A method for a user equipment (UE) is disclosed. The method includes receiving, by the UE, downlink control information (DCI) for a downlink (DL) scheduling assignment (DL-DCI), the DL-DCI indicating a first uplink (UL) carrier associated with a Physical Uplink Control Channel (PUCCH) resource configuration for transmitting an aperiodic UL transmission for uplink control information (UCI), and transmitting, by the UE, the aperiodic UL transmission for UCI in a second UL carrier without a PUCCH resource configuration, where the UE determines a resource allocation of the second UL carrier based on the DL-DCI. The DL-DCI includes at least one of: a UL/supplementary UL (SUL) carrier indicator, a Hybrid Automatic Repeat reQuest (HARQ)-ACK resource indicator (ARI), a sounding reference signal (SRS) request field, a HARQ timing indicator, or a channel station information (CSI) request.

Techniques and examples of layer mapping, channel state information (CSI) feedback and hybrid automatic repeat request (HARQ) feedback in mobile communications are described. A user equipment (UE) receives from a base station one or more reference signals, which may be non-zero power (NZP) or zero power (ZP), on one or more time-frequency resources indicated by a network via a communication link between the UE and the base station. The UE estimates, based on the receiving, a subspace spanned by a channel response of an interfering signal. The UE determines a precoding matrix indicator (PMI) based on the estimated subspace. The UE transmits to the base station a channel state information (CSI) feedback comprising at least the PMI. The PMI may include at least a first precoder and a second precoder.

A method for wireless communication by a terminal, a method for wireless communication by a base station, the terminal, and the base station, are provided. The method for wireless communication by the terminal includes receiving first information comprising a muting subframe interval, a subframe offset, and a muting position of a resource element in a resource block, checking presence of a data in a subframe, determining the resource element to be muted in the subframe based on the muting subframe interval, the subframe offset, and the muting position, if the data is present, and receiving the data on a physical downlink shared channel (PDSCH) based on the result of the determining step.

In a closed-loop wireless communication system, a codebook-based feedback mechanism is provided to enable non-unitary precoding for multi-stream transmission, where each stream is optimized with suitable transmission power allocation and AMC. The codebook-based feedback mechanism uses a precoding codebook having a power allocation matrix which is constrained to specify that beamforming always applies full power to a predetermined beam. With this constraint, a one-bit power allocation feedback index may be used to switch between beamforming and spatial multiplexing.

A space-time line coding system includes: in multiple antenna communication configured by at least one transmission antenna and at least two reception antennas, a transmitting end which encodes two information symbols using channel state information and sequentially transmits two encoded information symbols to a receiving end using the at least one transmission antenna; and a receiving end which receives two encoded information symbols using at least the two reception antennas and combines the received signals without channel state information.

Apparatuses, systems, and methods for a wireless device to encode channel state information (CSI), e.g., enhanced type II CSI. A common frequency basis may be selected. Spatial-frequency coefficients, frequency basis related information, and/or spatial basis related information may be determined. At least a portion of the coefficients and/or information may be encoded in a CSI report.

A radio terminal (12) transmits, to a radio access network (RAN) node (11) in a radio access network (RAN), an indication indicating whether a measurement gap for inter-bandwidth part (BWP) measurement among BWPs included in a plurality of downlink BWPs is required. The downlink BWPs are included within one system bandwidth. Further, the radio terminal (12) receives, from the RAN node (11), a measurement configuration including a measurement gap configuration for one or more BWPs included in the downlink BWPs. It is thus, for example, possible to allow a radio terminal to be configured with a proper measurement gap for inter-BWP measurement within one carrier bandwidth.

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive a message indicating, for each or multiple partial bands, a set of possible channel state information reference signal (CSI-RS) configurations. The UE may further receive downlink control information (DCI) from a base station, which may indicate a set of downlink resource associated with a first partial band. The UE may select a first CSI-RS configuration from the set of possible CSI-RS configurations for the first partial band based on the DCI, and when the base station transmits CSI-RS, the UE may obtain CSI-RS measurements over the first partial band during the set of downlink resources using the selected first CSI-RS configuration.

In a closed-loop wireless communication system, a codebook-based feedback mechanism is provided to enable non-unitary precoding for multi-stream transmission, where in each stream is optimized with suitable transmission power allocation and AMC. The codebook-based feedback mechanism uses a precoding codebook having a power allocation matrix which is constrained to specify that beamforming always applies full power to a predetermined beam. With this constraint, a one-bit power allocation feedback index may be used to switch between beamforming and spatial multiplexing.

An apparatus reports feedback messages for channel state information estimation with respect to a channel between a first antenna of a first device and a second antenna of a second device. The apparatus is configured to determine a frequency response across a predetermined bandwidth of the channel between the first antenna and the second antenna, sample a phase of the determined frequency response in order to obtain a number of samples of the phase of the determined frequency response, and send to a further apparatus at least a first feedback message including information of at least a subset of the obtained samples.