Wireless communications for a plurality of cell groups are described. Uplink transmissions, such as uplink transport blocks, hybrid automatic repeat request (HARQ) transmission, and/or channel state information transmission, may be based on one or more time alignment timers associated with a cell group.

Provided is a terminal apparatus including a display unit displaying an execution screen of a shared application, reflecting on a display operations performed by multiple users as operations performed on one application, where the shared application includes a function for displaying an identification object that associates each of the users with an operation result, displayed on the execution screen, reflecting the operation performed by each of the users, a function for setting, when a first user selects an identification object related to a second user and specifies a region on the screen, the specified region as a shared region that is shared by the first and second users, and a function for controlling, when the first or second user performs operation in the shared region, such that the displayed operation result reflecting the operation is not shown to users other than the first and second users.

The present invention relates to a wireless communication system. The method whereby a terminal receives synchronizing signals in a wireless communication system supporting multi-carriers, according to one embodiment of the present invention, comprises the steps of: receiving location information on domains, from which the synchronizing signals are transmitted, among the domains resulting from the division of the whole system bandwidth into N parts along a frequency axis and into M parts along a time axis (wherein N and M are natural numbers); and receiving the synchronizing signals from the domains corresponding to the location information, wherein the respective synchronizing signals transmitted to multiple carriers can be transmitted from domains having a different frequency and/or time.

A method and a device for transmitting and receiving a signal on the basis of multiple antennas are provided. A transmitting device may include a radio frequency (RF) module transmitting a quadrature amplitude modulation (QAM) signal of a first symbol corresponding to a hybrid frequency shift keying and quadrature amplitude modulation (FQAM) mode and transmitting a QAM signal of a second symbol corresponding to a QAM mode through a second antenna; and a modulation module mapping the QAM signal of the first symbol to one frequency tone among the preset number of frequency tones according to a frequency shift keying (FSK) signal of the first symbol and mapping the second symbol to the frequency tone to which the first symbol is mapped.

A method and a device for transmitting and receiving a signal on the basis of multiple antennas are provided. A transmitting device may include a radio frequency (RF) module transmitting a quadrature amplitude modulation (QAM) signal of a first symbol corresponding to a hybrid frequency shift keying and quadrature amplitude modulation (FQAM) mode and transmitting a QAM signal of a second symbol corresponding to a QAM mode through a second antenna; and a modulation module mapping the QAM signal of the first symbol to one frequency tone among the preset number of frequency tones according to a frequency shift keying (FSK) signal of the first symbol and mapping the second symbol to the frequency tone to which the first symbol is mapped.

Orthogonal Time Frequency Space (OTFS) is a novel modulation scheme with significant benefits for 5G systems. The fundamental theory behind OTFS is presented in this paper as well as its benefits. We start with a mathematical description of the doubly fading delay-Doppler channel and develop a modulation that is tailored to this channel. We model the time varying delay-Doppler channel in the time-frequency domain and derive a new domain (the OTFS domain) where we show that the channel is transformed to a time invariant one and all symbols see the same SNR. We explore aspects of the modulation like delay and Doppler resolution, and address design and implementation issues like multiplexing multiple users and evaluating complexity. Finally we present some performance results where we demonstrate the superiority of OTFS.

A hybrid data transmission frame format for a hybrid single-carrier modulation and OFDM carrier modulation MIMO system and corresponding transmission/reception methods and devices. A transmitter employs single-carrier modulation for preambles and signaling fields via a single-carrier signal generator to produce single-carrier transmission sequences of transmission links. While to employs the same sampling rate to process all the data so as to match a receiver,the sampling rate of the single-carrier transmission sequences needs to be processed into being identical to that of OFDM via a pulse shaping multiphase filter before entering a digital-to-analog converter; the transmitter employs an OFDM modulation mode to transmit data field segments via an OFDM signal generator; and a data receiving process of the receiver is opposite to a data transmitting process of the transmitter.

A hybrid data transmission frame format for a hybrid single-carrier modulation and OFDM carrier modulation MIMO system and corresponding transmission/reception methods and devices. A transmitter employs single-carrier modulation for preambles and signaling fields via a single-carrier signal generator to produce single-carrier transmission sequences of transmission links. While to employs the same sampling rate to process all the data so as to match a receiver,the sampling rate of the single-carrier transmission sequences needs to be processed into being identical to that of OFDM via a pulse shaping multiphase filter before entering a digital-to-analog converter; the transmitter employs an OFDM modulation mode to transmit data field segments via an OFDM signal generator; and a data receiving process of the receiver is opposite to a data transmitting process of the transmitter.

A system for switching between different communication modes by network nodes according to a time-division schedule to transmit and receive data packets is provided. For example, a transmitting node is configured to determine a scheduled communication mode of an upcoming time division according to a time-division schedule, and transmit a data packet in that time division when the scheduled communication mode matches a selected communication mode supported by both the transmitting node and a receiving node. The receiving node operates in a scheduled communication mode specified for a current time division by the time-division schedule and determines whether a header of the data packet is detected in the current time division. If not, the receiving node switches to a second scheduled communication mode specified for the subsequent time division by the time-division schedule to detect the header of the data packet in a subsequent time division.

There is provided a communication system in which a base station apparatus communicates with a terminal apparatus and a communication apparatus flexibly designed to address diverse use cases so as to significantly enhance the transmission efficiency of the system as a whole. The communication apparatus includes an acquisition section that acquires information from an apparatus in wireless communication, and a control section that selects either orthogonal multiple access communication or non-orthogonal multiple access communication for communication with the apparatus on the basis of the information acquired by the acquisition section.