The disclosure provides a method and a device for multi-antenna transmission in a base station and a User Equipment (UE). The UE, in turn, receives a first higher-layer signaling, monitors a first-type physical layer signaling in a first radio resource pool, and receives second downlink information in a second radio resource pool. The first higher-layer signaling is used for determining first information and second information, and the first information is used for multi-antenna related receiving in the first radio resource pool. The first-type physical layer signaling is detected, and the first-type physical layer signaling is used for multi-antenna related receiving in the second radio resource pool, or, the first-type physical layer signaling is not detected, and the second information is used for multi-antenna related receiving in the second radio resource pool. The second radio resource pool is related to the first radio resource pool.

The present invention relates to a method and a device for selecting a cell in a mobile communication system and, more particularly, to a method and a device for selecting a cell for transmitting data, by a base station, not only in a licensed frequency band but in an unlicensed frequency band. In order to achieve the described task, a method for configuring a cell of a base station in a mobile communication system according to an embodiment of the present invention comprises the steps of: connecting with a terminal through a first cell of a licensed band; transmitting, to the terminal, a message for configuring multiple second cells in an unlicensed band through the first cell; and monitoring the configured multiple second cells in the unlicensed band, wherein the number of the multiple second cells exceeds the number of cells, a Carrier Aggregation (CA) of which the terminal can support. The present disclosure relates to a 5G or a pre-5G communication system to be provided in order to support a higher data transmission rate after a 4G communication system such as an LTE.

The present invention relates to a wireless communication system. More specifically, as a method for transmitting data in a wireless communication system performing a CoMP operation by using a cache, a method for transmitting data, according to the present invention, can comprise the steps of: determining a transmission mode among a plurality of transmission modes on the basis of at least one piece of data stored in the cache; determining data to be transmitted in the transmission mode; and transmitting the data according to the determined transmission mode, wherein the transmission mode can comprise: a first mode for coordinately performing data transmission between coordinated base stations; a second mode for coordinately performing scheduling by sharing channel information between the coordinated base stations; and a third mode for combining the first mode and the second mode.

A first communication device determines one or more parameters related to a format of a media access control layer (MAC) data unit for an uplink (UL) multi-user (MU) transmission. The format of the MAC data unit for the UL MU transmission is different than a format of a MAC data unit for an UL single user (SU) transmission. The first communication device generates one or more data units that include the one or more parameters. The first communication device transmits the one or more data units to a plurality of second communication devices to inform the plurality of second communication devices of the format of the MAC data unit for UL MU transmissions by the plurality of second communication devices to the first communication device.

A method and system for optimizing the performance of spatial multiplexing techniques in MU-MIMO wireless systems comprising subsectors where the presence of significant correlation between antenna elements can impair the performance of MU-MIMO techniques. The proposed solution ensures optimum selection of a specific combination of transmit antenna elements and receive antenna elements that maximizes MU-MIMO performance.

A user equipment (UE) includes a transmit chain that includes multiple radio frequency transmitters, multiple power amplifiers and a front end (FE) through which signals are transmitted. To achieve a high power UE solution, aspects of the disclosure selectively combine two or more power amplifier outputs based on an expected power output of the UE. To synchronously combine the outputs, an output feedback signal from a feedback receiver is used to adjust a delay and a phase of one or more signals associated with the power amplifiers.

Methods, systems, and devices for wireless communication are described. The method may include transmitting a first synchronization signal in a set of beam directions during a first symbol period of a synchronization subframe and transmitting a second synchronization signal in another set of beam directions during a second symbol period of the synchronization subframe. The second set of beam directions may be spatially interleaved with the first set of beam directions. Additionally, the method may include monitoring a first and second set of beam directions during a first and second symbol period of a random access subframe, respectively. Additionally, the method may include receiving, from a base station, first and second synchronization signals in a synchronization subframe, decoding the first synchronization signal, and transmitting an access request based at least in part on the decoded first synchronization signal.

Provided are a base station apparatus, a terminal device, and a communication method that can realize a small cell network while reducing load on the terminal device, the small cell network including a small cell performing massive MIMO transfer. The base station apparatus of the present invention is a second base station apparatus included in a communication system in which a plurality of the second base station apparatuses capable of acquiring assistance information from a first base station apparatus communicates with a terminal device, the base station apparatus including a codebook that describes a plurality of linear filters, in which the same cell identification number as at least one of the other second base station apparatuses is configured, and a synchronization signal correlated with the cell identification number is transmitted on the basis of the plurality of linear filters after first precoding of the synchronization signal.

Techniques for antenna system with multiple transmit paths are described and may be implemented via a wireless device to adapt to a variety of different wireless scenarios. Generally, the described techniques provide a wireless device with the ability to connect to different access points of a wireless network, such as 4G LTE and 5G NR portions of an UTRAN New Radio—Dual Connectivity (EN-DC)-compliant network. In at least some implementations, the described techniques utilize four-antenna systems configured to utilize low frequency bands, such as LTE low-band and 5G NR low-band frequencies. Further, the described systems enable multiple wireless protocols (e.g., LTE and 5G NR) to be used concurrently and cooperatively, such as to provide 5G NR connectivity utilizing an LTE network infrastructure.

Certain aspects relate to methods and apparatus for wireless communication. Particularly, aspects relate to techniques for wireless communications by an apparatus including a receive processing chain configured to process frames of a first type obtained via an omnidirectional antenna and frames of a second type obtained via an antenna array, a detector configured to detect a preamble portion of a frame of the first type, and a processing system configured to switch an input path of the receive processing chain from the antenna array to the omnidirectional antenna after the detection. Other aspects relate to wireless communications by an apparatus including a processing system that generates a frame of a first type having an indication that the apparatus can switch between outputting omnidirectional frames and outputting beamforming frames for transmission independent of channel reservation signaling, and a first interface configured to output the frame of the first type for transmission.