Method and apparatus for transmitting and receiving channel state information—reference signal (CSI-RS)

This applicationis a reissue application of U.S. application Ser. No. 16/717,357, filed on Dec. 17, 2019, now U.S. Pat. No. 11,128,361, whichis a continuation of U.S. application Ser. No. 16/126,462, filed Sep. 10, 2018,now U.S. Pat. No. 11,101,863,which is a continuation of and claims priority under 35 U.S.C. § 120 to International application No. PCT/KR2018/008296, filed on Jul. 23, 2018, which claims the benefit of U.S. Provisional application No. 62/535,243 filed on Jul. 21, 2017, U.S. Provisional application No. 62/541,115 filed on Aug. 04, 2017 and U.S. Provisional application No. 62/554,586 filed on Sep. 6, 2017, the contents of which are all hereby incorporated by reference herein in their entirety.

The present disclosure relates to a wireless communication system and, more particularly, to a method for transmitting and receiving a channel state information (CSI)-reference signal (RS) and an apparatus supporting the same.

Mobile communication systems have been generally developed to provide voice services while guaranteeing user mobility. Such mobile communication systems have gradually expanded their coverage from voice services through data services up to high-speed data services. However, as current mobile communication systems suffer resource shortages and users demand even higher-speed services, development of more advanced mobile communication systems is needed.

The requirements of the next-generation mobile communication system may include supporting huge data traffic, a remarkable increase in the transfer rate of each user, the accommodation of a significantly increased number of connection devices, very low end-to-end latency, and high energy efficiency. To this end, various techniques, such as small cell enhancement, dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), supporting super-wide band, and device networking, have been researched.

The present disclosure is to provide a method of designing a reference signal (RS) (e.g., TRS) to be used for time/frequency tracking.

The present disclosure proposes a method of explicitly or implicitly providing configuration of a TRS.

It is to be understood that technical objects to be achieved by the present invention are not limited to the aforementioned technical object and other technical objects which are not mentioned herein will be apparent from the following description to one of ordinary skill in the art to which the present invention pertains.

The present disclosure provides a method of transmitting and receiving a control state information (CSI)-reference signal (RS) in a wireless communication system.

Specifically, a method performed by a base station includes: configuring control information indicating that an antenna port for all CSI-RS resources included in a CSI-RS resource set is same, wherein the CSI-RS resource set is used for tracking at least one of a time or a frequency; transmitting the configured control information to a user equipment (UE); and transmitting the CSI-RS to the UE through all the CSI-RS resources.

In the present disclosure, the antenna port may be 1-port

In the present disclosure, the UE may be a UE in a radio resource control (RRC) connected state.

In the present disclosure, the CSI-RS may be a periodic CSI-RS.

In the present disclosure, all the CSI-RS resources may be configured with a same periodicity.

In the present disclosure, all the CSI-RS resources may be configured in a single slot or multiple slots.

In the present disclosure, the multiple slots may be consecutive slots.

In the present disclosure, symbol locations of all the CSI-RS resources may be different when all the CSI-RS resources are configured in the single slot.

In the present disclosure, code division multiplexing (CDM) may not be applied to all the CSI-RS resources.

In the present disclosure, a frequency domain density of each of the CSI-RS resources may be greater than 1.

In the present disclosure, the CSI-RS resource set may not be configured both for the tracking and for beam management.

In the present disclosure, a CSI-RS resource used for the tracking may be quasi co-located (QCL) with a CSI-RS resource used for CSI acquisition, a CSI-RS resource used for beam management, or an SS/PBCH block (SSB).

In the present disclosure, a time domain measurement restriction for the CSI-RS may be set to “OFF”.

In the present disclosure, linkage between the CSI-RS resource set and a report setting may not be set.

In the present disclosure, linkage between the CSI-RS resource set and a specific report setting may be set.

In the present disclosure, the specific report setting may be a null reporting setting.

In the present disclosure, the method may further include receiving information related to a density of a time domain of the CSI-RS from the UE.

In the present disclosure, the time domain may be a single slot or consecutive slots.

In addition, in the present disclosure, a method for receiving a channel state information (CSI)-reference signal(RS) by a user equipment (UE) in a wireless communication system may include: receiving, from a base station, control information indicating that an antenna port for all CSI-RS resources included in a CSI-RS resource set is same, wherein the CSI-RS resource set is used for tracking at least one of a time or a frequency; receiving, from the base station, the CSI-RS through all the CSI-resources; and tracking at least one of a time or a frequency based on the received CSI-RS.

In addition, in the present disclosure, a base station which transmits a channel state information (CSI)-reference signal (RS) in a wireless communication system and includes: a radio frequency (RF) module configured to transmit and receive a wireless signal; and a processor functionally connected to the RF module and configured to: configure control information indicating that an antenna port for all CSI-RS resources included in a CSI-RS resource set is same, wherein the CSI-RS resource set is used for tracking at least one of a time or a frequency; transmit the configured control information to a user equipment (UE); and transmit the CSI-RS to the UE through all the CSI-RS resources.

The present disclosure newly defines a tracking reference signal (TRS) so as to more precisely perform time/frequency tracking of a user equipment (UE).

It will be appreciated by those skilled in the art that the effects that can be achieved with the present invention are not limited to what has been described above and other advantages of the present invention will be clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

Some embodiments of the present disclosure are described in detail with reference to the accompanying drawings. A detailed description to be disclosed along with the accompanying drawings is intended to describe some exemplary embodiments of the present disclosure and is not intended to describe a sole embodiment of the present disclosure. The following detailed description includes more details in order to provide full understanding of the present disclosure. However, those skilled in the art will understand that the present disclosure may be implemented without such more details.

In some cases, in order to avoid making the concept of the present disclosure vague, known structures and devices are omitted or may be shown in a block diagram form based on the core functions of each structure and device.

In the present disclosure, a base station has the meaning of a terminal node of a network over which the base station directly communicates with a terminal. In this document, a specific operation that is described to be performed by a base station may be performed by an upper node of the base station according to circumstances. That is, it is evident that in a network including a plurality of network nodes including a base station, various operations performed for communication with a terminal may be performed by the base station or other network nodes other than the base station. The base station (BS) may be substituted with another term, such as a fixed station, a Node B, an eNB (evolved-NodeB), a base transceiver system (BTS), or an access point (AP). Furthermore, the terminal may be fixed or may have mobility and may be substituted with another term, such as user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), a machine-type communication (MTC) device, a machine-to-Machine (M2M) device, or a device-to-device (D2D) device.

Hereinafter, downlink (DL) means communication from a base station to UE, and uplink (UL) means communication from UE to a base station. In DL, a transmitter may be part of a base station, and a receiver may be part of UE. In UL, a transmitter may be part of UE, and a receiver may be part of a base station.

Specific terms used in the following description have been provided to help understanding of the present disclosure, and the use of such specific terms may be changed in various forms without departing from the technical sprit of the present disclosure.

The following technologies may be used in a variety of wireless communication systems, such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and non-orthogonal multiple access (NOMA). CDMA may be implemented using a radio technology, such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented using a radio technology, such as global system for mobile communications (GSM)/general packet radio service (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented using a radio technology, such as Institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or evolved UTRA (E-UTRA). UTRA is part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) Long term evolution (LTE) is part of an evolved UMTS (E-UMTS) using evolved UMTS terrestrial radio access (E-UTRA), and it adopts OFDMA in downlink and adopts SC-FDMA in uplink. LTE-advanced (LTE-A) is the evolution of 3GPP LTE.

Embodiments of the present disclosure may be supported by the standard documents disclosed in at least one of IEEE 802, 3GPP, and 3GPP2, that is, radio access systems. That is, steps or portions that belong to the embodiments of the present disclosure and that are not described in order to clearly expose the technical spirit of the present disclosure may be supported by the documents. Furthermore, all terms disclosed in this document may be described by the standard documents.

In order to more clarify a description, 3GPP LTE/LTE-A is chiefly described, but the technical characteristics of the present disclosure are not limited thereto.

Definition of Terms

eLTE eNB: An eLTE eNB is an evolution of an eNB that supports a connection for an EPC and an NGC.

gNB: A node for supporting NR in addition to a connection with an NGC

New RAN: A radio access network that supports NR or E-UTRA or interacts with an NGC

Network slice: A network slice is a network defined by an operator so as to provide a solution optimized for a specific market scenario that requires a specific requirement together with an inter-terminal range.

Network function: A network function is a logical node in a network infra that has a well-defined external interface and a well-defined functional operation.

NG-C: A control plane interface used for NG2 reference point between new RAN and an NGC

NG-U: A user plane interface used for NG3 reference point between new RAN and an NGC

Non-standalone NR: A deployment configuration in which a gNB requires an LTE eNB as an anchor for a control plane connection to an EPC or requires an eLTE eNB as an anchor for a control plane connection to an NGC

Non-standalone E-UTRA: A deployment configuration an eLTE eNB requires a gNB as an anchor for a control plane connection to an NGC.

User plane gateway: A terminal point of NG-U interface

General System