Exemplary embodiments of the present invention relates to an apparatus and method for performing periodic CSI reporting available in a system supporting a TDD-FDD aggregation operation and an FDD-TDD aggregation operation. A periodicity and an offset for periodic reporting of channel quality indicator and precoding matrix inidcator may be determined based on the cell type of a primary serving cell for a TDD-FDD carrier aggregation and an FDD-TDD carrier aggregation.

The present invention discloses an uplink data transmission method and device configured to shorten RTT in a transmission condition having a short time slot, thus reducing a user-plane latency and improving the system performance. An embodiment of the present invention provides an uplink data transmission method. The method comprises: determining, by the network side, a time slot size for data transmission, and sending, according to the time slot size, uplink scheduling signaling to a user equipment (UE); and receiving, by the network side and according to a predetermined scheduled timing, uplink data sent by the UE, wherein the time slot is a time unit having a duration smaller than 1 ms, and the predetermined scheduled timing is that when the network side employs a time slot n to send the uplink scheduling signaling, the network side receives the uplink data sent by the UE in a time slot (n+1), with lL, n and l both being integers greater than or equal to zero, and L denoting the set of selectable values of l.

A method for receiving a CSI-RS by a terminal in a wireless communication system according to an aspect of the present invention may comprise the steps of: receiving, from a base station, CSI-RS configuration information about a CSI-RS configuration to which the CSI-RS is mapped, wherein the CSI-RS configuration corresponds to merging of a plurality of legacy CSI-RS configurations, and the plurality of legacy CSI-RS configurations are mapped to a plurality of antenna ports numbered by corresponding legacy CSI-RS port numbers; and receiving the CSI-RS from the base station through the plurality of antenna ports on the basis of the CSI-RS configuration information.

An example system comprises a first antenna and a modem. The first antenna is configured to receive a signal from a transmitting radio frequency unit. The signal includes data and a known sequence. The modem is configured to retrieve the known sequence from the signal, transform the known sequence and the data into a frequency domain, calculate averages of groups of neighboring frequency points in the frequency domain to reduce the effect of nonlinear noise in the signal, the neighboring frequency points corresponding to the preamble in the frequency domain, compare the calculated averages to an expected frequency response in the frequency domain, determine a correction filter to apply to the data based on the comparison, apply the correction filter on the data in the frequency domain to create corrected data, transform the corrected data from the frequency domain to the time domain, and provide the data.

A method for a transmission-side device to transmit a signal in a wireless communication system is disclosed. To this end, the transmission-side device forms a multiplexed block by multiplexing a primary synchronization signal (PSS), a secondary synchronization signal (SSS) and a physical broadcast channel (PBCH) signal in time and frequency domains, wherein the PSS and the SSS form a synchronization signal (SS) by being multiplexed by the time-division multiplexing (TDM) method, and the SS and PBCH signals form the multiplexed block by being multiplexed by the TDM or frequency-division multiplexing (FDM) method.

A method for performing downlink transmissions from a transmitting device to multiple user devices using transmission resources from a multi-dimensional grid of resources is described. The method includes logically partitioning the transmission resources into multiple segments, assigning, to a given user device of the multiple user devices, transmission resources of one or more of the multiple segments, and performing, using at least some of the assigned transmission resources for the given user device, a downlink transmission using an orthogonal time frequency space (OTFS) transformation on data or signals to be transmitted to the given user device.

A method for performing downlink transmissions from a transmitting device to multiple user devices using transmission resources from a multi-dimensional grid of resources is described. The method includes logically partitioning the transmission resources into multiple segments, assigning, to a given user device of the multiple user devices, transmission resources of one or more of the multiple segments, and performing, using at least some of the assigned transmission resources for the given user device, a downlink transmission using an orthogonal time frequency space (OTFS) transformation on data or signals to be transmitted to the given user device.

Devices, systems and methods for high-utilization low-latency multi-channel time-division multiplexing access (TDMA) are described. One example method for wireless communication includes performing, in a first time interval of a time-division multiple access (TDMA) slot, a transmission of a first data unit over a first logical channel of the plurality of logical channels, refraining from transmitting, subsequent to a completion of the transmission of the first data unit, for a second time interval immediately after the first time interval, and performing (N?1) transmissions in (N?1) time intervals for each data unit of (N?1) subsequent data units in the TDMA slot, such that a transmission of an nth data unit of the (N?1) subsequent data units is performed over an nth logical channel of the plurality of logical channels.

A communication apparatus includes a receiver, a combiner, and a transformer. The receiver receives signals mapped on plural frequency bands. A size of at least one of the frequency bands is a multiple of a product of two or more powers of prime numbers, which are integer numbers greater than 1 and are different from each other. An exponent for at least one of the prime numbers is an integer greater than 1. The combiner combines the received signals into a combined signal. The transformer transforms the combined signal in a frequency domain into a symbol sequence in a time domain with an inverse discrete Fourier transform (IDFT) having a size that is a product of powers of plural values. The values are integer numbers greater than 1 and are different from each other. An exponent for at least one of the values is an integer greater than 1.

An example of a channelizer includes a plurality of receiver circuits, an individual receiver circuit including a frequency demultiplexer that is configured to demultiplex a plurality of subchannels and a time-division demultiplexer coupled to the frequency demultiplexer, the time-division demultiplexer configured to time-division demultiplex the plurality of subchannels to provide a plurality of time-division outputs, an individual time-division output including portions of data from each of the plurality of subchannels; and a plurality of switch circuits, each configured to receive a different time-division output of the plurality of time-division outputs from the individual receiver.