Abstract: An operation method of a first device in a communication system may comprise: receiving, at a second device, a primary synchronization signal block (SSB) including first SSBs for the first device; feeding back to the second device an index of a first SSB with a highest received signal strength among the first SSBs of the first SSB set; receiving, at the second device, a second SSB set including the first SSBs for the first device and second SSBs for a third device; transmitting to the third device the second SSBs for the third device in the second SSB set; and forwarding an index of a second SSB with a highest received signal strength among the second SSBs to the second device, the index being received from the third device.

Abstract: A method for controlling base stations in a wireless communication system may include: performing a monitoring operation on a first base station forming a first cell in a predetermined communication area; determining whether the first base station needs to be replaced; when the first base station needs to be replaced, controlling a second base station to move in a direction of the first base station and form a second cell; when coverages of the first and second cells overlap fully or partially, decreasing a transmit power of the first base station and increasing a transmit power of the second base station; and in response to identifying that all of one or more communication nodes connected to the first cell are handed over to the second base station, determining that the first base station is successfully replaced with the second base station.

Abstract: An operation method performed by an access point in a communication system may comprise: transmitting, to a first station, a first frame by using a third communication scheme, the first frame including information on an address of the first station, a first transmission time length, a first reception order, and a first communication scheme to be used for transmitting data to the first station, and information on a second transmission time length, a second reception order, and a second communication scheme to be used for transmitting second data to one or more second stations; receiving, from the first station, a first response frame for the first frame from the first station at a first reception time; and receiving, from the second station, a second response frame for the first frame at a second reception time.

Abstract: An operation method of a terminal for initial access in a communication system may comprise: receiving a plurality of SSBs having different indexes through a plurality of antennas included in a base station; calculating a channel capacity using the plurality of SSBs; feeding back, to the base station, index(es) of one or more SSBs for having a maximum channel capacity among the plurality of SSBs; and performing communication with the base station through a combination of two or more antennas that have transmitted the one or more SSBs for having the maximum channel capacity among the plurality of antennas.

Abstract: A beam alignment method performed by a first communication node in a communication system may comprise: identifying a position of a first antenna of the first communication node; configuring a first coordinate system based on a physical position and direction of the first antenna, based on information on the position of the first antenna; identifying a position of a second antenna of a second communication node of the communication system; converting information on the position of the second antenna into coordinate information based on the first coordinate system; calculating direction change values of the first antenna based on the information on the position of the second antenna, which is converted based on the first coordinate system; changing a direction of the first antenna based on the direction change values of the first antenna; and updating a beam alignment state between the first and second antennas.

Abstract: An operation method of a transmitting apparatus in a wireless communication system includes transmitting, to a receiving apparatus, reverse mapping flag information indicating a direction of mapping data symbols to one or more subcarriers included in a resource block allocated to the receiving apparatus; mapping the data symbols to the one or more subcarriers of the resource block based on the reverse mapping flag information; and transmitting the resource block to the receiving apparatus. According to the embodiments of the present disclosure, the amount of subcarrier phase shift noises due to an SFO occurring in proportion to synchronization impairment and subcarrier index can be reduced in a multi-carrier communication system, thereby increasing data retransmission efficiency.

Abstract: An operation method of a transmitting apparatus in a wireless communication system includes transmitting, to a receiving apparatus, reverse mapping flag information indicating a direction of mapping data symbols to one or more subcarriers included in a resource block allocated to the receiving apparatus; mapping the data symbols to the one or more subcarriers of the resource block based on the reverse mapping flag information; and transmitting the resource block to the receiving apparatus. According to the embodiments of the present disclosure, the amount of subcarrier phase shift noises due to an SFO occurring in proportion to synchronization impairment and subcarrier index can be reduced in a multi-carrier communication system, thereby increasing data retransmission efficiency.

Abstract: Disclosed is a data transmitter, including: a demultiplexer configured to demultiplex a data subcarrier, and a training sequence or a pilot subcarrier included in a signal which needs to be frequency-shifted among a plurality of signals; a frequency shift unit configured to frequency-shift the demultiplexed data subcarrier based on a predetermined frequency; a superposition unit configured to generate a polarization signal by superimposing the demultiplexed training sequence or pilot subcarrier, and the frequency-shifted data subcarrier; and a polarization antenna configured to transmit a signal which need not be frequency-shifted and the generated polarization signal among the plurality of signals.

Abstract: Disclosed is a base station transmitting multiple beams to multiple beam areas, including: a determination unit determining at least any one of whether a downlink control signal is transmitted through the multiple beams transmitted to the multiple beam areas and a transmission section; a generation unit generating signal transmitting control information including at least any one of whether the downlink control signal is transmitted, the transmission section of the downlink control signal, and derivation information to derive a change of an access beam for a terminal that accesses the multiple beams; a communication unit downlink-transmitting the signal transmitting control information to the multiple beam areas or the multiple beams; and a control unit controlling transmission of the downlink control signal based on the signal transmitting control information.

Abstract: Disclosed is a base station transmitting multiple beams to multiple beam areas, including: a determination unit determining at least any one of whether a downlink control signal is transmitted through the multiple beams transmitted to the multiple beam areas and a transmission section; a generation unit generating signal transmitting control information including at least any one of whether the downlink control signal is transmitted, the transmission section of the downlink control signal, and derivation information to derive a change of an access beam for a terminal that accesses the multiple beams; a communication unit downlink-transmitting the signal transmitting control information to the multiple beam areas or the multiple beams; and a control unit controlling transmission of the downlink control signal based on the signal transmitting control information.

Abstract: Provided are multiple polarized input multiple output system and method for wireless communication which are capable of simultaneously transmitting respective data streams to a plurality of users by transmitting from multiple polarized input to multiple output in proportion to the number of polarized antennas or the number of polarizations used in a transmitter.

Abstract: Disclosed are a method and an apparatus that efficiently generate a DFT-ed preamble sequence used in uplink PRACH transmission of a wireless communication system. The method for generating a DFT-ed preamble sequence in a wireless communication system includes: calculating a first index value corresponding to the length of a DFT-ed preamble sequence by using control information; extracting a value on a unit circle corresponding to the first index value or a value on the unit circle corresponding to a second index value acquired by transforming the first index value according to a preamble format; reflecting a sign on the unit circle including the corresponding index value to the extracted value on the unit circle; and multiplying a value to which the sign is reflected by an initial sequence value according to a root index.

Abstract: Disclosed is a base station that performs coordinated communication with a plurality of remote radio heads (RRHs), including: a communication unit receiving source signals from the plurality of remote radio heads; a measurement unit measuring signal intensities and delay times of the respective source signals; a selection unit selecting remote radio heads that will perform the coordinated communication among the plurality of remote radio heads based on the signal intensities and the delay times; and a demodulation unit demodulating source signals received from the selected remote radio heads.

Abstract: Disclosed is a communication system including a first communication apparatus and a second communication apparatus that communicate with each other through a dual polarization antenna, the system including: a first communication apparatus which calculates a co-polar ratio defined by a ratio of a first channel gain for a first polarization and a second channel gain for a second polarization; and a second communication apparatus which calculates a first rotation angle for the first polarization and a second rotation angle for the second polarization, respectively, by using the co-polar ratio transferred from the first communication apparatus, and transmits to the first communication apparatus a first rotational polarization generated by rotating the first polarization at the first rotation angle and a second rotational polarization generated by rotating the second polarization at the second rotation angle.

Abstract: Disclosed are a method and an apparatus for data transmission that apply a transmission diversity method which does not decrease transmission rate even when the number of transmission antennas is 3 or more for frequency division multiplexing scheme downlink cooperation communication to allow a terminal to have an excellent diversity characteristic.

Abstract: Disclosed is a base station that performs coordinated communication with a plurality of remote radio heads (RRHs), including: a communication unit receiving source signals from the plurality of remote radio heads; a measurement unit measuring signal intensities and delay times of the respective source signals; a selection unit selecting remote radio heads that will perform the coordinated communication among the plurality of remote radio heads based on the signal intensities and the delay times; and a demodulation unit demodulating source signals received from the selected remote radio heads.

Abstract: Disclosed is a data transmitter, including: a demultiplexer configured to demultiplex a data subcarrier, and a training sequence or a pilot subcarrier included in a signal which needs to be frequency-shifted among a plurality of signals; a frequency shift unit configured to frequency-shift the demultiplexed data subcarrier based on a predetermined frequency; a superposition unit configured to generate a polarization signal by superimposing the demultiplexed training sequence or pilot subcarrier, and the frequency-shifted data subcarrier; and a polarization antenna configured to transmit a signal which need not be frequency-shifted and the generated polarization signal among the plurality of signals.

Abstract: Disclosed is a communication system including a first communication apparatus and a second communication apparatus that communicate with each other through a dual polarization antenna, the system including: a first communication apparatus which calculates a co-polar ratio defined by a ratio of a first channel gain for a first polarization and a second channel gain for a second polarization; and a second communication apparatus which calculates a first rotation angle for the first polarization and a second rotation angle for the second polarization, respectively, by using the co-polar ratio transferred from the first communication apparatus, and transmits to the first communication apparatus a first rotational polarization generated by rotating the first polarization at the first rotation angle and a second rotational polarization generated by rotating the second polarization at the second rotation angle.

Abstract: There are provided a method of generating a ranging signal of a wireless terminal and a device for generating a ranging signal of a wireless communication system that can generate the ranging signal using one IFFT engine independently from a mode of the ranging signal transmitted in uplink in a wireless communication system in which a frequency interval of subcarriers used to generate an initial ranging signal and a frequency interval of subcarriers using periodic ranging are different. In this way, it is possible to decrease complexity of hardware and design of the wireless terminal, and decrease power consumption of the wireless terminal through hardware simplification.

Abstract: Disclosed is an apparatus for transmitting multiple streams, including: a polarized wave control unit generating non-orthogonal polarization information for three or more input streams; a polarized wave generating unit polarizing three or more input streams in a baseband based on the non-orthogonal polarization information to generate vertical and horizontal polarization components; and a polarized wave transmitting unit transmitting the plurality of vertical and horizontal polarization components through dual polarization antennas.