Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A base station in a mobile communication system determines the number of slots that are to be used to transmit a synchronization signal in a period of the synchronization signal depending on the number of neighbor cells, allocates a synchronization signal region in which the synchronization signal is to be transmitted to a first slot of the determined number of slots depending on a cell identifier of a serving cell, and allocates a reserved region in which no signal is transmitted to slots other than the first slot among the determined number of slots so as to correspond to a position of the synchronization signal region.

Abstract: 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.

Abstract: 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.

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

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and apparatus for scheduling a beam in a mobile communication system are provided. A terminal receives signals through a plurality of switching beam directions, and receives a plurality of beams that are transmitted while performing beam switching in a transmission time interval (TTI) unit by a base station. The terminal selects a signal having largest intensity among received signals, and transmits an uplink scheduling request signal in a beam direction corresponding to the selected signal.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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

Abstract: Disclosed is a random access method for a machine type communication (MTC) terminal. The random access method performed by a terminal includes performing a cell search, determining a radio environment based on time taken to perform the cell search, and performing different random access procedures depending on the determined radio environment. Accordingly, coverage of the MTC terminal that is in a poor radio environment may be enhanced, thereby performing normal communication with a base station.

Abstract: Disclosed is a random access method for a machine type communication (MTC) terminal. The random access method performed by a terminal includes performing a cell search, determining a radio environment based on time taken to perform the cell search, and performing different random access procedures depending on the determined radio environment. Accordingly, coverage of the MTC terminal that is in a poor radio environment may be enhanced, thereby performing normal communication with a base station.

Abstract: A base station in a mobile communication system determines the number of slots that are to be used to transmit a synchronization signal in a period of the synchronization signal depending on the number of neighbor cells, allocates a synchronization signal region in which the synchronization signal is to be transmitted to a first slot of the determined number of slots depending on a cell identifier of a serving cell, and allocates a reserved region in which no signal is transmitted to slots other than the first slot among the determined number of slots so as to correspond to a position of the synchronization signal region.

Abstract: A method and apparatus for scheduling a beam in a mobile communication system are provided. A terminal receives signals through a plurality of switching beam directions, and receives a plurality of beams that are transmitted while performing beam switching in a transmission time interval (TTI) unit by a base station. The terminal selects a signal having largest intensity among received signals, and transmits an uplink scheduling request signal in a beam direction corresponding to the selected signal.