Channel state information (CSI) can be transmitted to a network node incrementally to increase network efficiency. The CSI feedback framework can be enhanced by allowing a user equipment (UE) to report multiple sets of CSI feedback, where each set can comprise a rank indicator (RI), a pre-coder matrix indicator (PMI), and a channel quality indicator (CQI). Since a different set may have a different sub-band, the CSI feedback framework can support the sub-band rank, wherein rank data from a wideband and the sub-band can be used by the network.

Channel state information (CSI) can be transmitted to a network node incrementally to increase network efficiency. The CSI feedback framework can be enhanced by allowing a user equipment (UE) to report multiple sets of CSI feedback, where each set can comprise a rank indicator (RI), a pre-coder matrix indicator (PMI), and a channel quality indicator (CQI). Since a different set may have a different sub-band, the CSI feedback framework can support the sub-band rank, wherein rank data from a wideband and the sub-band can be used by the network.

A method of a user equipment (UE) in a wireless communication system is provided. The method comprises: receiving, from at least one base station (BS) of a group of (N) BSs, channel state information (CSI) configuration information including a number of uplink control information (UCI) parts for a CSI reporting; identifying the number of UCI parts for the CSI reporting; determining a CSI report based on the identified number of UCI parts; identifying one or more BSs in the group of (N) BSs to transmit the determined CSI report; and transmitting, to the one or more identified BSs, via an uplink channel, a UCI including the determined CSI report, wherein the UCI includes the identified number of UCI parts each of which includes a part of the determined CSI report.

A method of a user equipment (UE) in a wireless communication system is provided. The method comprises: receiving, from at least one base station (BS) of a group of (N) BSs, channel state information (CSI) configuration information including a number of uplink control information (UCI) parts for a CSI reporting; identifying the number of UCI parts for the CSI reporting; determining a CSI report based on the identified number of UCI parts; identifying one or more BSs in the group of (N) BSs to transmit the determined CSI report; and transmitting, to the one or more identified BSs, via an uplink channel, a UCI including the determined CSI report, wherein the UCI includes the identified number of UCI parts each of which includes a part of the determined CSI report.

Network equipment receives, from a User Equipment (UE), an indication that the network equipment is to transition to sparse reference signaling for the UE, and the network equipment then transmits the sparse reference signaling to the UE. The sparse reference signaling is consistent with a sparse signaling pattern, which is determined at the UE based on previous reference signaling previously transmitted to the UE or another UE. At a UE, the sparse reference signaling is received from network equipment, and channel measurement and prediction are performed based on the received sparse reference signaling.

This disclosure provides systems, methods, and apparatus for link adaptation in a wireless local area network (WLAN). A link adaptation test packet from a first WLAN device to a second WLAN device may be formatted as a multiple-input-multiple-output (MIMO) transmission and may include one or more test portions for link quality estimation of the MIMO transmission. A link quality estimation portion of the test packet may permit measurement of link quality for various spatial streams of the MIMO transmission. The link adaptation test packet may enable a fast rate adaptation of a communication link based on the impact of interference to the various spatial streams. The second WLAN device may provide feedback information regarding the one or more test portions. The feedback information may be used to determine a transmission rate for a subsequent transmission from the first WLAN device to the second WLAN device based on wireless channel conditions.

In a general aspect, a rate at which MIMO transmissions are elicited from wireless communication devices is varied. A first wireless communication device may be configured to wirelessly transmit a first set of messages at a first transmission rate to a second wireless communication device. The first wireless communication device may further be configured to receive MIMO transmissions from the second wireless communication device. The first wireless communication device may additionally be configured to generate first channel information based on respective training fields in each of the first MIMO transmissions; determine a rate at which the first channel information is generated; vary the first transmission rate to a second, different transmission rate based on the rate at which the first channel information is generated; and wirelessly transmit a second set of messages at the second transmission rate to the second wireless communication device.

A method in a wireless device for reporting Channel State Information (CSI). The wireless device is comprised in a wireless communications system. The method includes receiving a CSI process configuration and a request for CSI information from a network node. The method further includes reporting CSI for one or more CSI processes. The CSI reflects the state of the channel for a CSI reference resource. According to the method, the CSI reference resource is determined based on the number of configured CSI processes. Related devices are also disclosed.

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.

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.