# US 2018/0323849 A1 · Method of transmitting/receiving channel state information reference signal in wireless communication system and device for same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323849 A1 - Document ID: US20180323849A1 - Status: Published application - Kind: A1 - Application number: 15/773,129 - Filed: 2016-11-02 - Published: 2018-11-08 - Earliest claimed: 2015-11-03 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jonghyun PARK; Kijun KIM; Haewook PARK - Web page: https://patentgrep.com/patent/US20180323849A1 ## CPC - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04L 5/0023: {Time-frequency-space} - H04L 5/00: Arrangements affording multiple use of the transmission path - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/14: Two-way operation using the same type of signal, i.e. duplex - H04L 5/1469: {using time-sharing} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04J 11/00: Orthogonal multiplex systems, {e.g. using WALSH codes}(H04J13/00 takes precedence) - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 27/2602: {Signal structure} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) ## Abstract Disclosed herein is a method of receiving a channel state information-reference signal (CSI-RS) of a user equipment (UE) in a wireless communication system, including receiving CSI-RS resource information about a CSI-RS resource location having the CSI-RS mapped thereto, from a base station and receiving the CSI-RS through a CSI-RS resource at a location determined based on the CSI-RS resource information, wherein the CSI-RS resource information includes an index value indicating a location of a CSI-RS resource element where the CSI-RS is transmitted, a period and offset information of a subframe where the CSI-RS is transmitted, and information on a number of antenna ports where the CSI-RS is transmitted, wherein when the index value indicates locations of different CSI-RS resource elements by types of the subframe where the CSI-RS is transmitted and the CSI-RS is set to be transmitted alternately through a normal subframe and a special subframe within one wireless frame, the location of the CSI-RS resource is determined in additional consideration of a type of the subframe in addition to the CSI-RS resource information. ## Claims ### Claim 1 A method of receiving a channel state information-reference signal (CSI-RS) of a user equipment (UE) in a wireless communication system, the method comprising: receiving CSI-RS resource information about a CSI-RS resource location having the CSI-RS mapped thereto, from a base station; and receiving the CSI-RS through a CSI-RS resource at a location determined based on the CSI-RS resource information, wherein the CSI-RS resource information includes an index value indicating a location of a CSI-RS resource element where the CSI-RS is transmitted, a period and offset information of a subframe where the CSI-RS is transmitted, and information on a number of antenna ports where the CSI-RS is transmitted, wherein, when the index value indicates locations of different CSI-RS resource elements by types of the subframe where the CSI-RS is transmitted and the CSI-RS is set to be transmitted alternately through a normal subframe and a special subframe within one wireless frame, the location of the CSI-RS resource is determined in additional consideration of a type of the subframe in addition to the CSI-RS resource information, and wherein a case that the CSI-RS is set to be transmitted alternately through the normal subframe and the special subframe in the one wireless frame is a case that a uplink-downlink configuration is set to 3, 4 or 5, and a transmission period of the CSI-RS is set to 5 ms. ### Claim 2 (canceled) ### Claim 3 (depends on 1) The method of claim 1, wherein, when the subframe where the CSI-RS is transmitted is the normal subframe, the index value indicates a location of a first CSI-RS resource element, and wherein, when the subframe where the CSI-RS is transmitted is the special subframe, the index value indicates a location of a second CSI-RS resource element, wherein the location of the second CSI-RS resource element is defined as a time-shifted form from the location of the first CSI-RS resource element. ### Claim 4 (depends on 3) The method of claim 3, wherein the location of the second CSI-RS resource element is defined as a form time-shifted by a length of 4 OFDM symbols from the location of the first CSI-RS resource element. ### Claim 5 (depends on 1) The method of claim 1, wherein the CSI-RS is transmitted only through a special subframe of a length equal to or greater than a predetermined length. ### Claim 6 (depends on 5) The method of claim 5, wherein the CSI-RS is not transmitted at special subframe configurations 0, 5 and 9. ### Claim 7 (depends on 1) The method of claim 1, wherein the normal subframe or the special subframe where the CSI-RS is transmitted corresponds to a subframe to which a normal cyclic prefix is applied. ### Claim 8 A user equipment (UE) for receiving a channel state information-reference signal (CSI-RS) in a wireless communication system, the user equipment comprising: a radio frequency (RF) unit configured to transmit and receive a wireless signal; and a processor configured to control the RF unit, wherein the user equipment is configured to receive CSI-RS resource information about a CSI-RS resource location having the CSI-RS mapped thereto and receive the CSI-RS through a CSI-RS resource at a location determined based on the CSI-RS resource information, wherein the CSI-RS resource information includes an index value indicating a location of a CSI-RS resource element where the CSI-RS is transmitted, a period and offset information of a subframe where the CSI-RS is transmitted, and information on a number of antenna ports where the CSI-RS is transmitted, wherein, when the index value indicates locations of different CSI-RS resource elements by types of the subframe where the CSI-RS is transmitted and the CSI-RS is set to be transmitted alternately through a normal subframe and a special subframe within one wireless frame, the location of the CSI-RS resource is determined in additional consideration of a type of the subframe in addition to the CSI-RS resource information, and wherein a case that the CSI-RS is set to be transmitted alternately through the normal subframe and the special subframe in the one wireless frame is a case that a uplink-downlink configuration is set to 3, 4 or 5, and a transmission period of the CSI-RS is set to 5 ms. ### Claim 9 (canceled) ### Claim 10 (depends on 8) The user equipment of claim 8, wherein, when the subframe where the CSI-RS is transmitted is the normal subframe, the index value indicates a location of a first CSI-RS resource element, and wherein, when the subframe where the CSI-RS is transmitted is the special subframe, the index value indicates a location of a second CSI-RS resource element, wherein the location of the second CSI-RS resource element is defined as a time-shifted form from the location of the first CSI-RS resource element. ### Claim 11 (depends on 10) The user equipment of claim 10, wherein the location of the second CSI-RS resource element is defined as a form time-shifted by a length of 4 OFDM symbols from the location of the first CSI-RS resource element. ### Claim 12 (depends on 8) The user equipment of claim 8, wherein the CSI-RS is transmitted only through a special subframe of a length equal to or greater than a predetermined length. ### Claim 13 (depends on 12) The user equipment of claim 12, wherein the CSI-RS is not transmitted at special subframe configurations 0, 5 and 9. ### Claim 14 (depends on 8) The user equipment of claim 8, wherein the normal subframe or the special subframe where the CSI-RS is transmitted corresponds to a subframe to which a normal cyclic prefix is applied.