Abstract:
A wireless communication method may include performing, by a first system, channel monitoring of a first band, detecting a second system that uses the first band, determining whether the first system is to be used in preference to the second system, and allocating a radio resource of the first band to the first system based on whether the first system is to be used in preference to the second system.
Abstract:
Disclosed are an available channel information sharing system and an available channel information sharing method, and an available channel information sharing system and an available channel information sharing method based on positional information and area information.The available channel information sharing system sharing available channel information for each unit region includes: a server; a white band device placed in the unit region; and a white band sensing device creating positional information and transmitting the created positional information to the server, receiving unit region information corresponding to the positional information from the server, and transmitting first available channel information based on channel information of a sensed broadcasting signal to the white band device.
Abstract:
Disclosed is a method for generating and transmitting a reference signal in a clustered DFT-spread OFDM transmission scheme. A method for generating and transmitting a DM-RS in a clustered DFT-spread-OFDM scheme comprises: a step of generating DM-RS sequences corresponding to the number of clusters allocated for an uplink transmission; and a step of mapping the generated DM-RS sequences to the relevant DM-RS symbol positions for each cluster. Accordingly, the method for generating and transmitting a reference signal according to the present invention, in which DM-RS sequences are allocated and transmitted on a cluster basis, uses a complete DM-RS sequence for each cluster, and therefore inter-cell interference can be weakened, and problems which might occur when applied to a multi-user MIMO (MU-MIMO) scheme can be solved.
Abstract:
Provided is an apparatus and method for controlling a transmission output of a radio device using a television (TV) band based on a frequency band, the apparatus including a frequency band selecting unit to select frequency bands to be compared, a radio wave attenuation calculation unit to calculate a radio wave attenuation for each of the selected frequency bands, and a transmission output control unit to automatically control the transmission output of the radio device using a TV band based on a difference value among the calculated attenuation values. According to an example embodiment, it is possible to extend a service area while sufficiently protecting a service being provided in the TV band, thereby realizing an efficient use of frequency resources.
Abstract:
Disclosed is a method for improving the efficiency of sharing a frequency between a plurality of adjacent systems using an idle band. A method for allocating an operating channel priority between frequency sharing systems according to the present invention includes: a coarse channel priority allocating operation of collecting information about a target white space object (WSO) for priority allocation of an operating channel and information about the operating channel, and classifying the operating channel based on a predetermined criterion; and a fine channel priority allocating operation of removing the operating channel by checking an interference level of the classified operating channel.
Abstract:
A wideband transmitting and receiving apparatus including a local oscillator (LO) synthesizer providing a constant output to a wide band is provided. The LO synthesizer may generate LO signals of different amplitudes according to channels. The LO synthesizer may store the amplitudes of the LO signals different according to the channels and compensate the amplitudes of the LO signals using the stored amplitudes. Accordingly, the LO synthesizer may output the LO signals of uniform amplitudes irrespective of the channels.
Abstract:
A method for calculating an altitude of a target through an apparatus for calculating an altitude of the target, which comprises a plurality of MIMO radar virtual antennas, may comprise: receiving electromagnetic waves reflected from the target through a pair of virtual antennas classified into an upper antenna and a lower antenna and alternately arranged in two columns linearly; obtaining range information and phase information of the target from the pair of virtual antennas by analyzing the electromagnetic waves; and calculating altitude information of the target from position information of the pair of virtual antennas, and the range information and the phase information.
Abstract:
A method of transmitting and receiving an orthogonal frequency division multiplexing (OFDM) signal for radio detection and ranging (radar) applications, and apparatuses performing the method are disclosed. The method includes receiving an OFDM signal in which a cyclic prefix (CP) is not included and converting the received OFDM signal to a received discrete time-domain signal through an analog-to-digital converter (ADC), selecting sub-carrier symbols to be input to a fast Fourier transform (FFT) from among all sub-carrier symbols included in the received discrete time-domain signal by performing windowing on the received discrete time-domain signal by a window that is based on an estimated value of a maximum delay that occurs potentially in a channel, converting the received discrete time-domain signal to a received frequency-domain signal by inputting the selected sub-carrier symbols to the FFT, and performing channel estimation based on the received frequency-domain signal.
Abstract:
When a feature of the present invention is summarized, disclosed is a frame structure of transmitted and received data in a wireless communication system, including: a plurality of uplink subframes (UL) or downlink subframes (DL) for transmitting and receiving data; and a coexistence synchronization signal preamble for frequency coexistence among asynchronous cells.
Abstract:
Disclosed are a wireless communication apparatus for reducing interference by a neighboring cell, and a method of reducing interference thereof. The method of reducing interference by a wireless communication apparatus includes: determining a neighboring small cell from one or more surrounding small cells adjacent to a small cell; allocating a communication resource to one or more users according to a channel state of the one or more users subscribing to the small cell; and transmitting data to the one or more users, to which the communication resource is allocated, by adopting one or more interference reducing methods for reducing interference by the neighboring small cell.