Provided are methods and devices for transmitting/receiving downlink signals in a Wireless communication system. Carrier information is provided to user equipment, the carrier information including cell identifier information which indicates Whether a first cell identifier related to a first carrier operating on one resource block (RB) and a second cell identifier used for a cell-specific reference signal (CRS) on the first carrier are the same or different. If the second cell identifier is the same as the first cell identifier, the user equipment assumes that the number of antenna ports for the CRS on the first carrier is the same as the number of antenna ports for a reference signal defined for NB-IoT (reference signal for NB-IoT, NRS). If the second cell identifier is different from the first cell identifier, the carrier information further includes antenna port number information, and the user equipment assumes that the number of the antenna ports for the CRS is the same as the number of antenna ports based on the antenna port number information.

A method of transmitting a synchronization by a V-UE (vehicle user equipment) signal in a wireless communication system, includes generating a secondary synchronization signal for the V-UE, and transmitting the generated secondary synchronization signal for the V-UE only in subframe 5 among subframe 0 to subframe 9, wherein a secondary synchronization signal for a D2D (device-to-device) UE is transmitted only in the subframe 0 among the subframe 0 to the subframe 9.

Provided are methods and devices for transmitting/receiving downlink signals in a narrowband. A user equipment acquires a first cell identifier from a first carrier on which a narrowband synchronization signal (nSS) and a narrowband broadcast channel (nPBCH) are present. Carrier information for a second carrier on which the nSS and the PBCH are not present is provided to a user equipment. The user equipment receives downlink data on the second carrier based on the carrier information and a narrowband reference signal (NB-RS). The NB-RS is received based on the first cell identifier. Each of the first and second carriers operates in one resource block.

In one embodiment of the present invention, a method by which a terminal transmits a signal in a wireless communication system comprises the steps of: generating a sequence having a length of 63 and having a punctured central element; inserting one or more zeros among respective elements of the sequence and mapping the sequence to RE; and transmitting the mapped sequence, wherein the number of one or more zeros inserted among the respective elements of the sequence corresponds to (a repetition factor1), and zeros are additionally inserted such that the sequence is symmetrical with respect to the central element of the sequence, when the repetition factor is an even number.

A User Equipment and method for transmitting a random-access radio frequency (RF) signal by applying Asynchronous Coded Multiple Access (ACMA) in a communication system employing Orthogonal Frequency Division Multiplexing (OFDM) is described. The method including: encoding an information stream as OFDM symbols using a low rate Forward Error Correction (FEC) coding suitable for Successive Interference Cancellation (SIC) to form a payload; generating a burst, including symbols, by performing an inverse fast Fourier transform on a unique word (UW) multiplexed with the payload; and synchronizing a transmission of each of the symbols of the burst with consecutive symbol-start instants. The UW includes a plurality of Zadoff-Chu (ZC) like sequences disposed in a subset of consecutive symbol-start instants of the burst. A receiver detects burst arrival by searching for consecutive ZC-like sequences. Channel state estimation can be performed by using the UW with additional ZC-like sequences in the burst.

The present invention discloses a calibration method for parallel multi-channel wireless channel measurement and a calibration system thereof. The transmitting end and the receiving end are disconnected, and are respectively connected to the calibration receiving channel and the calibration transmitting channel, and the calibration receiving channel/calibration transmitting channel cooperates with a measurement channel in air interface measurement, to calibrate a channel response characteristic of the transmitting end and the receiving end. By means of the present invention, a current channel response characteristic between multiple channels can be online supervised in real time, so as to ensure that a measurement error because of an impact of mutual interference between multiple channels can be avoided in the channel measurement process.

Disclosed are methods and apparatus used in wireless communications. The methods and apparatus establish a codebook for use in sparse code multiple access (SCMA) encoded communications, in particular. The SCMA codebook is configured to set the codebook for at least one layer (i.e., a user) to include a constellation of points having a first grouping of constellation points located at first radial distance from an origin in a complex plane and a second grouping of constellation points located at a second radial distance from the origin. This codebook arrangement provides increased gains at receivers by optimizing the constellation shape to improve the distance between constellation points (i.e., SCMA codebook performance), and in particular more robust performance when encountering amplitude and phase misalignment in uplink (UL) multiple access.

A signal sending method, a signal receiving method, and a device. The signal sending method includes: generating synchronization signals, where the synchronization signals include a first synchronization signal and a second synchronization signal; and sending the synchronization signals, where the first synchronization signal and the second synchronization signal overlap in time domain, and within a time domain resource in which the first synchronization signal and the second synchronization signal overlap, there is an intersection set between a frequency domain resource corresponding to the first synchronization signal and a frequency domain resource corresponding to the second synchronization signal. In this way, frequency domain resources occupied by the synchronization signals may be reduced, thereby saving frequency domain resources for another data transmission process. In addition, the two synchronization signals may further share a part of the frequency domain resources, thereby improving resource utilization.

Providing for secondary synchronization encoding utilizing a primary synchronization channel (P-SCH)-related scrambling code is described herein. Scrambled secondary synchronization codes (SSCs) can be assigned to multiple base stations of a radio access network (RAN). By way of example, PSC-based scrambling codes can be created from a plurality of M-sequences generated from a common polynomial expression. Further, an SSC codebook is provided that selects sequence pairs of a sequence matrix for generating SSCs. Selection can be based on transmission characteristics of resulting SSCs, providing reduced interference in planned, semi-planned and/or unplanned mobile deployments.

The present disclosure relates to a communication method and system for converging a 5.sup.th Generation (5G) communication system for supporting higher data rates beyond a 4.sup.th-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 terminal in a wireless communication system is provided. The method includes identifying demodulation reference signal (DMRS) type information and DMRS symbol length information, identifying port number information for receiving a DMRS and receiving the DMRS based on the DMRS type information, the DMRS symbol length information and port number information, wherein the port number information indicates a port number for the terminal in DMRS information including parameters for code division multiplexing (CDM) group information, offset information, frequency-domain orthogonal cover code (OCC) information, and time-domain OCC information corresponding respectively to multiple port numbers, and wherein the DMRS information is defined per DMRS type.