A method of transmission over multiple wireless channels in a multiple antenna system includes storing channel modulation matrices at a transmitter; receiving quantized channel state information at the transmitter from plural receivers; selecting a transmission modulation matrix using the quantized channel state information from the stored channel modulation matrices; and transmitting over the multiple channels to the plural receivers using the selected transmission modulation matrix. In another embodiment, the method includes storing, at one or more receivers, indexes of modulation matrices generated by a capacity enhancing algorithm; upon a selected one of the one or more receivers receiving a transmission from the transmitter, the selected receiver selecting a modulation matrix from the stored modulation matrices that optimizes transmission between the transmitter and the selected receiver, the selected receiver sending an index representing the selected modulation matrix; and receiving the index at the transmitter from the selected receiver.

In order to transmit a large amount of data in series at a time with a MIMO communication scheme while avoiding deterioration of decoding characteristics due to change over time by a channel matrix, a wireless communication system uses an open-loop type and a closed-loop type of MIMO communication modes in combination and switches to the open-loop MIMO communication mode in response to the information that the amount of data to be transmitted at a time has exceeded a predetermined amount of bits or a predetermined transmission time during data transmission under the closed-loop MIMO communication mode. By discontinuing useless closed-loop MIMO communication and switching to the open-loop MIMO communication mode that is better than Zero-forcing, the decoding characteristics are prevented from simply becoming deteriorated.

The present disclosure provides a CSI feedback method, a CSI feedback device and a CSI feedback system. The CSI feedback method includes steps of: configuring, by a network side device, a first downlink channel measurement pilot for a UE; and receiving, by the network side device, first PMI information fed back by the UE. The first PMI information is acquired by the UE based on measurement of the first downlink channel measurement pilot and second PMI information. A dimension represented by the first PMI information is different from a dimension represented by the second PMI information.

A method, and a device, for reporting channel state information (CSI) in a wireless local area network system are discussed. The method according to one embodiment includes receiving, by a responding station, a sounding Physical layer Protocol Data Unit (PPDU) from a requesting station; and transmitting, by the responding station, a CSI report to the requesting station, the CSI report including CSI report information in a form of angles representing a beamforming feedback matrix that is estimated by the responding station based on the sounding PPDU. If the sounding PPDU is received via a plurality of contiguous channels, the beamforming feedback matrix is estimated based on all of the plurality of contiguous channels. If the sounding PPDU is received via at least one of a plurality of non-contiguous channels, the beamforming feedback matrix is estimated based on only one of the plurality of non-contiguous channels.

When a terminal device receives a MAC CE indicating activation of a second cell in subframe n and an action of monitoring a PDCCH for a first cell is not applied in subframe n+8, an action related to CSI reporting for the second cell on a PUCCH is applied in a subframe that is no earlier than subframe n+8 and in which an action of monitoring the PDCCH for the first cell is applied. When the terminal device receives the MAC CE indicating activation of the second cell in subframe n, the action related to the CSI reporting for the second cell on the PUCCH is applied in subframe n+8, irrespective of whether the action of monitoring the PDCCH for the first cell is applied in subframe n+8.

A method of transmission over multiple wireless channels in a multiple antenna system includes storing channel modulation matrices at a transmitter; receiving quantized channel state information at the transmitter from plural receivers; selecting a transmission modulation matrix using the quantized channel state information from the stored channel modulation matrices; and transmitting over the multiple channels to the plural receivers using the selected transmission modulation matrix. In another embodiment, the method includes storing, at one or more receivers, indexes of modulation matrices generated by a capacity enhancing algorithm; upon a selected one of the one or more receivers receiving a transmission from the transmitter, the selected receiver selecting a modulation matrix from the stored modulation matrices that optimizes transmission between the transmitter and the selected receiver; the selected receiver sending an index representing the selected modulation matrix; and receiving the index at the transmitter from the selected receiver.

Some aspects described herein relate to receiving, from a sidelink transmitting user equipment (UE), one or more first transmissions over a first set of sidelink resources, receiving, from the sidelink transmitting UE, one or more second transmissions over a second set of sidelink resources, and transmitting, to the sidelink transmitting UE, second feedback for the one or more second transmissions in a second set of feedback resources, wherein the second feedback also includes, based on a failure associated with first feedback for the one or more first transmissions to be transmitted over a first set of feedback resources, a retransmission of at least a portion of the first feedback. Other aspects relate to receiving the second feedback with the retransmission of at least the portion of first feedback.

A method for sending a hybrid automatic repeat request (HARQ) includes receiving downlink data, generating HARQ feedback information based on the downlink data, and sending, based on a switching priority, the HARQ feedback information by using a first feedback mode or a second feedback mode. The first feedback mode is delayed feedback on a current carrier, the second feedback mode is feedback on a candidate carrier, and a terminal device supports switching between the first feedback mode and the second feedback mode.

Certain aspects of the present disclosure provide techniques for implicitly linking aperiodic channel state information (A-CSI) reports to CSI-reference signal (CSI-RS) resources. In an aspect, the UE may be instructed to report on specific CSI-RS resource(s) via explicit signaling in the UE grant. Other aspects disclose techniques for implicit CSI-RS resource selection by the UE that require fewer signaling resources. Instead of explicitly signaling CSI-RS resources to the UE, the UE may implicitly select CSI-RS resource for CSI feedback reporting based on information known to the UE, e.g. a subframe on which a reporting request is received. This may reduce the impact of the additional signaling in the UE grant.

Aspects of the disclosure provide a method for avoiding reselection of fake cell. The method includes transmitting a first request for network service of a wireless communication network in a first cell from user equipment, receiving a first reject message without integrity protection, adding the first cell to a set-aside cell list, and selecting a cell from other cells that are not included in the set-aside cell list to request network service.