A communication apparatus of the present disclosure includes a receiver which, in operation, receives a signal that includes a non-legacy preamble and a data field, the non-legacy preamble comprising a first field for indicating a number of spatial streams (Nss) in the data field and a second field for indicating one of a plurality of modulation and coding schemes (MCSs), wherein two or more frequency diversity transmission schemes are supported and one of the two or more frequency diversity transmission schemes is applied based on a value of the Nss; and circuitry which, in operation, decodes the signal.

A method according to an embodiment of the present invention, in which a terminal receives downlink control information from a base station in a wireless communication system comprises: a step of receiving information on an antenna port from the base station; a step of performing blind detection of a control channel on the basis of the information on the antenna port; and a step of obtaining downlink control information carried by the control channel through the blind detection, wherein it can be assumed that the information on the antenna port indicates the at least one antenna port to be monitored by the terminal among the plurality of antenna ports used by the base station for the control channel transmission, and the terminal while performing the blind detection applies a specific transmission diversity scheme to at least one antenna port indicated through the information on the antenna port. The terminal is capable of communicating with at least one of another terminal, a terminal related to an autonomous driving vehicle, the base station or a network.

The invention described herein presents a system and method to overcome the distortions and affectations introduced by the highly variant channels of one or several antennas both in the transmitter and in the receiver. Unlike any existing invention that operates under the same conditions, this device uses a completely new reception technique based on the concept of virtual trajectories in which iterative calculations or solution of linear systems in operating time are not required, thus saving a considerable amount of operations. The receiver of this device manages to convert the fast variations of the channel into virtual antennas, thus achieving a considerable increase in the signal to noise-interference ratio. The resulting performance in terms of noise immunity is much better than any technique found so far and also requires a much smaller amount of calculations in the receiver.

This invention is a transmission device capable of enhancing the reception characteristics of a terminal when employing transmit diversity using two antenna ports in an ePDCCH. In a base station (100) that transmits a reference signal to a terminal (200) using two antenna ports, a setting unit (102), on the basis of the reception quality of the terminal, sets as the aforementioned two antenna ports either a first antenna port pair for which DMRS (reference signals) do not undergo mutual code multiplexing, or a second antenna port pair for which the DMRS do undergo code multiplexing. A transmitter (109) transmits the DMRS from the two antenna ports set in the setting unit (102).

A communication apparatus includes circuitry and a transmitter. The circuitry maps a precoded downlink control signal to one of a plurality of mapping candidates. The precoded downlink control signal is prepared using a first precoding for single-antenna port transmission with a single antenna port in localized allocation mode. The precoded downlink control signal is prepared using a second precoding for multi-antenna ports transmission with two antenna ports in distributed allocation mode. The plurality of mapping candidates is comprised of a plurality of aggregation levels, and one or more of the aggregation levels that is higher than a boundary among the plurality of aggregation levels is associated with only the multi-antenna ports transmission, the boundary being determined based on signaling indicated from the base station apparatus. The transmitter transmits the precoded downlink control signal.

A transmission device that performs multiple-input multiple-output (MIMO) transmission of transmit data using a plurality of fundamental bands. The transmission device includes an error correction coding unit, a mapping unit, and a MIMO coding unit. The error correction coding unit, for each data block of predefined length, performs error correction coding and thereby generates an error correction coded frame. The mapping unit maps each predefined number of bits in the error correction coded frame to a corresponding symbol and thereby generates an error correction coded block. The MIMO coding unit performs MIMO coding with respect to the error correction coded block. Components of data included in the error correction coded block are allocated to at least two of the fundamental bands and transmitted.

An apparatus is configured to be employed within a base station. The apparatus comprises baseband circuitry which includes a radio frequency (RF) interface and one or more processors. The one or more processors are configured to generate control information, the control information including a configured number of ports; receive a plurality of sounding reference signals (SRS) via the RF interface from a user equipment (UE) device, wherein each of the plurality of SRS is associated with one of the one or more precoders; and generate a ranking of a the one or more precoders based on the received plurality of SRS, wherein the plurality of SRS are associated with the one or more precoders.

This application provides a data sending method, a data receiving method, a network device, and a terminal device, to obtain a diversity gain to a greater extent, improve received signal quality, and improve data transmission reliability. The method includes: performing, by a network device, transmit diversity preprocessing on one modulated symbol stream to obtain at least one transmit diversity spatial stream; performing, by the network device, precoder cycling on the at least one transmit diversity spatial stream to obtain at least one precoded data stream, where each of the at least one transmit diversity spatial stream corresponds to at least two different precoding vectors; and sending, by the network device, the at least one precoded data stream to a first terminal device.

Certain aspects of the present disclosure relate to methods and apparatus for updating beam information across a plurality of component carriers (CCs) via downlink control information (DCI).

Methods, systems, and devices for wireless communications are described. A satellite may determine one or more sets set of resources for conveying reference signals to a user terminal. In one example, the satellite may determine a set of resources that includes multiple resource groups each associated with a respective frequency range. In another example, the satellite may determine multiples sets of resources and each set of resources may include resources within respective frequency range. Upon determining the set(s) of resources, the satellite may transmit an indication of the set(s) of resources to a user terminal.