WO2010090485A3 - 무선 이동 통신 시스템에 있어서, 단말기 복조용 참조 신호 전송 방법 및 이를 수행하기 위한 장치 - Google Patents

무선 이동 통신 시스템에 있어서, 단말기 복조용 참조 신호 전송 방법 및 이를 수행하기 위한 장치 Download PDF

Info

Publication number
WO2010090485A3
WO2010090485A3 PCT/KR2010/000759 KR2010000759W WO2010090485A3 WO 2010090485 A3 WO2010090485 A3 WO 2010090485A3 KR 2010000759 W KR2010000759 W KR 2010000759W WO 2010090485 A3 WO2010090485 A3 WO 2010090485A3
Authority
WO
WIPO (PCT)
Prior art keywords
reference signal
demodulation reference
communication system
mobile communication
radio mobile
Prior art date
Application number
PCT/KR2010/000759
Other languages
English (en)
French (fr)
Other versions
WO2010090485A2 (ko
Inventor
정재훈
고현수
한승희
이문일
Original Assignee
엘지전자 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 엘지전자 주식회사 filed Critical 엘지전자 주식회사
Priority to EP10738769.8A priority Critical patent/EP2395721A4/en
Priority to US13/148,063 priority patent/US8982865B2/en
Priority to CN201080007015.0A priority patent/CN102308545B/zh
Publication of WO2010090485A2 publication Critical patent/WO2010090485A2/ko
Publication of WO2010090485A3 publication Critical patent/WO2010090485A3/ko
Priority to US14/617,913 priority patent/US9270432B2/en
Priority to US15/018,429 priority patent/US9490950B2/en
Priority to US15/336,003 priority patent/US9871633B2/en

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/003Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048Allocation of pilot signals, i.e. of signals known to the receiver
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00Baseband systems
    • H04L25/02Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202Channel estimation
    • H04L25/0224Channel estimation using sounding signals
    • H04L25/0226Channel estimation using sounding signals sounding signals per se
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2602Signal structure
    • H04L27/261Details of reference signals
    • H04L27/2613Structure of the reference signals
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/0001Arrangements for dividing the transmission path
    • H04L5/0003Two-dimensional division
    • H04L5/0005Time-frequency
    • H04L5/0007Time-frequency the frequencies being orthogonal, e.g. OFDM(A), DMT
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/0001Arrangements for dividing the transmission path
    • H04L5/0014Three-dimensional division
    • H04L5/0023Time-frequency-space
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/003Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048Allocation of pilot signals, i.e. of signals known to the receiver
    • H04L5/0051Allocation of pilot signals, i.e. of signals known to the receiver of dedicated pilots, i.e. pilots destined for a single user or terminal
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/003Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053Allocation of signaling, i.e. of overhead other than pilot signals
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/0091Signaling for the administration of the divided path
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/04Wireless resource allocation
    • H04W72/044Wireless resource allocation based on the type of the allocated resource
    • H04W72/0446Resources in time domain, e.g. slots or frames
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/20Control channels or signalling for resource management
    • H04W72/23Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J11/00Orthogonal multiplex systems, e.g. using WALSH codes
    • H04J11/0069Cell search, i.e. determining cell identity [cell-ID]
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2602Signal structure
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2602Signal structure
    • H04L27/2603Signal structure ensuring backward compatibility with legacy system
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2602Signal structure
    • H04L27/26035Maintenance of orthogonality, e.g. for signals exchanged between cells or users, or by using covering codes or sequences
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2602Signal structure
    • H04L27/2605Symbol extensions, e.g. Zero Tail, Unique Word [UW]
    • H04L27/2607Cyclic extensions
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/26Systems using multi-frequency codes
    • H04L27/2601Multicarrier modulation systems
    • H04L27/2647Arrangements specific to the receiver only
    • H04L27/2655Synchronisation arrangements
    • H04L27/2662Symbol synchronisation
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/0001Arrangements for dividing the transmission path
    • H04L5/0014Three-dimensional division
    • H04L5/0016Time-frequency-code

Abstract

본 발명은 무선 이동 통신 시스템에 있어서, 데이터 복조용 기준 신호(Demodulation Reference Signal)을 전송하는 방법에 관한 것이다. 상기 방법은 상기 데이터 복조용 기준 신호를 포함하는 서브프레임을 생성하는 단계와 상기 생성된 서브프레임을 전송하는 단계를 포함하고, 복수의 서로 직교하는 복조용 기준 신호 패턴을 포함하는 제1 복조용 기준 신호 패턴 그룹과 제2 복조용 기준 신호 패턴 그룹은 시간-주파수 자원 상에서 서로 구별되고, 랭크가 N인 경우에, 상기 데이터 복조용 기준 신호 중에서 M(M≤N)개 직교하는 복조용 기준 신호 패턴은 제1 복조용 기준 신호 패턴에 포함되고, N-M개의 직교하는 복조용 기준 신호 패턴은 제2 복조용 기준 신호 패턴 그룹에 포함된다.
PCT/KR2010/000759 2009-02-08 2010-02-08 무선 이동 통신 시스템에 있어서, 단말기 복조용 참조 신호 전송 방법 및 이를 수행하기 위한 장치 WO2010090485A2 (ko)

Priority Applications (6)

Application Number Priority Date Filing Date Title
EP10738769.8A EP2395721A4 (en) 2009-02-08 2010-02-08 Method for transmitting reference signal for terminal demodulation in radio mobile communication system, and apparatus for implementing the same
US13/148,063 US8982865B2 (en) 2009-02-08 2010-02-08 Method for transmitting reference signal for terminal demodulation in radio mobile communication system, and apparatus for implementing the same
CN201080007015.0A CN102308545B (zh) 2009-02-08 2010-02-08 在无线移动通信系统中发送终端解调的参考信号的方法以及实现该方法的装置
US14/617,913 US9270432B2 (en) 2009-02-08 2015-02-09 Method for transmitting reference signal for terminal demodulation in radio mobile communication system, and apparatus for implementing the same
US15/018,429 US9490950B2 (en) 2009-02-08 2016-02-08 Method for transmitting reference signal for terminal demodulation in radio mobile communication system, and apparatus for implementing the same
US15/336,003 US9871633B2 (en) 2009-02-08 2016-10-27 Method for transmitting reference signal for terminal demodulation in radio mobile communication system, and apparatus for implementing the same

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US15078409P 2009-02-08 2009-02-08
US61/150,784 2009-02-08
US16305509P 2009-03-25 2009-03-25
US61/163,055 2009-03-25
US16387609P 2009-03-27 2009-03-27
US61/163,876 2009-03-27

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US13/148,063 A-371-Of-International US8982865B2 (en) 2009-02-08 2010-02-08 Method for transmitting reference signal for terminal demodulation in radio mobile communication system, and apparatus for implementing the same
US14/617,913 Continuation US9270432B2 (en) 2009-02-08 2015-02-09 Method for transmitting reference signal for terminal demodulation in radio mobile communication system, and apparatus for implementing the same

Publications (2)

Publication Number Publication Date
WO2010090485A2 WO2010090485A2 (ko) 2010-08-12
WO2010090485A3 true WO2010090485A3 (ko) 2010-11-25

Family

ID=42542530

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2010/000759 WO2010090485A2 (ko) 2009-02-08 2010-02-08 무선 이동 통신 시스템에 있어서, 단말기 복조용 참조 신호 전송 방법 및 이를 수행하기 위한 장치

Country Status (4)

Country Link
US (4) US8982865B2 (ko)
EP (1) EP2395721A4 (ko)
CN (2) CN105141402A (ko)
WO (1) WO2010090485A2 (ko)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102868430B (zh) * 2011-07-05 2017-06-27 中兴通讯股份有限公司 一种开环mimo系统的参考信号处理方法和系统

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102413090B (zh) * 2011-11-04 2014-10-22 电信科学技术研究院 一种传输信息的方法、系统和设备
US9167580B2 (en) * 2012-05-16 2015-10-20 Samsung Electronics Co., Ltd. Method and apparatus for transmission of physical channel in DwPTS
US9660931B2 (en) * 2012-07-25 2017-05-23 Lg Electronics Inc. Method and apparatus for receiving or transmitting radio frequency (RF) signal
KR101731353B1 (ko) 2012-11-04 2017-04-28 엘지전자 주식회사 무선 통신 시스템에서 동기 신호를 송수신하는 방법 및 이를 위한 장치
CN105210342B (zh) * 2013-05-11 2018-10-23 Lg 电子株式会社 考虑载波类型的通信方法及其设备
KR101928879B1 (ko) 2013-06-26 2018-12-13 후아웨이 테크놀러지 컴퍼니 리미티드 참조 신호를 전송하는 방법 및 장치
US9288679B2 (en) * 2013-07-25 2016-03-15 Futurewei Technologies, Inc. System and method for greedy-based autonomous resource block assignment scheme for cellular networks with self-organizing relaying terminals
US10028277B2 (en) * 2013-11-20 2018-07-17 Cyborg Inc. Variable frequency data transmission
JP6376757B2 (ja) * 2014-01-14 2018-08-22 株式会社Nttドコモ ユーザ端末、無線基地局及び無線通信方法
CN107078874B (zh) * 2014-09-24 2020-09-04 Lg 电子株式会社 无线通信系统中发送和接收参考信号的方法及其装置
CN107432006B (zh) * 2015-04-10 2023-05-09 华为技术有限公司 一种信道测量方法、基站及ue
WO2017000228A1 (zh) * 2015-06-30 2017-01-05 华为技术有限公司 一种基于同频组网的载波处理方法及装置
CN106658584B (zh) 2015-10-30 2022-02-15 北京三星通信技术研究有限公司 信号发送与接收和干扰测量的方法及设备
CN107925534A (zh) * 2015-11-06 2018-04-17 华为技术有限公司 一种参考信号的传输方法、用户设备、基站及系统
JP7028646B2 (ja) * 2015-11-27 2022-03-02 株式会社Nttドコモ 端末、無線通信方法、基地局及びシステム
CN107370557B (zh) * 2016-05-13 2021-07-16 中兴通讯股份有限公司 一种信息处理方法、基站、终端和系统
CN107645355A (zh) 2016-07-20 2018-01-30 中兴通讯股份有限公司 控制信道的发送方法和装置、接收方法和装置
WO2018045028A1 (en) * 2016-08-31 2018-03-08 Intel Corporation Csi (channel state information)-rs (reference signal) techniques for channel estimation and beam refinement
US10355803B2 (en) * 2016-10-24 2019-07-16 Qualcomm Incorporated Multiplexing reference signals with scalable numerology for new radio (NR) networks
WO2018182150A1 (ko) * 2017-03-25 2018-10-04 엘지전자(주) 무선 통신 시스템에서 참조 신호를 송수신하기 위한 방법 및 이를 위한 장치
CN112335194B (zh) * 2018-08-10 2023-07-04 株式会社Ntt都科摩 解调参考信号的资源分配方法和基站
KR20210141687A (ko) 2019-03-29 2021-11-23 지티이 코포레이션 기준 시그널링 구성을 위한 시스템 및 방법

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020027952A1 (en) * 2000-09-07 2002-03-07 Yoshiro Kokuryo Method for automatic equalization for use in demodulating a digital multilevel modulation signal and automatic equalization circuit and receiver circuit using the method
US20070274415A9 (en) * 2004-04-16 2007-11-29 Stealth Management, Inc. Single and multiple sinewave modulation and demodulation techniques employing carrier-zero and carrier-peak data-word start and stop
US7336738B2 (en) * 2001-06-15 2008-02-26 Sony Corporation Demodulation timing generation circuit and demodulation apparatus

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3130752B2 (ja) * 1995-02-24 2001-01-31 株式会社東芝 Ofdm伝送受信方式及び送受信装置
EP1832074B1 (en) * 2004-12-27 2013-11-20 Samsung Electronics Co., Ltd. Method and apparatus for transmitting/receiving a signal in an FFH-OFDM communication system
KR100933157B1 (ko) * 2005-05-13 2009-12-21 삼성전자주식회사 직교 주파수 분할 다중 접속 시스템에서 물리채널 색인구성방법 및 장치
JP4892607B2 (ja) * 2006-04-12 2012-03-07 エルジー エレクトロニクス インコーポレイティド MIMOシステムにおいて基準信号割当方法{MethodforallocatingreferencesignalsinMIMOsystem}
KR100785853B1 (ko) 2006-06-05 2007-12-14 한국전자통신연구원 직교 주파수 분할 다중 접속 시스템에서의 자원 할당 방법
KR101307123B1 (ko) * 2007-05-04 2013-09-10 삼성전자주식회사 직교 주파수 분할 다중 접속 시스템에서의 데이터 송수신방법 및 장치
JP5024533B2 (ja) * 2007-06-19 2012-09-12 日本電気株式会社 移動通信システムにおけるリファレンス信号系列の割当方法および装置
US8289946B2 (en) * 2007-08-14 2012-10-16 Qualcomm Incorporated Reference signal generation in a wireless communication system
CN101340228B (zh) * 2008-08-07 2014-05-28 中兴通讯股份有限公司南京分公司 一种参考信号的传输方法
CN101340227B (zh) * 2008-08-15 2012-10-10 中兴通讯股份有限公司 下行参考信号的发送方法和装置
US8644397B2 (en) * 2008-09-23 2014-02-04 Qualcomm Incorporated Efficient multiplexing of reference signal and data in a wireless communication system
US20100195748A1 (en) * 2009-02-02 2010-08-05 Samsung Electronics Co., Ltd. Method and system for reference signal pattern design in resource blocks
US7940740B2 (en) * 2009-02-03 2011-05-10 Motorola Mobility, Inc. Apparatus and method for communicating and processing a positioning reference signal based on identifier associated with a base station
US10009916B2 (en) * 2014-12-23 2018-06-26 Intel Corporation Communication device and method for processing received signals

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020027952A1 (en) * 2000-09-07 2002-03-07 Yoshiro Kokuryo Method for automatic equalization for use in demodulating a digital multilevel modulation signal and automatic equalization circuit and receiver circuit using the method
US7336738B2 (en) * 2001-06-15 2008-02-26 Sony Corporation Demodulation timing generation circuit and demodulation apparatus
US20070274415A9 (en) * 2004-04-16 2007-11-29 Stealth Management, Inc. Single and multiple sinewave modulation and demodulation techniques employing carrier-zero and carrier-peak data-word start and stop

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102868430B (zh) * 2011-07-05 2017-06-27 中兴通讯股份有限公司 一种开环mimo系统的参考信号处理方法和系统

Also Published As

Publication number Publication date
US8982865B2 (en) 2015-03-17
CN102308545A (zh) 2012-01-04
CN102308545B (zh) 2015-06-03
US9490950B2 (en) 2016-11-08
EP2395721A2 (en) 2011-12-14
US20160156446A1 (en) 2016-06-02
US20170048042A1 (en) 2017-02-16
CN105141402A (zh) 2015-12-09
EP2395721A4 (en) 2017-03-01
US9270432B2 (en) 2016-02-23
US20150155987A1 (en) 2015-06-04
WO2010090485A2 (ko) 2010-08-12
US9871633B2 (en) 2018-01-16
US20110286440A1 (en) 2011-11-24

Similar Documents

Publication Publication Date Title
WO2010090485A3 (ko) 무선 이동 통신 시스템에 있어서, 단말기 복조용 참조 신호 전송 방법 및 이를 수행하기 위한 장치
WO2011090353A3 (ko) 다중입출력 무선 통신 시스템에서 하향링크 제어정보를 제공하는 방법 및 장치
WO2009020376A3 (en) Method and apparatus for forming signals in wireless communication systems
WO2011046413A3 (ko) 중계기를 지원하는 무선 통신 시스템에서 다중 사용자 mimo 참조신호를 전송하는 방법 및 장치
WO2010056068A3 (ko) 무선 통신 시스템에서 신호 전송 방법 및 장치
WO2013015613A3 (ko) 무선통신 시스템에서 데이터 전송 방법 및 장치
WO2011014834A3 (en) ROBUST DECODING OF CoMP TRANSMISSIONS
WO2011162522A3 (ko) 채널 상태 정보 전송 방법 및 장치
WO2010016729A3 (en) Method and apparatus for transmitting signal in wireless communication system
WO2010110576A3 (en) Method and apparatus for transmitting reference signal in wireless communication system
WO2010044555A3 (ko) 복수개의 안테나를 이용한 사운딩 기준 신호 시퀀스 전송 방법
WO2010110562A3 (ko) 무선 통신 시스템에서 참조 신호 전송 방법 및 장치
WO2013032202A3 (ko) 하향링크 신호 수신 방법 및 사용자기기와, 하향링크 신호 전송 방법 및 기지국
WO2009110744A3 (ko) 레거시 서포트 모드를 지원하는 레인징 구조, 멀티플렉싱 방법 및 시그널링 방법
JP2011097386A5 (ko)
WO2012008771A3 (ko) 통신 시스템에서의 신호 전송장치 및 방법
WO2010050735A3 (en) 8-transmit antenna reference signal design for downlink communications in a wireless system
WO2011087272A3 (en) A method and an apparatus for providing channel quality information in a wireless communication system
WO2011087313A3 (ko) 무선 통신 시스템에서 제어 정보의 전송 방법 및 장치
WO2011142625A3 (ko) 무선 통신 시스템에서 참조 신호 시퀀스 생성 방법 및 장치
WO2011025208A3 (ko) 부분 주파수 재사용을 이용한 신호 전송 방법
WO2010090415A3 (en) Apparatus and method for transmitting signal in wireless communication system
IN2014KN02668A (ko)
JP2014524217A5 (ko)
WO2011106457A3 (en) Channel state information reference signals

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201080007015.0

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10738769

Country of ref document: EP

Kind code of ref document: A2

WWE Wipo information: entry into national phase

Ref document number: 13148063

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2010738769

Country of ref document: EP