Abstract: The present disclosure provides apparatuses or methods for detecting a PIM generation point, which can enhance the accuracy of the PIM generation point detection up to a level of 10 centimeters, and thus enable rapid replacement or maintenance of a disfunctional element causing the PIM by installing and controlling a time delay module in an output end of a reference signal (or, a PIM signal) for detection of the PIM generation point.

Abstract: Provided is a PIM detection apparatus including: a tone signal input unit configured to apply a tone signal having a first frequency characteristic to a test target apparatus; a sequence signal input unit configured to apply a sequence signal having a second frequency characteristic to the test target apparatus; a PIM detector configured to receive a Passive Intermodulation (PIM) signal from the test target apparatus, and to detect a delay time and a size of the PIM signal based on the sequence signal; and a PIM position determiner configured to determine a PIM occurrence position by using the delay time and the size of the PIM signal.

Abstract: The present disclosure provides apparatuses or methods for detecting a PIM generation point, which can enhance the accuracy of the PIM generation point detection up to a level of 10 centimeters, and thus enable rapid replacement or maintenance of a disfunctional element causing the PIM by installing and controlling a time delay module in an output end of a reference signal (or, a PIM signal) for detection of the PIM generation point.

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.

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 network management apparatus for priority channel assignment to acquire available channels in a frequency sharing band, including: a signal intensity measurer measuring a received signal intensity for an input signal; and a controller verifying usable candidate channels in the same channel and an adjacent channel of a TV band device (TVBD) for each predetermined frequency based on the measured received signal intensity, verifying available channels of the TVBD based on the verified usable candidate channels in the same channel and the adjacent channel, calculating the decreased number of available channels of the TVBD predicted for each channel after channel reassignment, and assigning channels to be reassigned based on the calculated decreased number of available channels of the TVBD.

Abstract: Disclosed is a method for calculating a radio coverage in a wireless device for calculating a protective distance so as not to allow a secondary user sharing a frequency with a primary user to have an effect of radio interference on the primary user, the method including: calculating a transmission power of a wireless signal transmitted through the frequency by the secondary user; determining a region affected by the wireless signal based on the transmission power of the secondary user; calculating an average ground clearance of the determined region; calculating a height of an installation place of an antenna of the secondary user from the average ground clearance; and calculating the height of the antenna from the average ground clearance by adding a length of the antenna of the secondary user to the calculated height and calculating the radio coverage based on the height from the average ground clearance.

Abstract: Disclosed is an apparatus for converting a frequency. The apparatus includes: an oscillator configured to generate a first oscillation signal having a first oscillation frequency which is obtained by subtracting an input frequency from a carrier frequency of any one carrier signal among a first to a n-th carrier signals (n is a natural number), and generate a second oscillation signal having a second oscillation frequency which is obtained by adding the input frequency to a carrier frequency of any one carrier signal among a (n+1)-th to a 2n-th carrier signals; and a mixer configured to mix and output the first oscillation signal or the second oscillation signal with an input signal having the input frequency.

Abstract: Disclosed is a resource allocating method of a base station, which includes receiving information on an existence signal of another base station or a coexistence frame in a transmission frame of another base station from a terminal, making time synchronization with another base station and frame synchronization with the coexistence frame of another base station coincide with each other, and allocating a signal transmission frame so as not to overlap the signal transmission frame in the transmission frame of another base station.

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 an apparatus and a method for coexistence of heterogeneous services of a user terminal, which can enhance performance of a wireless communication network by simultaneously providing heterogeneous services such as an LTE-U service and a WiFi service to coexist without signal interference in unlicensed bands through effectively performing selection of a frequency band and selection of a transmission spectrum type in respective service modules of the user terminal.

Abstract: Disclosed is an apparatus for converting a frequency. The apparatus includes: an oscillator configured to generate a first oscillation signal having a first oscillation frequency which is obtained by subtracting an input frequency from a carrier frequency of any one carrier signal among a first to a n-th carrier signals (n is a natural number), and generate a second oscillation signal having a second oscillation frequency which is obtained by adding the input frequency to a carrier frequency of any one carrier signal among a (n+1)-th to a 2n-th carrier signals; and a mixer configured to mix and output the first oscillation signal or the second oscillation signal with an input signal having the input frequency.

Abstract: Disclosed is a communication method for coexisting with a non-licensed band communication system of a non-licensed band in a licensed band communication system. The method includes: transmitting a signal by a transmitter in order to operate in a non-licensed band, when the signal is a transmission target signal having frames and a wireless local area network (WLAN) preamble signal is inserted to the front of each frame of the transmission target signal; and extracting the WLAN preamble signal from the signal of the transmitter by a receiver to synchronize with the transmitter.

Abstract: Provided is a frequency sensing method and apparatus in an orthogonal frequency division multiplexing (OFDM) system. Provided is a method of sensing a frequency of a received signal that is received from an outside in order to perform one of a plurality of radio communications. An OFDM apparatus may need to inspect a required frequency band before or after performing one of the plurality of radio communications, and to determine whether the frequency band is being used by another radio communication.

Abstract: Disclosed is a network management apparatus for priority channel assignment to acquire available channels in a frequency sharing band, including: a signal intensity measurer measuring a received signal intensity for an input signal; and a controller verifying usable candidate channels in the same channel and an adjacent channel of a TV band device (TVBD) for each predetermined frequency based on the measured received signal intensity, verifying available channels of the TVBD based on the verified usable candidate channels in the same channel and the adjacent channel, calculating the decreased number of available channels of the TVBD predicted for each channel after channel reassignment, and assigning channels to be reassigned based on the calculated decreased number of available channels of the TVBD.

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 calculating a radio coverage in a wireless device for calculating a protective distance so as not to allow a secondary user sharing a frequency with a primary user to have an effect of radio interference on the primary user, the method including: calculating a transmission power of a wireless signal transmitted through the frequency by the secondary user; determining a region affected by the wireless signal based on the transmission power of the secondary user; calculating an average ground clearance of the determined region; calculating a height of an installation place of an antenna of the secondary user from the average ground clearance; and calculating the height of the antenna from the average ground clearance by adding a length of the antenna of the secondary user to the calculated height and calculating the radio coverage based on the height from the average ground clearance.

Abstract: Disclosed is a method of allocating radio resources, including: acquiring available channel information of a cognitive radio small cell; analyzing a channel characteristic based on the available channel information and dividing a required transmission rate of the cognitive radio small cell into required transmission rates for each available channel; and performing a power control for each available channel based on the divided required transmission rates for each available channel. The method of allocating radio resources may be performed under an interference environment in which a plurality of cognitive radio small cells is present and the plurality of cognitive radio small cells shares an available channel.

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.

Abstract: Disclosed is a method of allocating radio resources, including: acquiring available channel information of a cognitive radio small cell; analyzing a channel characteristic based on the available channel information and dividing a required transmission rate of the cognitive radio small cell into required transmission rates for each available channel; and performing a power control for each available channel based on the divided required transmission rates for each available channel. The method of allocating radio resources may be performed under an interference environment in which a plurality of cognitive radio small cells is present and the plurality of cognitive radio small cells shares an available channel.