EP-4738720-A1 - METHOD AND APPARATUS FOR BEAM MANAGEMENT IN COMMUNICATION SYSTEM HAVING EXTRA-LARGE SCALE MULTIPLE INPUT AND MULTIPLE OUTPUT

EP4738720A1EP 4738720 A1EP4738720 A1EP 4738720A1EP-4738720-A1

Abstract

A method of a terminal according to the present disclosure comprises the steps of: transmitting a first signal including a terminal beam index and a first RS for each beam to a base station by beam sweeping terminal beams; receiving scatterer information existing on a communication path between the terminal and the base station from the base station; receiving information on the number of estimation steps for antenna estimation from the base station; performing a first procedure of hierarchically estimating, for each scatterer included in the scatterer information and the base station, VRs among antennas of the base station as many as the information on the number of estimation steps; and performing a second procedure for determining a base station beam to be used by the base station and each VR.

Inventors

LEE, JEONG SU
HONG, UI HYUN
SUH, YOUNG KIL
HAHN, GENE BACK
CHOI, WAN
KWON, Jeonghyeon
KIM, DONG HWI

Assignees

Hyundai Motor Company
Kia Corporation
Seoul National University R&DB Foundation

Dates

Publication Date: 20260506
Application Date: 20240628

Claims (20)

A method of a terminal, comprising: transmitting, to a base station, a first signal including a terminal beam index for each beam and a first reference signal (RS) by performing beam sweeping of terminal beams; receiving, from the base station, information on scatterer(s) existing on a communication path between the terminal and the base station; receiving, from the base station, information on a number of estimation stages for antenna estimation; performing, with the base station, a first procedure of hierarchically estimating visibility regions (VRs) of antennas of the base station by the number of estimation stages for each scatterer of the scatterer(s); and performing, with the base station, a second procedure of determining base station beams to be used in each of the VRs, wherein the information on the scatterer(s) includes a scatterer identifier and a terminal beam index corresponding to each scatterer.
The method of claim 1, further comprising: transmitting information on a service to be provided to the terminal and VR-related information to the base station after receiving the information on the scatterer(s).
The method of claim 2, wherein the VR-related information includes at least one of information on whether hierarchical VR estimation is supported, or information on a number of beams that the terminal is capable of forming simultaneously.
The method of claim 1, wherein the first procedure further comprises: receiving, from the base station, an RS transmission instruction through a terminal beam corresponding to at least one scatterer of the scatterer(s); and transmitting RS based on the RS transmission instruction.
The method of claim 4, wherein the RS transmission instruction includes at least one of a periodicity of transmitting the RS, a time of transmitting the RS, or a number of transmissions of the RS.
The method of claim 1, wherein the second procedure further comprises: receiving, from the base station, an RS transmission instruction through a terminal beam corresponding to at least one scatterer of the scatterer(s); transmitting a second signal including a second RS based on the RS transmission instruction; receiving, from the base station, a reference signals received power (RSRP) measurement reporting instruction message including terminal beam information; measuring an RSRP of an RS received from the base station through a terminal beam indicated by the terminal beam information; and reporting the measured RSRP to the base station.
The method of claim 1, wherein the base station has an extra-large scale multiple input multiple output (XL-MIMO) antenna, and each of the scatterer(s) includes at least one or more of a building, a vehicle, a person, a structure, an intelligent reflecting surface (IRS), a reconfigurable intelligent surface (RIS), or particles in the air.
A method of a base station, comprising: receiving, through beam sweeping over an entire antenna array of an extra-large scale multiple input multiple output (XL-MIMO) antenna, a first signal including a reference signal (RS) from a terminal; measuring a first reference signals received power (RSRP) of the first signal to acquire information on scatterer(s); transmitting the information on the scatterer(s) to the terminal; determining a number of estimation stages for XL-MIMO antenna estimation; transmitting information on the determined number of estimation stages to the terminal; performing a first procedure of hierarchically estimating visibility regions (VRs) of the XL-MIMO antenna by the number of estimation stages for each scatterer of the scatterer(s); and performing a second procedure of determining base station beams to be used with the terminal in one or more VRs, wherein the information on the scatterer(s) includes a scatterer identifier and a terminal beam index corresponding to each scatterer.
The method of claim 8, further comprising receiving information on a service of the terminal and VR-related information from the terminal after transmitting the information on the scatterer(s).
The method of claim 9, wherein the VR-related information includes at least one of information on whether hierarchical VR estimation is supported, or information on a number of beams that the terminal is capable of forming simultaneously.
The method of claim 8, wherein the first procedure further comprises: determining a number of estimation stages of the VRs; and performing a third procedure for VR determination on an entire array of the XL-MIMO antenna by the determined number of estimation stages, wherein the number of estimation stages of the VRs is determined based on at least one of a latency requirement received from the terminal or a number of antenna ports that the base station is capable of using transmission and reception simultaneously.
The method of claim 11, wherein the third procedure comprises, for each scatterer: dividing the entire array of the XL-MIMO antenna into a predetermined number of first antenna regions; selecting first representative antennas for the divided first antenna regions, respectively; measuring second RSRPs of RSs received from the terminal through the first representative antennas; determining first antenna region(s) including the first representative antennas having the second RSRPs exceeding a preset first threshold as VR candidate region(s); dividing each of the VR candidate region(s) into a predetermined number of second antenna regions; selecting second representative antennas for the divided second antenna regions, respectively; measuring third RSRPs of RSs received from the terminal through the second representative antennas; and determining second antenna region(s) including the second representative antennas having the third RSRP exceeding a preset second threshold as a VR.
The method of claim 8, wherein the second procedure further comprises, for each scatterer: transmitting an RS transmission instruction message through a terminal beam corresponding to each scatterer; measuring fourth RSRPs of RSs received from the terminal through antennas of the VR; determining a scatterer-VR combination based on the measured fourth RSRPs; and performing a fourth procedure of determining a subdivided beam to communicate with the terminal based on the determined scatterer-VR combination.
The method of claim 13, wherein the fourth procedure further comprises: transmitting information on the determined scatterer-VR combination to the terminal; subdividing each of base station beams to be transmitted through the VRs into a predetermined number of beams; transmitting, to the terminal, an RSRP measurement reporting instruction message including terminal beam information; determining combinations composed of pairs of subdivided beams of different VRs; transmitting RSs to the terminal through beams based on the combinations composed of the pairs of subdivided beams; receiving, from the terminal, an RSRP reporting message corresponding to the beams based on the combinations composed of the pairs of subdivided beams; and determining a base station beam among the subdivided beams based on the received RSRP reporting message.
A terminal comprising at least one processor, wherein the at least one processor is configured to: transmit, to a base station, a first signal including a terminal beam index for each beam and a first reference signal (RS) by performing beam sweeping of terminal beams; receive, from the base station, information on scatterer(s) existing on a communication path between the terminal and the base station; receive, from the base station, information on a number of estimation stages for antenna estimation; perform, with the base station, a first procedure of hierarchically estimating visibility regions (VRs) of antennas of the base station by the number of estimation stages for each scatterer of the scatterer(s); and perform, with the base station, a second procedure of determining base station beams to be used in each of the VRs, wherein the information on the scatterer(s) includes a scatterer identifier and a terminal beam index corresponding to each scatterer.
The terminal of claim 15, wherein the at least one processor is further configured to transmit information on a service to be provided to the terminal and VR-related information to the base station after receiving the information on the scatterer(s).
The terminal of claim 16, wherein the VR-related information includes at least one of information on whether hierarchical VR estimation is supported, or information on a number of beams that the terminal is capable of forming simultaneously.
The terminal of claim 15, wherein the at least one processor is further configured, during the first procedure, to: receive, from the base station, an RS transmission instruction through a terminal beam corresponding to at least one scatterer of the scatterer(s); and transmit RS based on the RS transmission instruction.
The terminal of claim 18, wherein the RS transmission instruction includes at least one of a periodicity of transmitting the RS, a time of transmitting the RS, or a number of transmissions of the RS.
The terminal of claim 15, wherein the at least one processor is further configured, during the second procedure, to: receive, from the base station, an RS transmission instruction through a terminal beam corresponding to at least one scatterer of the scatterer(s); transmit a second signal including a second RS based on the RS transmission instruction; receive, from the base station, a reference signals received power (RSRP) measurement reporting instruction message including terminal beam information; measure an RSRP of an RS received from the base station through a terminal beam indicated by the terminal beam information; and report the measured RSRP to the base station.

Description

[Technical Field] The present disclosure relates to an enhanced communication technique, and more particularly, to a technique for beam management in a communication system based on extra-large scale multiple input multiple output (XL-MIMO). [Background Art] A communication network (e.g., 5G communication network or 6G communication network) is being developed to provide enhanced communication services compared to the existing communication networks (e.g., long term evolution (LTE), LTE-Advanced (LTE-A), etc.). The 5G communication network (e.g., New Radio (NR) communication network) can support frequency bands both below 6GHz and above 6GHz. In other words, the 5G communication network can support both a frequency region 1 (FR1) and/or FR2 bands. Compared to the LTE communication network, the 5G communication network can support various communication services and scenarios. For example, usage scenarios of the 5G communication network may include enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), and the like. The 6G communication network can support a variety of communication services and scenarios compared to the 5G communication network. The 6G communication network can meet the requirements of hyper-performance, hyper-bandwidth, hyper-space, hyper-precision, hyper-intelligence, and/or hyper-reliability. The 6G communication network can support diverse and wide frequency bands and can be applied to various usage scenarios such as terrestrial communication, non-terrestrial communication, sidelink communication, and the like. Meanwhile, a 5G communication system serves a plurality of terminals simultaneously and employs a massive multiple-input multiple-output (MIMO) system to achieve higher data transmission rates. When a base station utilizes a massive MIMO system, it can achieve not only a higher data transmission rate for the terminal but also low inter-user interference and high energy efficiency by concentrating a beam on a specific location. When Frequency Range 2 (FR2) used in the 5G system and/or higher frequency bands expected to be used in a 6G system are used, a transmission signal is subject to a reduction in communication coverage due to high path attenuation. As one method to compensate for the problem of reduced communication coverage, a massive MIMO system may be used. Although the current massive MIMO system has the above-described advantages, the system has a limitation that it is difficult to obtain a sufficient spatial dimension because a very large number of antennas are deployed and used in a narrow space. A future 6G communication system is considering a form in which a large number of antennas are deployed on wide walls of buildings such as airports, shopping malls, and stadiums in order to obtain additional spatial dimensions beyond the massive MIMO system. A system in which a larger number of antennas are deployed over a wide area in order to obtain additional spatial dimensions compared to the massive MIMO system is defined as an extra-large scale massive MIMO (XL-MIMO) system. Therefore, methods and apparatuses for managing beams in the XL-MIMO system are required. [Disclosure] [Technical Problem] The present disclosure is directed to providing a method and an apparatus for beam management in a communication system based on XL-MIMO. [Technical Solution] A method of a terminal, according to a first exemplary embodiment of the present disclosure for achieving the above-described objective, may comprise: transmitting, to a base station, a first signal including a terminal beam index for each beam and a first reference signal (RS) by performing beam sweeping of terminal beams; receiving, from the base station, information on scatterer(s) existing on a communication path between the terminal and the base station; receiving, from the base station, information on a number of estimation stages for antenna estimation; performing, with the base station, a first procedure of hierarchically estimating visibility regions (VRs) of antennas of the base station by the number of estimation stages for each scatterer of the scatterer(s); and performing, with the base station, a second procedure of determining base station beams to be used in each of the VRs. The information on the scatterer(s) includes a scatterer identifier and a terminal beam index corresponding to each scatterer. The method may further comprise: transmitting information on a service to be provided to the terminal and VR-related information to the base station after receiving the information on the scatterer(s). The VR-related information may include at least one of information on whether hierarchical VR estimation is supported, or information on a number of beams that the terminal is capable of forming simultaneously. The first procedure may further comprise: receiving, from the base station, an RS transmission instruction through a terminal beam corre