Electronics and Telecommunications Research Institute

Junhyeong Kim

Il Gyu Kim

Bing Hui

Hee Sang Chung

Sung Woo Choi

Gosan Noh

Hoon Ki Lee

Yeong Jin Kim

Sung Yeol Choi

Seung Chan Bang

Hyun Kyu Chung

Jun Hwan Lee

Provided are a method and a device for triggering a beam failure recovery (BFR) procedure of a multibeam system by means of the steps of: detecting a beam failure by monitoring a wireless link connected with a base station; identifying a candidate transmission beam of the base station; and transmitting a BFR request to the base station when the candidate transmission beam of the base station is identified.

Method and device for triggering beam failure recovery procedure of multibeam system

A method for transmitting and receiving a message for a random access (RA) between user equipment (UE) and a base station in a multi beam system includes: transmitting a synchronization signal (SS) block including a synchronization signal by performing beam sweeping for a multi beam; receiving a message 1 of an RA procedure from the UE; determining an optimal transmission beam to be used to transmit a message 2 of the RA procedure based on information about an association mapping between the SS block and a physical random access channel (PRACH) which is used to transmit the message 1; and transmitting the message 2 by using the optimal transmission beam.

Method for transmitting and receiving message for random access in multi beam system

A method and an apparatus for random access in a mobile communication system are provided. A terminal receives a synchronization signal block, obtains beam index information from the received synchronization signal block, and transmits a preamble message occupying a plurality of preamble resources including a preamble resource corresponding to the beam index information to a base station. A random access resource includes a plurality of preamble resources, and the synchronization signal block is specified for one beam and corresponds to one preamble resource of the random access resource.

Method and apparatus for random access in mobile communication system

A method and an apparatus for transmitting a message used to access a base station (BS) in a random access (RA) procedure by user equipment (UE) are provided. The method includes: determining a first RA preamble resource corresponding to an SSB index which corresponds to a transmission beam among a plurality of transmission beams of BS; and transmitting a message 1 of the RA procedure by using a first RA preamble format which includes the first RA preamble resource and at least one second RA preamble resource which neighbors the first RA preamble resource.

Method and apparatus for transmitting RA preamble in NR system

A high speed moving terminal including first and second antennas each communicating with first and second radio units (RUs) of a base station distributedly installed in a mobile wireless backhaul network communicates with the first and second RUs, respectively, with different uplink-downlink configuration of the first RU and the second RU, and transmits control information of the corresponding downlink signal in an uplink subframe that comes first in the time domain after processing latency of a downlink signal received from the first RU among uplink frames with the uplink-downlink configurations of the first RU and the second RU if the downlink signal is received from the first RU through the first antenna.

High speed moving terminal and method for transmitting control information thereof, and method for receiving control information of base station in mobile wireless backhaul network

A method and user equipment for transmitting a message of a random access procedure in a multi-beam system includes: transmitting and retransmitting a message 1 of the RA procedure through a first beam of a plurality of transmission beams of the UE based on power ramping; and retransmitting, if one or more Msg. 2 (RAR) is not successfully received corresponding to the message 1 transmission/retransmission, the message 1 through a second beam of the plurality of transmission beams after switching the first beam to the second beam at a second power level which is the same as or higher than a first power level of the first beam.

User equipment and method for transmitting message in multi-beam system

An apparatus and method for beam-forming communication in a mobile wireless backhaul network. The apparatus included in a base station includes: an antenna unit radiating a beam according to predetermined beam characteristics and transmitting a signal of the base station to a mobile terminal in a high speed moving body; a position searching unit detecting a distance, a speed, and a direction of movement between the base station and the mobile terminal; a beam setting unit grouping one or more beams according to the detected distance between the base station and the mobile terminal and setting the number of beam search groups in which a beam search is to be performed and a beam search period according to the detected speed and direction of movement; and a beam searching unit searching for the beam of the mobile terminal based on beam setting values set by the beam setting unit.

Apparatus and method for beam-forming communication in mobile wireless backhaul network

A radio unit (RU) in a directional communication network establishes a connection with a first antenna among two antennas of a first TE in a first moving object that first enters a serving duration of the RU according to a network access request from the first antenna, and when receiving the network access request from a second antenna among two antennas of a second TE in a second moving object that next enters the serving duration, the RU processes the network access request from the second antenna based on network access priority of the second antenna and network access priority of the first antenna to which the connection is established.

Method and apparatus for controlling network access in directional communication networks

A method for transmitting and receiving a signal using steps of transmitting an uplink signal to a base station in a duration of an uplink pilot time slot (UpPTS) of a special subframe, and waiting for a guard time (GT) before receiving a downlink signal from the base station after the transmission of the uplink signal, and a terminal transmitting and receiving a signal by using the method.

Method and apparatus for transmitting and receiving signal in high speed train communication network

A transmitting apparatus for modulating data based on a predetermined 2-QAM constellation and a receiving apparatus and method for demodulating a signal based on the predetermined 2-QAM constellation, wherein the last q-2 bits corresponding to a quadrant of the predetermined 2-QAM constellation are same with a gray code of a 2-QAM constellation, the last q-2 bits corresponding to the remaining quadrants of the predetermined 2-QAM constellation are determined by performing symmetric transformation for the last q-2 bits of the quadrant of the predetermined 2-QAM around the x-axis or the y-axis.

Apparatus and method for transmitting and receiving signal based on QAM constellation

Disclosed herein is an adaptive communication method of a base station in a moving wireless backhaul network, including: acquiring frame transmitting/receiving timings of a terminal; periodically searching for a terminal synchronous signal transmitted from the terminal; if the terminal synchronous signal is detected, estimating the frame transmitting/receiving timings of the base station to/from the terminal based on the terminal synchronous signal and the frame transmitting/receiving timings of the terminal; and transmitting the base station synchronous signal to the terminal based on the frame transmitting/receiving timings of the base station.

Method of receiving downlink signal of high speed moving terminal, adaptive communication method and adaptive communication apparatus in mobile wireless backhaul network

Disclosed is a method and apparatus for communication in a millimeter band communication system. In a case in which a first terminal obtains a list including members of a cooperative group in which terminals receive a service with the same beam as a first terminal's beam, the first terminal informs a second terminal, corresponding to a member of the list, of communication link failure when the failure occurs, and requests a cooperative service. After that, the first terminal receives information on the service from a base station through the second terminal.

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Daejeon, South Korea

Junhyeong Kim