel detection on the received signal vector and the channel matrix using the approximate ML symbol vector, and calculating Log Likelihood Ratios (LLRs) of bits of the first transmission symbol using the candidate symbol vectors, wherein Q represents a modulation order.

Abstract: An apparatus and method for receiving signals in a multiple-input, multiple-output (MIMO) wireless communication system is provided. A receiving end using as many as N Receive (Rx) antennas includes a first detector, as many as (N?2) nth detectors, and an Nth detector. A signal detection technique of the present invention has a low complexity and a throughput similar to that of a Maximum Likelihood (ML) scheme in a Multiple-Input Multiple-Output (MIMO) wireless communication system using a Spatial Multiplexing (SM) scheme.

Abstract: Disclosed are an apparatus and a method for detecting signals in a spatial multiplexing system. An embodiment of the invention provides a signal detection apparatus for a single receiver unit equipped with a plurality of antennas in a system having at least one transmitter unit configured to transmit data streams by spatial multiplexing, where the signal detection apparatus includes: a partial linear coefficient generator unit configured to generate a linear weighting matrix by using a preset algorithm on a channel matrix formed between the transmitter unit and the single receiver unit; a partial symbol remover unit configured to generate a first symbol vector by removing all transmittable symbols for each transmitting antenna from all received data streams; and a partial symbol detector unit configured to generate a transmission symbol candidate vector by using the linear weighting matrix and the first symbol vector.

Abstract: A method and an apparatus for detecting a signal in a multi-antenna system using a spatial multiplexing are provided. The apparatus includes at least one antenna for receiving a signal, a channel estimator for estimating a channel using the received signal, a detector for calculating multiplication values commonly used to determine a Euclidean distance using the receive signal and channel information and for detecting a transmitted signal by calculating Euclidean distances of one or more candidate symbols using the receive signal and the determined multiplication values and a decoder for demodulating and decoding the detected signal. Hence, the computational complexity of the signal detection can be mitigated.

Abstract: Receiving apparatus and method in a Multiple-Input Multiple-Output (MIMO) wireless communication system are provided. The receiver having N-ary receive antennas includes a decomposer for decomposing a channel matrix to a matrix Q and a matrix R through a QR decomposition; a detector for determining a candidate group of an n-th phase by estimating a plurality of transmit signal vectors by substituting a plurality of transmittable symbols into symbol combinations of a candidate group of a (n?1)-th phase as an n-th symbol and detecting (n+1)-th through N-th symbols using characteristics of the matrix R; a calculator for calculating square Euclidean distance values between the transmit signal vectors and a receive signal vector; and a determiner for determining the candidate group of the n-th phase by selecting transmit signal vectors having the smallest square Euclidean distance value among the transmit signal vectors.

Abstract: A method and an apparatus for detecting a signal in a multi-antenna system using a spatial multiplexing are provided. The apparatus includes at least one antenna for receiving a signal, a channel estimator for estimating a channel using the received signal, a detector for calculating multiplication values commonly used to determine a Euclidean distance using the receive signal and channel information and for detecting a transmitted signal by calculating Euclidean distances of one or more candidate symbols using the receive signal and the determined multiplication values and a decoder for demodulating and decoding the detected signal. Hence, the computational complexity of the signal detection can be mitigated.