Abstract:
A communication method for a transmitter using a preamble in a wireless communication system comprises the steps of: determining two or more subcarriers from among a plurality of subcarriers for the preamble; mapping a subcarrier sequence of the preamble and a subcarrier phase value to the two or more subcarriers; and transmitting the preamble using the two or more subcarriers. Here, the preamble comprises a mistake element including a first repetitive pattern, and an imaginary element including a second repetitive pattern, which are within a preset time period of a time domain; and the relationship between the first repetitive pattern and the second repetitive pattern shows the characteristic information of the wireless communication system.
Abstract:
Provided is a method for selecting an antenna performed by a receiver in a multi-antenna system. The method for selecting the antenna performed by the receiver in the multi-antenna system, comprises: a subcarrier group setting step for setting subcarrier groups by grouping subcarriers; a channel information acquisition step for acquiring channel information between a receiving end antenna and each of a plurality of transmission end antennas; an antenna selecting step for determining said subcarrier groups, which are to be transmitted to each of the plurality of said transmission end antennas on the basis of said channel information; and an antenna selection information transmission step for transmitting antenna selection information, which contains the result of said antenna selection, to a transmission end.
Abstract:
Provided is an apparatus for controlling subcarrier spacing in a system supporting multiple frequency bands. The apparatus for controlling a subcarrier spacing comprises: an interference detection unit detecting interference over multiple frequency bands; a system parameter provision unit providing system parameters related to a subcarrier spacing between the multiple frequency bands - for example RF, FFT size, and channel bandwidth; a subcarrier spacing control unit controlling the subcarrier spacing such that the detected interference is reduced, on the basis of the system parameters. In a system operating with multiple bands, different subcarrier spacing can be applied by each band, thereby controlling interference occurring in each band.
Abstract:
A communication method for a transmitter using a preamble in a wireless communication system comprises the steps of: determining two or more subcarriers from among a plurality of subcarriers for the preamble; mapping a subcarrier sequence of the preamble and a subcarrier phase value to the two or more subcarriers; and transmitting the preamble using the two or more subcarriers. Here, the preamble comprises a mistake element including a first repetitive pattern, and an imaginary element including a second repetitive pattern, which are within a preset time period of a time domain; and the relationship between the first repetitive pattern and the second repetitive pattern shows the characteristic information of the wireless communication system.
Abstract:
The present invention relates to a method for shortening an average time applied when an influence of electromagnetic waves of a base station on a human body is evaluated around a mobile communication base station. The invention compares uncertainty caused by repeated measurements with the result of on-the-spot measurements by targeting a plurality of base stations, performs measurements for six minutes at a random measurement point for obtaining a whole-body average, and considers that a shorter measurement time would be sufficient rather than the six minutes if a standard deviation is less than or equal to a certain level, for example, 0.4 dB when a six-minute average value is compared with an average value of a shorter time other than six minutes.
Abstract:
PURPOSE: A wireless power transmission device and method for reducing radiated power of a magnetic resonator are provided to transmit energy by selecting a frequency having relatively low radiated power. CONSTITUTION: A signal generator(102) generates a frequency signal used for wireless energy transmission from general commercial AC powder. A power amplifying unit(104) amplifies the frequency signal. A signal detection unit(106) transfers the amplified signal to a magnetic resonator for wireless energy transmission and detects a radiated signal caused by the magnetic resonator. A standing-wave ratio calculation unit(108) calculates a standing-wave ratio from the detected signal. A control unit selects the frequency having the lowest standing-wave ratio using the standing-wave ratios calculated by the standing-wave ratio calculation unit.
Abstract:
PURPOSE: An antenna is provided to obtain high isolation by attenuating a transmission signal which does not pass through an object. CONSTITUTION: A first antenna(2) and a second antenna(3) are vertically arranged with each other. A third antenna(4) and a fifth antenna(6) are symmetrical based on the plane formed by the first and second antennas. The third antenna and a fifth antenna are vertical to the first antenna. The inner cores of a feeding connector of the third and fifth antennas are arranged in the opposite direction. A fourth antenna(5) and a sixth antenna(7) are symmetrical based on the plane formed by the first and second antennas. The fourth antenna and the sixth antenna are horizontal to the first antenna.
Abstract:
A resource allocation method for an OFDM(Orthogonal Frequency Division Multiplexing Access) system is provided to maximize diversity without decreasing degree of freedom of sub-band selection. According to a resource allocation method for an OFDM(Orthogonal Frequency Division Multiplexing Access) system, a plurality of sub-bands is generated by partitioning an occupied frequency band of a fixed number of OFDM symbols, and the number of diversity sub-channels including more than two time/frequency resources belonging to the different sub-band and the number of sub-band selection sub-channels constituted with time/frequency resource not belonging to the diversity sub-channel are determined. A diversity sub-channel and a sub-band selection sub-channel are generated according to the determined number, and a physical channel constituted with the generated sub-channel is allocated to a user in a cell.
Abstract:
An antenna device for diagnosis of target part is provided to reduce hardware complexity, to enhance isolation rate between a transmitting module and a receiving module and to diagnose cancer accurately. An antenna device for diagnosis of target part contains a tank including medium having relative dielectric constant opposed to organization of the target part and having an opening, an antenna frame(112) formed inside the tank, an array antenna including a plurality of antennae, mounted in the antenna frame and extended to a vertical direction in order to surround the target part inserted through the opening, an azimuth motor control module generating a control signal for rotating the antenna frame as a rotation angle determined to azimuthal direction and an elevation motor(116) rotating the antenna frame according to control of the azimuth motor control module. A first antenna of the plurality of antennae includes a transmission module radiating a micro wave signal.
Abstract:
A method and an apparatus for allocating a hybrid burst in an OFDMA(Orthogonal Frequency Division Multiple Access) system is provided to reduce a burst allocation information bit and an overhead size by allocating a burst using a burst length. A method for allocating a hybrid burst in an OFDMA system includes the steps of: sequentially allocating the bursts, which are mapped along a frequency axis for a downlink data transmission, to each terminal(S630); dividing the data burst region of the sub-frame into at least one segment in the time region and sequentially allocating the bursts, which are mapped in the segment along the time axis, to each terminal(S650); sequentially allocating the bursts, which are mapped along a time axis for an uplink data transmission, to each terminal(S670); and sequentially allocating the bursts which are mapped along a whole time axis of a data burst region of the sub-frame to each terminal, to each terminal(S680).