Abstract: A provided a human body sound transmission apparatus includes: a processing unit processing an audio signal of an audio frequency band including data desired to be transmitted, an audio high frequency signal obtained by combining the audio signal and a first high frequency signal, and a second high frequency signal; and a transmission unit receiving a signal obtained by combining the audio high frequency signal and the second high frequency signal from the processing unit and transmitting the received signal by using a human body as a medium, wherein the audio high frequency signal and the second high frequency signal are combined to be transmitted by using the single transmission unit.

Abstract: An electronic apparatus having a control function using human body communication includes: a first control unit reading control data and performing a control to provide the read control data; a first human body communication unit converting the control data into a signal, which is transmittable through human body communication, according to a control signal outputted from the first control unit; an electrode installed in an outer housing of the electronic apparatus and transmitting the signal provided from the first human body communication unit to a user's body which comes into contact with the electronic apparatus; and a first storage unit storing the control data.

Abstract: Disclosed are a crime prevention system using human body communication and a crime prevention method using human body communication capable of actively and effectively preventing a generation of a crime by using human body communication. The crime prevention system using human body communication includes: a monitoring device attached to a monitoring target to sense his physical contact with an observer and providing information obtained by monitoring the monitoring target through human body communication when body contact of the monitoring target with the observer is sensed; and a reception device attached to the observer, receiving the monitoring information through human body communication, and transmitting the monitoring information to a pre-set destination. A criminal act of the monitoring target may be prevented in advance, and when a criminal act is attempted, an observer who may fall a victim of the criminal act can actively cope with the situation.

Abstract: Disclosed is a system for providing multimedia data using human body communication in transportation capable of improving user convenience in transportation and providing various multimedia data. The system for providing multimedia data using human body communication in transportation includes: a multimedia data providing device converting multimedia data into a signal available for human communication and transmitting the converted signal to one or more of conductive units installed within transportation; and a human body communication device receiving the multimedia data through a user's body brought into contact with the one or more conductive units and executing the received multimedia data.

Abstract: Disclosed are a telematics system using human body communication, a portable device having a telematics function using human body communication, and a method for providing a telematics service using human body communication. The telematics system using human body communication includes: a vehicle receiving an authentication key from at least one portable device through human body communication using a human body as a medium, and controlling the opening and closing of a door of the vehicle based on whether or not the received authentication key is valid; and a first portable device transmitting a first authentication key through a user's body in contact with the vehicle.

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: 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: 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: There is provided a frequency selective transmission apparatus.

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 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 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: 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: 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: An adaptive frequency selective baseband communications method using orthogonal codes includes: a communications testing step of performing communications by using one of a plurality of codes each having a different frequency band; a proper code selecting step of selecting a proper code by using a correlation value of a plurality of codes included in test data transmitted in the communications testing step; a communications performing step of performing communications by using the proper code; and a feedback step of newly selecting a proper code by using the correlation value of the plurality of codes included in the test data transmitted in the communications performing step if a pre-set time duration has lapsed or if a reception error of more than a pre-set reference occurs, and performing the communications performing step again, wherein the test data transmitted in the communications testing step and the communications performing step includes a plurality of codes each having a different frequency band.

Abstract: A frequency selective digital transmission apparatus includes: a preamble transmission processing unit generating a preamble for frame synchronization and spreading the generated preamble with a predetermined spreading code; a header transmission processing unit configuring a header including data attribute information and spreading the header with a predetermined spreading code; a data transmission processing unit performing serial-to-parallel conversion on transmission data according to a selected transmission mode and a spreading scheme and spreading the same with a frequency selective spreading code; and a multiplexing unit multiplexing the preamble, the header, and the data which have been spread by the preamble transmission processing unit, the header transmission processing unit and the data transmission processing unit, respectively, and transmitting the same as digital signals.

Abstract: Provided is a driving voltage control module capable of minimizing current consumption and time taken to return from a standby state to a normal state by controlling driving voltages for electronic circuits and systems for communication when a mobile communication transceiving circuit or a communication system is in a standby state in which there is no busy signal. The driving voltage control module includes a regulator for converting an input power voltage into a predetermined level of DC voltage, and supplying the converted DC voltage to an external circuit module as a driving voltage; and a voltage controller for controlling an output voltage level of the regulator, wherein, under control of the voltage controller, a level of the driving voltage is adjusted to be a standby voltage level lower than a turn-on voltage level of a switching device constituting the external circuit module.

Abstract: Provided is a sub-harmonic frequency mixer having a structure in which two terminals of transistors receiving a Radio Frequency (RF) signal and a Local Oscillation (LO) signal are coupled. The frequency mixer is composed of a single-level structure of transistors and thus can be driven at a lower supply voltage compared to a common frequency mixer. A direct-conversion receiver employing such a frequency mixer needs an RF signal and an LO signal sources of single-phase. Therefore, the direct-conversion receiver has an architecture that simplifies a whole RF transceiver circuit and thus can be advantageously applied in implementing SoC (System-on-Chip) for a low power, high integration, low price and subminiature wireless transceiver circuit.

Abstract: The present invention relates to a powerless electronic notepad and a powerless wireless transmission system using the same, and more particularly, to a powerless electronic notepad that stores data recorded on an electronic notepad using piezoelectric elements and transmits the stored data using a passive RFID tag without the use of a power source, and a powerless wireless transmission system using the same.

Abstract: There is provided a low-power relaxation oscillator.