Abstract: A communication device and method using the human body are provided. The communication device determines an arrangement direction of signal electrodes and ground electrodes according to a signal transmission direction and whether the ground electrodes come into contact with the human body according to a transmission/receiving distance and then performs data communication with the other communication device connected to the human body for the purpose of efficient human body communication.

Abstract: Provided is a human body communication method using a multi-carrier modulation method, in which users do not interfere with each other in an environment with several users, and stable communication is possible when users are exposed to strong interference generated at other electronic devices. Also, provided are a multi-carrier modulation method, in which data between communication devices connected to a human body used as a channel is divided into a plurality of sub-channels and the data is transmitted by loading it on each of a plurality of sub-carrier signals, and a multi-connection method using the multi-carrier modulation method. The plurality of sub-channels having a predetermined bandwidth include several sub-carriers, and by changing a modulation method applied to the sub-carriers, stable communication can be realized.

Abstract: Provided are a method, apparatus and system for providing a touch and play (TAP)-based service.

Abstract: Provided is a communication apparatus having a human body contact sensing function and a method thereof. The communication apparatus includes: an electrode that comes in contact with the human body; a contact sensor that is connected to the electrode, and instructs the central processing unit to perform an initial operation if contact with the human body is sensed; and a data processing unit that receives a control signal from the central processing unit so as to select whether to transmit or receive data, and performs a transmitting or receiving operation according to the control signal. Accordingly, in order to reduce power consumption when in a stand-by state before human body contact is made in a communication apparatus using a human body as a communication medium, a human body contact sensor is included so as to minimize power consumption of a micro processing unit and a transmitter/receiver circuit until contact occurs.

Abstract: The present invention provides a communication apparatus being in directly contact with a human body and using the human body as a transmission channel for data communication. The communication apparatus attached to the human body transmits a signal in the form of a current, receives a signal transmitted from another communication apparatus attached to the human body therethrough, and eliminates noise included in the received signal. In addition, the communication apparatus compares the noise-eliminated signal and a reference signal and recovers an original signal. Further, the communication apparatus generates a base-band signal and transmits the same through the human body.

Abstract: A communication system using a frequency determined according to information security protection or a transmission distance of a signal is provided. A local area communication requiring information security protection uses a frequency less than a predetermined frequency, and a local or wide area communication requiring no information security protection uses a frequency greater than predetermined frequency, thereby providing an effective communication environment based on information security protection, a communication distance, and communication characteristics satisfying frequency characteristics of a transmission medium, and accordingly increasing a communication field.

Abstract: Provided is a T-DMB receiver and receiving method using a human body as an antenna. The T-DMB receiver includes: an electrode making contact with a human body; a low frequency amplifier receiving via the electrode a current flowing through the human body due to a DMB broadcasting signal emitted by a terrestrial relay station and amplifying the received current; and an impedance matching circuit located between the electrode and the low frequency amplifier and matching an impedance of the human body with an impedance of the low frequency amplifier. Accordingly, a T-DMB receiver easy to carry without a separate antenna can be implemented.

Abstract: Provided is a dual antenna diversity transmitter and system having improved power amplifier efficiency, and further comprising switches in the dual antenna diversity transmitter and system, to minimize a DC input power consumed by the power amplifier depending on the required transmitting output power and operate efficiently the power amplifier, whereby signal linearity can be maintained and the power amplifier can be efficiently operated in a more simplified manner, as compared to the conventional high efficiency power amplifier.

Abstract: The present invention relates to a sound transmission system using a human body as a propagation medium. The transmission system includes a first signal transmitter and a second signal transmitter respectively generating signals having frequencies corresponding to each other, the first and second signal transmitters being coupled to the human body, wherein the first and second signal transmitters respectively generate high frequency signals having an opposite phase to each other, and the respective signal transmitters combine the audio signals and the high frequency signals to transmit the combined signals to the human body. The respective signal transmitters combine the generated audio signals and high frequency signals, adjust an output phase of the combined signals, and transmit the combined signals through the human body.

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.

Abstract: Provided is communication apparatus and method using a transmission medium, in an environment where at least one transmitter and at least one receiver are connected to at least one human body which is a conductive transmission medium, in which the receiver requiring any information data requests a transmission to the transmitter or the transmitter sends a signal indicative of a transmission of required information data, and then, the transmitter provides the required information data to the receiver requiring the corresponding information data, thereby providing a communication environment without interference between the transmission means and the receiving means.

Abstract: The present invention relates to a variable gain amplifier for a high frequency band, and comprises a divider for dividing a input signal; a fixed variable gain amplifier for amplifying an output signal of the divider; a microstrip ring hybrid for outputting a plurality of signals which have the same or different phases, wherein the microstrip ring hybrid comprises a plurality of input terminals and output terminals having a constant impedance; a switch for selectively inputting an output of the variable gain amplifier to any one of the input terminals of the microstrip ring hybrid; a transmission line for delaying the output signal of the divider; and a combiner for combining each of the output signals of the microstrip ring hybrid and a signal passing through the transmission line and outputting the combined signal, wherein the output power is controlled by selectively inputting the output of the variable gain amplifier to any one of the input terminals of the microstrip ring hybrid by means of the switches

Abstract: The present invention relates to a variable gain amplifier for a high frequency band, and comprises a divider for dividing a input signal; a fixed variable gain amplifier for amplifying an output signal of the divider; a microstrip ring hybrid for outputting a plurality of signals which have the same or different phases, wherein the microstrip ring hybrid comprises a plurality of input terminals and output terminals having a constant impedance; a switch for selectively inputting an output of the variable gain amplifier to any one of the input terminals of the microstrip ring hybrid; a transmission line for delaying the output signal of the divider; and a combiner for combining each of the output signals of the microstrip ring hybrid and a signal passing through the transmission line and outputting the combined signal, wherein the output power is controlled by selectively inputting the output of the variable gain amplifier to any one of the input terminals of the microstrip ring hybrid by means of the switches