Abstract: A method and apparatus for transmitting and receiving signal in communication system. A method of a base station includes: configuring frequency spreading sequences each of which corresponds to a transmission starting time point; configuring time spreading sequences each of which corresponds to a terminal; and transmitting information on the frequency spreading sequences and the time spreading sequences to a plurality of terminals, wherein one of the frequency spreading sequences and one of the time spreading sequences are assigned to each of the plurality of terminals.

Abstract: An operation method of a first communication node in a communication system includes receiving a signal from a second communication node; demodulating the signal to obtain LLR values; calculating a first codeword based on the LLR values; selecting error patterns from among all error patterns based on Hamming weights; generating second codewords by applying the first codeword to each of the selected error patterns; and determining a codeword having a highest similarity to the first codeword among the second codewords as an optimal codeword.

Abstract: An LDPC decoding method of a received signal including a plurality of received symbols is provided. A decoding apparatus selects a perturbation space in which perturbation is to be performed based on a code length of the received signal and a maximum number of perturbation rounds indicating a number of perturbation rounds that can be performed, and performs a perturbation round. The decoding apparatus performs perturbation on a corresponding received symbol among the plurality of received symbols in each perturbation round, and decodes the received signal on which the perturbation has been performed. The decoding apparatus determines that decoding is successful when there is a perturbation round in which a decoding result of the received signal satisfies a predetermined condition.

Abstract: Feedback methods for repetitive uplink transmissions in a communication system are disclosed. An operation method of a terminal may comprise receiving DL data #1 from a base station through a DL data channel #1; receiving DL data #2 from the base station through a DL data channel #2; and when each of a UL control channel #1 on which an HARQ response #1 for the DL data #1 is to be transmitted and a UL control channel #2 on which an HARQ response #2 for the DL data #2 is to be transmitted overlaps with a UL data channel assigned by the base station, transmitting the HARQ response #1 and the HARQ response #2 to the base station through the UL data channel. Therefore, the performance of the communication system can be improved.

Abstract: Disclosed are methods and apparatuses for transmitting and receiving data channels in a communication system. An operation method of a terminal in a communication system may comprise receiving, from a base station, resource allocation information of a plurality of physical uplink shared channels (PUSCHs) used for repetitive transmission of a same transport block (TB); identifying a position of each of the plurality of PUSCHs in a time domain based on the resource allocation information; and repeatedly transmitting the same TB to the base station at the position of each of the plurality of PUSCHs. Therefore, performance of the communication system can be improved.

Abstract: A method and apparatus for transmitting and receiving signal in communication system. A method of a base station includes: configuring frequency spreading sequences each of which corresponds to a transmission starting time point; configuring time spreading sequences each of which corresponds to a terminal; and transmitting information on the frequency spreading sequences and the time spreading sequences to a plurality of terminals, wherein one of the frequency spreading sequences and one of the time spreading sequences are assigned to each of the plurality of terminals.

Abstract: In a system supporting narrowband Internet of things (NB-IoT), a terminal maps an uplink reference signal to a plurality of resource elements in a scheduled resource allocation unit, and transmits the uplink reference signal mapped to the plurality of resource elements. Here, the scheduled resource allocation unit includes a first number of contiguous slots in a time domain and a second number of contiguous subcarriers in a frequency domain.

Abstract: An operation method of a first terminal in a communication system may comprise receiving, from a base station, a control message including information on a resource allocated for a transmission indicator used for identifying the first terminal among a plurality of terminals performing uplink transmission; transmitting the transmission indicator to the base station using the resource allocated for the transmission indicator; and after transmitting the transmission indicator, transmitting an uplink signal to the base station using a preconfigured resource without an uplink grant.

Abstract: An operation method of a terminal for uplink transmission in a communication network based on Internet of things (IoT) includes receiving a message including information on a resource pool for the uplink transmission from a base station included in the communication network; configuring an uplink resource for the uplink transmission based on the resource pool; transmitting a message including a transmission indicator indicating the uplink transmission to the base station based on a transmission indicator pool corresponding to the resource pool; and performing the uplink transmission through the uplink resource based on a plurality of parameters preconfigured for the uplink transmission.

Abstract: Provided are a communication method based on device's property and an apparatus for allocating a resource by using the method. Devices are classified based on the device's property and a signal including information based on the resource allocation to the devices is transmitted to the devices. Data are received from a device through the allocated resource. Here, the devices transmitting pilot signals including device data values corresponding to preset expected reference data information transmit data through the allocated resource.

Abstract: A base station infers a random access failure rate depending on a random access collision of terminals performing random access and controls a random access opportunity of a terminal that fails the random access by using the random access failure rate of each terminal. Also, information for the controlled random access opportunity is transmitted to the terminal that fails the random access.

Abstract: An operation method of a first terminal in a communication system may comprise receiving, from a base station, a control message including information on a resource allocated for a transmission indicator used for identifying the first terminal among a plurality of terminals performing uplink transmission; transmitting the transmission indicator to the base station using the resource allocated for the transmission indicator; and after transmitting the transmission indicator, transmitting an uplink signal to the base station using a preconfigured resource without an uplink grant.

Abstract: In a system supporting narrowband Internet of things (NB-IoT), a terminal maps an uplink reference signal to a plurality of resource elements in a scheduled resource allocation unit, and transmits the uplink reference signal mapped to the plurality of resource elements. Here, the scheduled resource allocation unit includes a first number of contiguous slots in a time domain and a second number of contiguous subcarriers in a frequency domain.

Abstract: A base station infers a random access failure rate depending on a random access collision of terminals performing random access and controls a random access opportunity of a terminal that fails the random access by using the random access failure rate of each terminal. Also, information for the controlled random access opportunity is transmitted to the terminal that fails the random access.

Abstract: A method for random access includes transmitting a preamble to a base station; receiving a first random access response (RAR) message of at least one RAR messages which is multiplexed by the base station based on the preamble from the base station; and transmitting a scheduled message based on the first RAR message to the base station, wherein the first RAR message is addressed to the terminal, an apparatus, and a method for supporting random access of the terminal are provided.

Abstract: Provided are a communication method based on device's property and an apparatus for allocating a resource by using the method. Devices are classified based on the device's property and a signal including information based on the resource allocation to the devices is transmitted to the devices. Data are received from a device through the allocated resource. Here, the devices transmitting pilot signals including device data values corresponding to preset expected reference data information transmit data through the allocated resource.

Abstract: A method of sending control information including selecting an available physical resource block (PRB) in a control subframe included in a D2D frame and sending the control information using the available PRB, and a terminal for realizing the method, are provided.

Abstract: Disclosed are a ship station communication apparatus and a ship station communication method that enable direct communication between adjacent ships as well as two-way communication between a ship station and a coast station without increasing a size of a ship station or costs. A ship station communication apparatus for communication between a ship station and another ship station and communication between the ship station and a coast station according to an exemplary embodiment of the present invention may include a first switch configured to switch an operation between a transmission unit of the ship station and a reception unit of the ship station; and a second switch configured to switch a frequency of the reception unit.

Abstract: Provided are a fixed station receiver for a Multi-Input Multi-Output (MIMO) communication system and an uplink adaptation method thereof. In the uplink adaptation method, a sounding reference signal (SRS) is received from a terminal including a plurality of transmission antennas. A complex channel matrix (H) corresponding to a channel response and a noise variance (?2) corresponding to a noise power is calculated from the sounding reference signal. A signal-to-interference and noise ratio (SINR) on each transmission symbol is calculated with reference to the complex channel matrix (H) and the noise variance (?2). A pre-coding matrix of the terminal is selected with reference to the signal-to-interference and noise ratio (SINR).

Abstract: Provided is a data transmission system for transmitting control information from a terminal to a base station. The terminal may multiplex the control information, and may transmit the multiplexed control information to the base station using a plurality of transmit antennas. The base station may receive the multiplexed control information and combine the control information. The base station may transmit data to the terminal using the control information.