TECHNICAL FIELD

The present disclosure relates generally to wireless communication systems and more specifically to channel state information (CSI) reporting in wireless communication systems.

BACKGROUND

Understanding and correctly estimating the channel between a user equipment (UE) and a base station (BS) (e.g., gNode B (gNB)) is important for efficient and effective wireless communication. In order to correctly estimate the DL channel conditions, the gNB may transmit a reference signal, e.g., CSI-RS, to the UE for DL channel measurement, and the UE may report (e.g., feedback) information about channel measurement, e.g., CSI, to the gNB. With this DL channel measurement, the gNB is able to select appropriate communication parameters to efficiently and effectively perform wireless data communication with the UE.

SUMMARY

Embodiments of the present disclosure provide methods and apparatuses to enable channel state information (CSI) reporting in a wireless communication system.

In one embodiment, a UE for CSI reporting in a wireless communication system is provided. The UE includes a transceiver configured to receive, from a base station (BS), CSI feedback configuration information. The UE further includes a processor operably connected to the transceiver. The processor is configured to: determine, based on the CSI feedback configuration information, the CSI feedback including, for each layer l of a total number of v layers, an indicator i1,8,lindicating an index of a strongest coefficient among KNZ,lcoefficients, wherein l∈{1, . . . , v} is a layer index, v≥1 is a rank value, and KNZ,lis a number of non-zero coefficients for layer l; and determine a payload of the indicator i1,8,lfor each layer l based on the rank value. The transceiver is further configured to transmit, to the BS, over an uplink (UL) channel, the CSI feedback including the indicator i1,8,lfor each layer l of the total number of v layers.

In another embodiment, a BS in a wireless communication system is provided. The BS includes a transceiver configured to: transmit channel state information (CSI) feedback configuration information to a user equipment (UE); and receive, from the UE, CSI feedback including an indicator i1,8,lindicating an index of a strongest coefficient among KNZ,lcoefficients for each layer l of a total number of v layers, wherein l∈{1, . . . , v} is a layer index, v≥1 is a rank value, KNZ,lis a number of non-zero coefficients for layer l, and a payload of the indicator i1,8,lfor each layer l is based on the rank value. The BS further includes a processor operably coupled to the transceiver. The processor is configured to: generate the CSI feedback configuration information; and use the indicator i1,8,lto obtain the strongest coefficient among the KNZ,lcoefficients for each layer l of the total number of v layers.

In yet another embodiment, a method for operating a UE is provided. The method comprises: receiving, from a base station (BS), channel state information (CSI) feedback configuration information; determining, based on the CSI feedback configuration information, CSI feedback including, for each layer l of a total number of v layers, an indicator i1,8,lindicating an index of a strongest coefficient among KNZ,lcoefficients, wherein l∈{1, . . . , v} is a layer index, v≥1 is a rank value, and KNZ,lis a number of non-zero coefficients for layer l; determining a payload of the indicator i1,8,lfor each layer l based on the rank value; and transmitting, to the BS, over an uplink (UL) channel, the CSI feedback including the indicator i1,8,lfor each layer l of the total number of v layers.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both direct and indirect communication. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

