Abstract: A walking guidance apparatus using human body communication, including: a first human body communication device acquiring a walking guidance information signal, converting the acquired walking guidance information signal into a signal available for human body communication, and transmitting the converted signal through a user's body; and a second human body communication device receiving the signal transmitted through the user's body from the first human body communication device, converting the received signal into a signal that can be recognized by the user, and outputting the converted signal. Walking guidance information having a high privacy function and high stability and accuracy can be provided to enhance user convenience.

Abstract: Disclosed are an authentication apparatus using human body communication capable of improving the security and convenience of user authentication by using human body communication, a portable device having authentication function using human body communication, and an authentication method using human body communication. In the authentication method using human body communication, an authentication device acquires user biometric information and provides the acquired biometric information to a portable device by using human body communication. The portable device then compares the acquired biometric information with previously stored biometric information, and when the acquired biometric information and the previously stored biometric information are identical, the portable provides authentication information to the authentication device. Upon receiving the authentication information, the authentication device performs an authentication procedure based on the authentication information.

Abstract: Provided are modulation and demodulation methods and apparatuses using a frequency selective baseband. The frequency modulation method includes: generating a plurality of subgroups by dividing 2N (N is a real number) spread codes used for frequency spreading into 2M (M<N, M is a real number) spread codes; selecting P(P is a real number) subgroups among the generated subgroups; acquiring P spread codes by inputting M data bits to each of the p subgroups so as for 1 spread code to be selected among the 2M spread codes of each subgroup; and selecting dominant value among the acquired P spread codes to generate transmitting data including the dominant value. Accordingly, it is possible to increase a processing gain of the entire system, to increase a transmission data rate, and to reduce power consumption of the system.

Abstract: Provided is a single sound transmission apparatus using human body communication. The single sound transmission apparatus includes a sound signal generator generating a sound signal of an audio frequency band, a high frequency signal generator generating a high frequency signal having a higher frequency than the audio frequency band, a signal combiner generating a combined signal by combining the sound signal with the high frequency signal, and a signal transmitter varying a phase difference between the combined signal outputted from the signal combiner and the high frequency signal outputted from the high frequency signal generator, and outputting the combined signal and the high frequency signal together to a human body, in order to leave only the sound signal through destructive interference of the high frequency signal of the combined signal, wherein the destructive interference is generated in an ear area of the human body.

Abstract: A method for generating a communication frame of a body area network, includes: recognizing the number of terminals existing within a predetermined area; allocating an individual frame to be used by each of the terminals existing within the predetermined area according to the recognized number of terminals; and allocating a coexistence frame to be transmitted to every terminal existing within the predetermined area according to the recognized number of terminals.

Abstract: A communication apparatus using a synchronized clock signal includes: a communication signal generation unit generating one of a baseband signal and a signal obtained by applying digital modulation to the baseband signal, as a communication signal; an interface unit transmitting the generated communication signal and receiving a communication signal from an external source; a communication signal analyzing unit analyzing the received communication signal; a clock signal providing unit providing a clock signal to the communication signal generation unit, the interface unit, and the communication signal analyzing unit; and a controller controlling the communication signal generation unit, the interface unit, the communication signal analyzing unit, and the clock signal providing unit.

Abstract: There is provided a frequency selective transmission apparatus.

Abstract: A communications device using a near field includes: a near field signal providing unit providing one of a baseband signal and a signal obtained by applying digital modulation to the baseband signal, as a near field signal; an interface unit transmitting and receiving the provided near field signal; and a controller controlling the near field signal providing unit and the interface unit. A low data transfer rate of the related art near field communications can be overcome. Namely, various services can be provided by using a high data transfer rate. In particular, near field communications and a network configuration and data communications performed through the existing wireless network can be implemented as a single combined technique. In addition, power supply and communications can be simultaneously provided effectively by sharing an interface of an electrical coupling and a magnetic coupling.

Abstract: A preamble generating apparatus and method for a digital direct transmission system are disclosed. The preamble generating apparatus for a digital direct transmission system includes: a pseudo-noise (PN) code generation unit generating a PN code; a line coder performing line coding on the PN code received from the PN code generation unit; and a spreading coder performing spread coding on the line-coded PN code received from the line coder.

Abstract: A frequency selective modulation apparatus and method using re-spreading codes are disclosed. The frequency selective modulation apparatus includes: a serial-to-parallel converter receiving transmission data and performing serial-to-parallel conversion on the transmission data at a pre-set ratio; one or more sub-frequency selective spreaders selecting one spreading code by using data bits received from the serial-to-parallel converter; a majority value selection unit selecting a majority value from one or more spreading codes which have been selected by each of the one or more of the sub-frequency selective spreaders; and a first XOR logic circuit XORing an output of the majority value selection unit and a re-spreading code Wn to re-spread a frequency selective baseband to a frequency selective passband.

Abstract: There is provided a system and a method for measuring phase response characteristic of a human body in human-body communication. The system and method may be useful to measure phase response characteristic of the human body without forming a common ground line between a reference signal transmitter and a reference signal receiver by transmitting a first reference signal through the human body and transmitting a second reference signal through the optical cable.

Abstract: A human body sound transmission apparatus and method for minimizing a signal loss are disclosed. The human body sound transmission apparatus includes: an audio signal transmission unit modulating an audio signal desired to be transmitted, and transmitting the modulated audio signal to the vicinity of a user's ear through the human body (i.e., a user's body); and a carrier wave signal transmission unit transmitting a carrier wave signal for demodulating the modulated audio signal to the vicinity of the user's ear through the air.

Abstract: Provided are symbol-error-correctable modulation and demodulation methods and apparatuses using a frequency selective baseband.

Abstract: There are provided a human body sound transmission system and a method. The human body sound transmission system according to an aspect of the present invention directly or indirectly contacts a human body to apply coupled signals of high frequency sound signals with high frequency signals, which recover sound signals from the high frequency sound signals, to the human body and transmit the sound signals using the human body as a transmission medium, wherein a magnitude of the sound signals recovered around a human's ear is increased in proportion to the number of signals transmitted through the human body by transmitting the plurality of signals including the same sound signals through the human body.

Abstract: Provided are a human body communication apparatus for non-contact communications using a frequency-selective baseband and a human body communication method for non-contact communications in the same. The human body communication apparatus may be useful to perform stable communications between users by reducing interference induced from other communication apparatuses without affecting interference between the users since data are transmitted/received between communication apparatuses adjacent to a human body by spreading and despreading the data using only spreading codes of a limited frequency band (frequency-selective baseband) in which an inductive electromagnetic field formed by an antenna shows the most effective characteristics.

Abstract: A Time Division Duplex (TDD) communication apparatus and an operation method thereof can provide operation clock signals in the transmission and reception of the TDD communication apparatus using a Clock Recovery & Data Retiming (CDR) circuit, thereby stabilizing an operation without any crystal oscillator and reducing the power consumption. In a transmission time interval, a transmitting frame is processed using a clock signal of a reference frequency generated from the CDR circuit. In a reception time interval, a receiving frame is processed using a clock signal recovered from the receiving frame by the CDR circuit.

Abstract: Provided are a frequency modulation/demodulation apparatus using a frequency selective baseband and a transmitting/receiving apparatus using the same. In a frequency selective baseband transmission technique or an FS-CDMA technique, a transmission rate is controlled according to communication channel environment, spread code groups are repeatedly selected in a receiving side so as to obtain a frequency diversity gain. Accordingly, it is possible to reduce interference between users. In addition, even in a case where strong interference induced from electronic exists, it is possible to implement low-power, stable human-body communication and to ensure a communication quality.

Abstract: A training apparatus based on motion content includes a plurality of motion detecting sensors (11 a . . . 11 n) dispersedly arranged in a body of a user to obtain position information signals of respective body parts of the user, a motion controller (20) analyzing the position information signals to detect a user motion, and comparing the detected motion with a reference motion provided from motion contents to generate a motion calibration signal for training of a motion calibration, and a plurality of motion calibrating sensors (12a . . . 12n) dispersedly arranged in the body to stimulate the body part of the user according to the motion calibration signal and calibrate the user motion, and consequently can provide a training service for continual motions and increase a motion calibration effect.

Abstract: There is provided a human body communication method and system using a frequency-selective baseband in order to transmit and receive data between communication devices that are coupled to a human body by using the human body as a communication channel. The human body communication method and system may be useful to maximize an efficiency of the frequency-selective spreading technology to enhance a processing gain of the Walsh code technology, and thus to reduce the interference between human bodies of users by adaptively selecting a frequency band of Walsh codes that are used for data communications according to the human body channel characteristics and the noise environments that are varied according to the ambient environments, and also construct a low-power and stable human body communication when there is a strong interference induced from other electronic equipments.

Abstract: A human body communication apparatus, a human body communication system, and a method using the same are provided. The communication apparatus is directly in contact with a human body and allows a small amount of current including a data signal to flow through the body so that information is communicated through the human body. In order to efficiently perform a data communication by preventing a collision of data packets in the human body communication system, one communication apparatus is selected from a plurality of communication apparatuses configuring the human body communication system to control or manage a communication order for other communication apparatuses and the respective apparatuses check whether the respective communication apparatuses transmit data through the human body to try a communication.