The present disclosure relates to a mobile terminal, a base station and respective operation methods. The mobile terminal comprises circuitry, which in operation assumes that a base station is configured to use one of a plurality of transmission beams, receives a downlink control channel candidate and a corresponding demodulation reference signal using one of a plurality of reception beams corresponding to the assumed one of the plurality of transmission beams, performs channel estimation based on the received demodulation reference signal, and, depending on the quality, demodulates the downlink control channel candidate using the channel estimation. The channel estimation is performed using a demodulation reference signal sequence which is generated observing an association which is associating the generated sequence with the assumed one of the plurality of transmission beams such that at least two of the plurality of transmission beams are associated with different demodulation reference signal sequences.

According to an embodiment of the disclosure, a method of operating a user equipment (UE) for estimating a channel based on a physical uplink shared channel (PUSCH) transmitted repetitively may include receiving, from a base station (BS), repetitive transmission configuration information for repetitively transmitting a PUSCH; receiving, from the BS, frequency hopping configuration information including configuration information for a hopping interval between a plurality of frequency resources for transmitting the PUSCH; and repetitively transmitting the PUSCH to the BS while performing frequency hopping at the hopping interval based on the repetitive transmission configuration information and the frequency hopping configuration information.

Methods, systems, and devices for wireless communications are described. A first device may receive a first reference signal from a second device and may generate a channel status feedback message based on the first reference signal. The first device may bundle the second reference signal and the channel status feedback message and may transmit the second reference signal and the channel status feedback to the second device. The first device may initiate a data transfer with the second device based on transmitting the second reference signal and the channel status feedback message.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an apparatus of a user equipment (UE) may receive, from a base station, a physical downlink control channel (PDCCH) indicating a configuration for one or more of demodulation reference signal (DMRS) bundling that is to be used for channel estimation by the base station for a first group of physical uplink control channels (PUCCHs) or frequency hopping for a second group of PUCCHs. The apparatus may transmit, to the base station, one or more PUCCHs based at least in part on the configuration. Numerous other aspects are described.

A method for estimating a channel status by a base station in a wireless communication system according to an embodiment of the present invention comprises the steps of: obtaining an uplink channel matrix by using a sounding reference signal (SRS) received from a terminal; transmitting a channel state information-reference signal (CSI-RS) through at least some antenna devices in a two-dimensional antenna array of the base station; receiving a channel quality indicator (CQI) calculated on the basis of the CSI-RS transmission; and obtaining, through a predetermined correction factor obtained on the basis of the CQI and the uplink channel matrix, a downlink channel matrix for the entire two-dimensional antenna array comprising the remaining antenna devices through which the CSI-RS is not transmitted.

This disclosure describes systems, methods, and devices related to a trigger-based null data packet (NDP) for channel sounding system. A device may send a trigger frame to a group of station devices, the group of station devices including a first station device, the trigger frame indicating a high efficiency (HE) long training field (HE-LTF) mode and a guard interval duration. The device may identify a HE trigger-based (TB) null data packet (NDP) received from the first station device, the HE TB NDP including a first packet extension field, wherein the HE TB NDP is associated with the HE-LTF mode and the guard interval duration indicated in the trigger frame. The device may send a downlink NDP including a second packet extension field, a second HE-LTF mode, and a second guard interval duration. The device may determine channel state information based on HE TB NDP received from the first station device.

This disclosure discloses an information indication method and an apparatus, to resolve a problem that indication precision of an uplink precoding matrix is low. The method includes: receiving a downlink reference signal sent by a network device on a first transmission resource; performing channel estimation based on the downlink reference signal, to obtain a downlink equivalent channel corresponding to the first transmission resource; and determining, based on the downlink equivalent channel, to-be-indicated information corresponding to a terminal device, where the to-be-indicated information indicates an uplink precoding matrix used when a first terminal device sends uplink data on the first transmission resource. The downlink equivalent channel is obtained by performing channel estimation based on the downlink reference signal.

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may be configured with one or more parameters to support blockage detection for beamformed communication. The UE may receive a set of reference signals via a receive beam of a beam pair. The UE may detect a condition associated with a measured signal quality of a reference signal of the set of reference signals relative to a filtered signal quality of the set of reference signals. The condition may, in some examples, correspond to a drop of the measured signal quality at least a threshold amount below the filtered signal quality for at least a threshold duration of time. The UE may delete one or more signal quality values from a measurement database of the UE based on detecting the condition. The one or more signal quality values may be associated with the beam pair.

Provided is a radio communication device which can separate propagation paths of antenna ports and improve a channel estimation accuracy even when using virtual antennas. The device includes: a mapping unit which maps a data signal after modulation to a virtual antenna and a virtual antenna; a phase inversion unit which inverts the phase of S0 transmitted from an antenna port in synchronization with a phase inversion unit between the odd-number slot and the even-number slot; the phase inversion unit which inverts the phase of R0 transmitted from the antenna port; a phase inversion unit which inverts the phase of S1 transmitted from an antenna port in synchronization with a phase inversion unit; and the phase inversion unit which inverts the phase of R1 transmitted from an antenna port.

To facilitate positioning a user device, the user device is configured to measure, per an antenna array, reference signals received from transmission-reception points and to check, whether a downlink reference signal from a transmission-reception point is received in a serving antenna array and in one or more non-serving antenna arrays with a first delay. A non-serving antenna array receiving the signal with the first delay is an alternative antenna array to the serving antenna array. When the serving antenna array is under a maximum permissible exposure event, the user device is configured to select, which one of one or more alternative antenna arrays and the serving antenna panel is to be used for transmitting at least a positioning signal to the transmission-reception point.