Electronics and Telecommunications Research Institute

Bing Hui

Il Gyu Kim

Hee Sang Chung

Junhyeong Kim

Sung Woo Choi

Gosan Noh

Hoon Ki Lee

Yeong Jin Kim

Jun Hwan Lee

Go San Noh

Jun Hyeong Kim

Hyun Kyu Chung

Sung Yeol Choi

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

An operation method of a terminal in a communication system includes receiving a message from a base station, the message including physical random access channel (PRACH) configuration information indicating a PRACH slot; determining a start symbol to which a PRACH is mapped among symbols constituting the PRACH slot based on a type of the PRACH slot; mapping the PRACH from the start symbol in the PRACH slot; and transmitting the PRACH mapped to the PRACH slot to the base station.

Method for transmitting and receiving physical random access channel in communication 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 of performing, by a device, a random access procedure in a radio communication system includes: receiving from a base station RACH configuration information; and transmitting a first message based on the received RACH configuration information. Herein, a plurality of SSBs may be in association with a plurality of preambles, and the first message may be transmitted in a time domain through a plurality of RACH resources.

SSB to RACH resource associations and related RACH configuration contents in multi-beam 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 method and a terrestrial base station for receiving an uplink signal. The terrestrial base station is configured to: receive a preamble corresponding to an orthogonal pseudo-noise (PN) sequence of a plurality of the orthogonal PN sequences from an onboard base station in a train; recognize identification (ID) of the onboard base station from the preamble, and allocate a temporary network ID and an uplink grant (UL grant) to the onboard base station; and receive the uplink signal transmitted based on the temporary network ID and the UL grant.

Method and apparatus for receiving uplink signal in train communication 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.

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Daejeon, South Korea

Bing Hui