摘要:
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
摘要:
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.
摘要:
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
摘要:
There is provided a human body communication system including: a wireless capsule injected into the body to acquire image information of the interior of the body and transmitting a signal with respect to the acquired information to the outside of the body from the inside of the body by using an electrode; and a portable data recorder performing, from the outside of the body, RF communication with the wireless capsule by the medium of the body, receiving the signal transmitted from the wireless capsule through an electrode in contact with the human body, processing the received signal into RF data, and storing the RF data.
摘要:
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.
摘要:
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.
摘要:
There is provided a communication method using a human body as a medium. A modulation apparatus using a frequency selective baseband according to an aspect of the invention may include: a serial-to-parallel conversion unit converting serial data supplied from an upper layer into parallel data consisting of M+1 number of data input bits; and a frequency selective spreader selecting one subgroup among a plurality of subgroups obtained by dividing 2N number (where N is a positive integer) of spreading codes used for frequency spreading by 2M (where M is a positive integer, and M
摘要:
There is provided a communication method using a human body as a medium. A modulation apparatus using a frequency selective baseband according to an aspect of the invention may include: a serial-to-parallel conversion unit converting serial data supplied from an upper layer into parallel data consisting of M+1 number of data input bits; and a frequency selective spreader selecting one subgroup among a plurality of subgroups obtained by dividing 2N number (where N is a positive integer) of spreading codes used for frequency spreading by 2M (where M is a positive integer, and M
摘要:
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.
摘要:
Provided are an apparatus and method for transmitting sound through a nonlinear medium. The apparatus includes a pre-distorter for previously distorting a sound signal to compensate for distortion to be caused by a frequency characteristic of the nonlinear medium in a transmission process of the sound signal, a sigma-delta modulator for modulating the pre-distorted sound signal into a signal having two signal levels, a high-frequency modulator for multiplying the modulated signal by a carrier wave having a higher frequency than an audio frequency band to shift the modulated signal to a carrier frequency band and generate a high-frequency modulated signal, and a transmitter for converting the high-frequency modulated signal into a sound wave signal suited to be transmitted through the nonlinear medium and transmitting the sound wave signal.