Abstract: A contention-based resource allocation method and apparatus is provided for use in a low power Device-to-Device (D2D) communication. The resource allocation method of a Device-to-Device (D2D) terminal of the present disclosure includes selecting an available resource in a frame, monitoring to detect a signal is received while a backoff timer is running, and performing, when no signal is received on the available resource before expiry of the backoff timer, a D2D communication using the available resource.

Abstract: The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A method of a base station (BS) for transmitting a master information block (MIB) in a wireless communication network is provided.

Abstract: The present disclosure relates to a 5G or pre-5G communication system for supporting a higher data transmission rate beyond a 4G communication system such as LTE. The present disclosure provides a method for performing device to device (D2D) discovery by a user equipment (UE), which is out of the coverage area serviced by a base station, in a wireless communication network, the method comprising the operations of: receiving pre-configuration information for transmitting a discovery message; and transmitting the discovery message in a transmission resource determined on the basis of the pre-configuration information, wherein the pre-configuration information includes a list of pools for transmitting the discovery message, and the transmission resource is determined from the list of pools.

Abstract: The present disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as a long term evolution (LTE). A method for transmitting a device to device (D2D) discovery signal by a user equipment (UE) in a communication system supporting a D2D scheme is provided. The method includes determining transmission power for D2D discovery signal transmission, and transmitting a D2D discovery signal using the transmission power, wherein the transmission power is determined by considering a cell at which the D2D discovery signal is transmitted.

Abstract: The present disclosure relates to a pre-5G or 5G communication system to be provided for supporting higher data rates beyond a 4G communication system, such as Long Term Evolution (LTE). Disclosed are a method and an apparatus for performing interleaving by using an identical interleaving bit generation method in multiple interleavers included in a communication system. The present disclosure provides a method for interleaving an input bit sequence by an interleaver of a multiple access communication system. The method includes setting a common parameter used by multiple interleavers; setting a unique parameter for the interleaver in view of a correlation between bit sequences which are input to the multiple interleavers; and interleaving the input bit sequence by using prime-power depending on the common parameter and the unique parameter.

Abstract: The present disclosure relates to a 5th generation (5G) or pre-5G communication system for supporting a higher data rate in comparison to the 4G communication system, such as long term evolution (LTE). A method for a terminal to establish synchronization with another terminal in a network supporting device-to-device (D2D) communication is provided. The method includes scanning, at the terminal, for synchronization signals from at least one base station, acquiring, when a synchronization signal is received from a base station, synchronization with the base station based on the synchronization signal, measuring power of the synchronization signal received from the base station, and transmitting, when data to be transmitted are generated in idle mode and the received signal power is less than a received signal power, a synchronization signal as a synchronization relaying terminal.

Abstract: A method for determining a device-to-device (D2D) symbol having orthogonality maintained (hereinafter, a position of the D2D symbol having orthogonality maintained) between single carrier-frequency division multiple access (SC-FDMA) sub-carriers among physical uplink control channel (PUCCH)/D2D signals, a method for determining the power of the symbol having orthogonality maintained, and a method for transmitting additional information in accordance with selective power control is provided.

Abstract: The method is performed as a client device and includes receiving a first message that includes a first data usage value. The first message is formatted according to a respective format. After receiving the first message, the method further includes acquiring a data usage template corresponding to the respective format. The method further includes receiving a second message that includes a second data usage value. The second message is formatted according to the respective format. The method further includes parsing the second message according to the data usage template so as to obtain a second data usage value.

Abstract: The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A terminal includes a transceiver configured to transmit or receive signals, and a controller configured to determine whether a current subframe is a subframe in which the terminal has to monitor a PDCCH, in response to the current subframe not being the subframe, determine whether a discovery pool for the terminal exists, and when the discovery pool for the terminal exists, operate a D2D discovery operation in the current subframe.

Abstract: The present disclosure relates to a pre-fifth generation (5G) or 5G communication system to be provided for supporting higher data rates beyond fourth generation (4G) communication system such as long term evolution (LTE). A synchronization signal transmission/reception method for use in a device-to-device (D2D) communication system is provided.

Abstract: A soft demapping apparatus and method thereof includes a pre-processing unit to pre-process a reception signal obtained from a symbol representing bits. A candidate selection unit selects two candidates from among constellation points included in a constellation for each of the bits. A distance calculation unit calculates a Euclidean distance between the reception signal and the two candidates. A log-likelihood ratio (LLR) calculation unit calculates an LLR with respect to the bits based on the Euclidean distance between the reception signal and the two candidates.

Abstract: A method of performing a soft demapping, includes obtaining a signal from a symbol representing bits that is transmitted from a transmitter, and calculating a gradient of a reference line in a constellation for a bit based on a rotation angle and a channel state of the constellation. The method further includes selecting a candidate for each of lines that corresponds to a logic value of the bit from constellation points included in the constellation based on the signal and the gradient of the reference line, and calculating a log-likelihood ratio (LLR) of the bit based on the signal and the selected candidate for each of the lines.

Abstract: The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system rt to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). An apparatus and method for acquiring synchronization information through the transmission and reception of signals between devices for device to device (D2D) communication is provided. A method for a user equipment (UE) in a wireless communication system includes detecting a synchronization signal of another UE in a predetermined measurement gap. The method also includes transmitting a detected result of the synchronization signal to an evolved Node B (eNB). A start time point of the measurement gap in a first measurement gap period and a star(time point of the measurement gap in a second measurement gap period are different from each other.

Abstract: A synchronization method and an apparatus for Device-to-Device (D2D) communication in a User Equipment (UE) are provided. The method includes comparing a reception power of a signal received from an evolved Node B (eNB) with a first reference power, if the reception power is less than the first reference power, generating and transmitting a synchronization signal for D2D communication by operating as a synchronization reference UE, comparing the reception power of a signal received from the eNB with a second reference power, and if the reception power is greater than or equal to the first reference power and less than the second reference power, relaying a synchronization signal received from the eNB by operating as a synchronization relaying UE.

Abstract: The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A method for performing device-to-device (D2D) communication by an in-coverage user equipment (UE) in a cellular communication system is provided. The method includes receiving a scheduling grant through a downlink control channel from a base station (evolved Node B (eNB)) and transmitting a scheduling assignment (SA) message in an SA region of a D2D communication frame and data in a data region of the D2D communication frame, based on the scheduling grant, wherein the scheduling grant indicates a resource pattern for transmission (RPT) corresponding to a set of resource units or a subset of a resource unit in a time domain and a frequency domain that is used for transmission of the data.

Abstract: A method of controlling transmission power of a terminal performing device to device (D2D) communication in a wireless communication system, the method including receiving power control information corresponding to radio resources used for the D2D communication by the terminal from a base station, determining a first transmission power of the radio resources to be used for the D2D communication by the terminal among the radio resources, and transmitting data for the D2D communication with the determined first transmission power by using the radio resource to be used for the D2D communication by the terminal.

Abstract: A method for performing synchronization by a device in a device to device (D2D) communication system is provided. The method includes transmitting a first synchronization signal, and transmitting offset information indicating a time difference between a synchronization reference time of the first synchronization signal and a transmission time of the first synchronization signal.

Abstract: A contention-based resource allocation method and apparatus is provided for use in a low power Device-to-Device (D2D) communication. The resource allocation method of a Device-to-Device (D2D) terminal of the present disclosure includes selecting an available resource in a frame, monitoring to detect a signal is received while a backoff timer is running, and performing, when no signal is received on the available resource before expiry of the backoff timer, a D2D communication using the available resource.

Abstract: A method of performing a soft demapping, includes obtaining a signal from a symbol representing bits that is transmitted from a transmitter, and calculating a gradient of a reference line in a constellation for a bit based on a rotation angle and a channel state of the constellation. The method further includes selecting a candidate for each of lines that corresponds to a logic value of the bit from constellation points included in the constellation based on the signal and the gradient of the reference line, and calculating a log-likelihood ratio (LLR) of the bit based on the signal and the selected candidate for each of the lines.

Abstract: A soft demapping apparatus and method thereof includes a pre-processing unit to pre-process a reception signal obtained from a symbol representing bits. A candidate selection unit selects two candidates from among constellation points included in a constellation for each of the bits. A distance calculation unit calculates a Euclidean distance between the reception signal and the two candidates. A log-likelihood ratio (LLR) calculation unit calculates an LLR with respect to the bits based on the Euclidean distance between the reception signal and the two candidates.