Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Seung Jae Bahng

Youn Ok Park

Youn-Ok Park

Heesoo Lee

Jung Sook Bae

Dae Ho Kim

Young Jo Bang

Chang Wahn Yu

An Seok Lee

Jun Woo Kim

Young Ha Lee

Jun Sik Kim

Hoon Do Heo

Jun-Woo Kim

Kyung Yeol Sohn

Go San Noh

Soon Gi Park

Jung Pil Choi

Hyeong Sook Park

Jae Kwon Kim

Hyun Myung Wu

Hoon Ki Lee

Dong Seung Kwon

Jee Hwan Ahn

Ji Soo Park

Yong Su Lee

Eon Young Hong

Young Jin Moon

Il Min Kim

Dong Weon Yoon

Kwang Min Hyun

Disclosed are a method and an apparatus for codebook design in a communication system. A method of a base station may comprise: transmitting a pilot signal to a terminal by using a reconfigurable intelligent surface (RIS); receiving, from the terminal, channel information measured based on the pilot signal; estimating characteristics of elements of the RIS based on the channel information; generating a codebook based on the estimated characteristics of the elements; and transmitting the codebook to a controller of the RIS.

Method and apparatus for codebook design in communication system

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.

Beam search method and apparatus in smart repeater system

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.

Method and apparatus for switching aerial base stations in wireless communication system

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.

Method and apparatus for initial access in communication system

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.

Method and apparatus for controlling beam in wireless communication system

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.

Method for data retransmission in wireless communication system and apparatus for the same

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.

Transmitter and receiver of signals through polarization antenna and methods for controlling the same

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.

Base station and signal transmitting control method of the same, and wireless communication system

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.

Wireless communication apparatus and method for selecting a group of coordinated communication nodes based on signal intensities and delay times of source signals

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.

Communication apparatus and communication system including the same, and dual polarization signal transmitting and receiving method of communication system

Disclosed is a method and apparatus for composing a received symbol signal modulated with a bit reflected Gray code into bit information. According to an embodiment of the present invention, a positive integer of the received symbol signal having bits is assigned according to the Gray mapping rule, and a sign is determined. A value that is indicative of an arrangement of the bits constituting the received symbol signal is calculated. A boundary value in at least one bit group consisting of the bits constituting the received symbol signal is acquired, and a difference from an absolute value of the received symbol signal is calculated. The received symbol signal is converted into information per bit using a value of the received symbol signal based on the positive integer and the determined sign, the value that is indicative of the bit arrangement, and the difference from the absolute value. Therefore, it is possible to reduce complexity in bitwise decomposition for an iterative decoder inevitably used in a receiver.

Method and apparatus for decomposing received symbol signal modulated with bit reflected gray code in bit information

Disclosed are a row-vector norm comparison method and a row-vector norm comparison apparatus for an inverse matrix. A row-vector norm comparison apparatus includes: an input matrix processing module that receives and combines constituent elements of a matrix; a cofactor operation module that multiplexes the combination result of the constituent elements to calculate factors constituting an adjoint matrix; a square calculation module that squares the calculated factors; a summation module that selects a predetermined number of factors among the squared factors and sums the selected factors to calculate the norms of row vectors in an inverse matrix; and a norm comparison module that outputs a comparison result of the calculated norms of the row vectors. A row-vector norm comparison method includes: combining constituent elements of a matrix to generates a plurality of combination results of the constituent elements; multiplexing the combination results to calculate factors constituting an adjoint matrix of the matrix; squaring the calculated factors and selectively summing the squared factors; and calculating the norms of row vectors in an inverse matrix and comparing the calculated norms of the row vectors. With this configuration, row-vector norm comparison for an inverse matrix can be performed with a design structure. Therefore, it is not necessary to use an existing complex operation method. In addition, low power consumption of the multiple antenna system can be achieved, and efficiency of the design structure can be improved.

Row-vector norm comparison method and row-vector norm comparison apparatus for inverse matrix

The present invention relates to a transmission symbol detection method in a multiple antenna system. In the present invention, when a channel matrix is estimated through channel estimation, a receiving side calculates a Q matrix and an R matrix through QR decomposition that is more simplified than a typical QR decomposition from an augmented channel matrix that includes the estimated channel matrix. In addition, the receiving side detects symbols having the minimum Euclidean metric by using the two matrixes, as transmission symbols.

Method for detecting transmission symbols in multiple antenna system

The present invention relates to a method of calculating a soft value and a method of detecting a transmission signal. The present invention estimates a channel on the basis of a received signal and rearranges a plurality of data streams. Further, a plurality of substitute vectors are selected from the rearranged data streams and a metric corresponding to each of the substitute vector is calculated. Further, a threshold value is calculated from a metric calculated for each of the substitute vectors and a soft value of each bit of a transmission signal is calculated from the metric and threshold value corresponding to each of the substitute vectors.

Method of calculating soft value and method of detecting transmission signal

The present invention relates to a method of detecting a candidate vector and a method of detecting a transmission symbol using the same. According to an embodiment of the present invention, in a multiple input multiple output (MIMO) system using spatial multiplexing (SM), a receiver selects candidate vectors corresponding to a layer located at a last row among a plurality of rearranged layers, and sequentially ranks constellation dots of a next layer for each of the selected candidate vectors. Then, a plurality of arbitrary constellation dots are selected from the ranked constellation dots, accumulated costs of the arbitrary constellation dots are calculated, and a candidate vector is selected in correspondence with a constellation dot having a minimal accumulated cost. Then, a new arbitrary constellation dot is selected in place of the constellation dot selected as the candidate vector, an accumulated cost of the selected arbitrary constellation dot is compared with accumulated costs of the other arbitrary constellation dots, and another candidate vector is selected.

Growing community of inventors

Daejeon, South Korea

Seung Jae Bahng