Electronics and Telecommunications Research Institute

Duck Gun Park

Sung Weon Kang

Sung Eun Kim

Kyung Soo Kim

Tae Wook Kang

In Gi Lim

Jung Bum Kim

Jung Hwan Hwang

Chang Hee Hyoung

Jin Kyung Kim

Ki Hyuk Park

Jae Hoon Shim

Hyung Il Park

Hyuk Joo Kim

Chang Auck Choi

Hyung Ii Park

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.

Frequency modulating apparatus and transmitting apparatus including the same, and frequency demodulating apparatus and receiving apparatus including the same

Provided are a method and apparatus using a frequency selective baseband. Symbol-error correction modulation and demodulation is performed by generating a plurality of subgroups by dividing 2spread codes or orthogonal codes used for frequency spreading into 2(M&#x3c;N) spread codes or orthogonal codes; selecting (P+L) subgroups; acquiring P spread codes by inputting M data bits to each of the selected P subgroups to select one spread code among the 2spread codes of each subgroup; generating L*M parity bits for symbol error correction using P*M data bits inputted to the selected P subgroups; selecting one spread code among the 2spread codes of the L subgroups by inputting the L*M parity bits to the L subgroups; and selecting the dominant values among the (P+L) spread codes acquired from the (P+L) subgroups to generate transmitting data including the dominant values, where N, M, P, and L are real numbers.

Apparatus and method for symbol error correctable modulation and demodulation using frequency selective baseband

A method and apparatus for communicating a sound wave is provided. The apparatus includes: a sound wave converter converting a sound wave signal transmitted from a counter apparatus through the human body into an electrical signal when the sound wave is transmitted from the counter apparatus through the human body and converting an electrical signal on data to be output to the counter apparatus into a sound wave; a data processor receiving the converted electrical signal from the sound wave converter and transmitting an electrical signal on the data to be output to the sound wave converter when the data to be output exists; and a switch connected between the sound wave converter and the data processor, the switch transmitting the converted electrical signal to the data processor and transmitting the electrical signal on the data to be output to the sound wave converter. Accordingly, it is possible to efficiently transmit a signal with a low loss of sound wave signal. Thus, it is possible to simply construct communication hardware at a low price.

Method and apparatus for communicating sound wave of human body

There are provided a receiver in human body communication system using multiple receivers reducing an error rate of receiver signals by applying a space diversity acquisition-related SIMO technology to a plurality of received data using multiple receivers or receiver electrodes in a human body communication system using a human body as a medium, and of stably transmitting the data for the interference of signals generated by other users or from different electronic devices, and a method for receiving data in the human body communication system. The receiver and the method for receiving data in a human body communication system may be useful to stably transmit/receive data without any reduction of its transmission rate by reducing the distortion in channels and the signal noise which are caused in the use of one receiver.

Receiver and method for receiving data in human body communication system using multiple receivers

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.

TDD communication apparatus and operation method thereof

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&#x3c;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.

Apparatus and method for modulation and demodulation using frequency selective baseband

Provided is to a communication apparatus and method using a human body as a medium, in which secure/normal data signals are transmitted/received to the inside and outside of a human body respectively, through at least two different frequency channels classified according to a predetermined reference value, to thereby efficiently use a frequency based on a physical characteristic of a channel and increase a data transmission rate while maintaining security.

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Daejeon, South Korea

Duck Gun Park