T T A S t a n d a r d

Transcription

1 제정일 : 2017 년 06 월 28 일 T T A S t a n d a r d 5G 시범서비스를위한통신시스템 - 평창올림픽 Communication System for 5G Trial Service - PyeongChang Olympic Games

2 표준초안검토위원회 IMT 프로젝트그룹 (PG906) 표준안심의위원회 전파 / 이동통신기술위원회 (TC9) 성명 소속 직위 위원회및직위 표준번호 표준 ( 과제 ) 제안 이동준 KT 팀장 PG 906 위원 표준초안작성자 김일환 KT 차장 PG 906 위원 사무국담당 김대중 TTA 부장 - 조영익 TTA 책임 - 본문서에대한저작권은 TTA에있으며, TTA와사전협의없이이문서의전체또는일부를상업적목적으로복제또는배포해서는안됩니다. 본표준발간이전에접수된지식재산권확약서정보는본표준의 부록 ( 지식재산권확약서정보 ) 에명시하고있으며, 이후 접수된지식재산권확약서는 TTA 웹사이트에서확인할수있습니다. 본표준과관련하여접수된확약서외의지식재산권이존재할수있습니다. 발행인 : 한국정보통신기술협회회장발행처 : 한국정보통신기술협회 13591, 경기도성남시분당구분당로 47 Tel : , Fax : 발행일 :

3 서 문 1 표준의목적 이표준은평창올림픽 5G 시범서비스를지원하기통신시스템의규격을정의한다. 또한 28GHz 5G 서비스에최적화된무선기술을정의하여향후대한민국 5G 후보주파수인 28GHz 관련산업생태계발전에이바지하는것을목적으로한다. 2 주요내용요약 이표준은평창올림픽 5G 시범서비스를지원하기위한통신시스템무선접속방식및 네트워크구조를정의한다. 이표준은 embb 서비스를위한고속데이터전송및저지연무선 전송기술내용이정의되어있으며, 28GHz 대역동작목적으로설계되어있다. 3 인용표준과의비교 3.1 인용표준과의관련성 - 해당사항없음 3.2 인용표준과본표준의비교표 - 해당사항없음 i

4 Preface 1 Purpose This standard is to define the communication system for 5G Trial Service in PyeongChang 2018 Winter Olympics. 2 Summary This standard defines the communication system for 5G Trial Service in PyeongChang 2018 Winter Olympics. This standard describes wireless and core technology to meet the peak speed and latency requirement which was defined in ITU-R for 5G. Also wireless technology in this standard is optimized in the 28GHz band which will be used for PyeongChang 2018 Winter Olympics 5G trial service. 3 Relationship to Reference Standards - None. ii

5 Contents 1 scope 1 2 Reference 1 3 Definitions 1 4. Abbreviations 2 5 Overall architecture Functional Split Radio Protocol architecture 5 6 Physical Layer for 5G Frame structure Uplink Downlink Generic functions Timing 86 7 Layer MAC Sublayer RLC Sublayer PDCP Sublayer SWI/SPL Sublayer 90 8 RRC Services and Functions RRC protocol states & state transitions Transport of NAS messages System Information Transport of 5G RRC messages 92 iii

6 9 5G Radio identities ARQ and HARQ HARQ principles ARQ principles Mobility Intra E-UTRAN Inter RAT Scheduling and Rate Control Basic Scheduler Operation Measurements to Support Scheduler Operation Rate Control of GBR, MBR and UE-AMBR CSI reporting for Scheduling Explicit Congestion Notification DRX QoS Security Overview and Principles Security termination points G Cell Removal Radio Resource Management aspects UE capabilities S1 Interface X2 Interface 117 iv

7 부록 Ⅰ-1 지식재산권확약서정보 118 Ⅰ-2 시험인증관련사항 119 Ⅰ-3 본표준의연계 (family) 표준 120 Ⅰ-4 참고문헌 121 Ⅰ-5 영문표준해설서 122 Ⅰ-6 표준의이력 125 v

8 5G 시범서비스를위한통신시스템 - 평창올림픽 (Communication System for 5G Trial Service - PyeongChang Olympic Games) 1 Scope The present document provides an overview and overall description of the radio interface protocol architecture for the PyeongChang 5G trial (P5G). 2 References None 3 Definitions 3.1 PLMN ID The PLMN ID used in the LTE network. 3.2 LTE area Tracking areas where only EPS services can be provided. 3.3 LTE UE Normal LTE UE that is not participating the PyeongChang 5G trial. 3.4 Non-P5G cell LTE cell broadcasting the PLMN ID but not the P5G Trial PLMN ID. 3.5 P5G cell LTE cell broadcasting both the PLMN ID and the P5G Trial PLMN ID. 3.6 P5G Trial PLMN ID PLMN ID different from the PLMN ID. 1

9 3.7 P5G UE Enhanced UE that can support the extensions needed to participate the PyeongChang 5G trial. 3.8 P5G area Tracking areas where 5G trial services can be provided. 4 Abbreviations BRS BPSK BRRS CCE CDD CP CQI CRC CSI PCRS CSI DCI DM-RS eplmn 5G Node 5G RA HARQ LTE MAC MBSFN MIMO MCC MNC OFDM P5G PLMN Beam measurement Reference Signal Binary Phase Shift Keying Beam Refinement Reference Signal Control Channel Element Cyclic Delay Diversity Cyclic Prefix Channel Quality Indicator Cyclic Redundancy Check Channel State Information Phase Noise Compensation Reference Signal Channel-State Information Downlink Control Information Demodulation Reference Signal Equivalent PLMN 5G Node 5G Radio Access Hybrid Automatic Repeat Request Long Term Evolution Medium Access Control Multicast/Broadcast over Single Frequency Network Multiple Input Multiple Output Mobile Country Code Mobile Network Code Orthogonal Frequency Division Multiplexing PyeongChang 5G Public Land Mobile Network 2

10 PLMN ID RPLMN xpbch xpdsch xpdcch xprach xpucch xpusch QAM QPP QPSK RLC RRC RSSI RSRP RSRQ SAP TDD TX Diversity UE REG SCG SRS VRB BRS BPSK PLMN Identity (MCC + MNC) Registered PLMN 5G Physical Broadcast Channel 5G Physical Downlink Shared Channel 5G Physical Downlink Control Channel 5G Physical Random Access Channel 5G Physical Uplink Control Channel 5G Physical Uplink Shared Channel Quadrature Amplitude Modulation Quadratic Permutation Polynomial Quadrature Phase Shift Keying Radio Link Control Radio Resource Control Received Signal Strength Indicator Reference Signal Received Power Reference Signal Received Quality Service Access Point Time Division Duplex Transmit Diversity User Equipment Resource-Element Group Secondary Cell Group Sounding Reference Signal Virtual Resource Block Beam measurement Reference Signal Binary Phase Shift Keying 3

11 X2 X2 5 Overall architecture The E-UTRAN for the P5G trial consists of enbs and 5G Nodes, providing the user plane (PDCP/RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE. The enbs are interconnected with each other by means of the X2 interface. The enbs are also connected by means of the S1 interface to the EPC (Evolved Packet Core), more specifically to the MME (Mobility Management Entity) by means of the S1-MME and to the Serving Gateway (S-GW) by means of the S1-U. The 5G Nodes are connected by means of the S1-U interface to the S-GW, but are not connected to the MME via S1-MME. A 5G Node and an enb are interconnected by means of the X2 interface, see clause 19. The interface interconnecting the 5G Nodes is FFS. The corresponding architecture is illustrated on (Figure 5-1) below. MME EPC S-GW S1-MME S1-MME S1-U S1-U S1-U enb X2 5G Node E-UTRAN enb (Figure 5-1) Overall Architecture 5.1 Functional Split The enb, MME, S-GW and PDN Gateway (P-GW) hosts the same functions as in LTE (see 3GPP TS and TS ). The 5G Node hosts the following functions: - Functions for Radio Resource Management: Radio Bearer Control, Radio Admission Control, Connection Mobility Control, Dynamic allocation of resources to UEs in both uplink and downlink (scheduling); 4

12 - Encryption of user data stream; - Routing of User Plane data towards Serving Gateway; - Transmission of system information; - Measurement and measurement reporting configuration for mobility and scheduling. 5.2 Radio Protocol architecture User plane The (figure 5-2) below shows the protocol stack for the user-plane, assuming dual connectivity between LTE and 5G. On the LTE side, the PDCP, RLC and MAC sublayers perform the same functions as in LTE listed in 3GPP TS On the 5G side, the SWI/SPL, PDCP, RLC and MAC sublayers perform the functions listed in subclause 7. SWI/SPL PDCP RLC PDCP RLC PDCP RLC MAC enb MAC 5G Node (Figure 5-2) Radio Protocol Architecture for Dual Connectivity between LTE and 5G Control plane The figure below shows the protocol stack for the control-plane, where: - At the enb, PDCP, RLC and MAC sublayers perform the same functions as listed in 3GPP TS ; - LTE RRC (terminated in enb on the network side) performs the same functions as listed in 3GPP TS ; - 5G RRC signalling always uses LTE radio resources to be transmitted and uses a specific DRB for that purpose; - 5G RRC performs the functions listed in subclause 8, e.g.: 5G RRC connection management; 5G mobility; 5

13 5G security control. RRC SRB PDCP RLC DRB PDCP RLC 5G RRC MAC enb 5G Node (Figure 5-3) Control-plane protocol stack 6 Physical Layer for 5G 6.1 Frame structure Throughout this specification, unless otherwise noted, the size of various fields in the time domain is expressed as a number of time units Ts = 1 ( ) seconds. T ms Each radio frame is f = T s = long and consists of 100 slots of length Tslot = Ts = 0.1ms, numbered from 0 to 99. A subframe is defined as two consecutive slots where subframe i consists of slots 2i and Subframes can be dynamically used for downlink and uplink transmission with exception of control subframes used for synchronization, cell and beam search, and random access. The first OFDM symbol in all other subframes is reserved for downlink transmission. A UE treats all OFDM symbols in a subframe as downlink except for OFDM symbols where it has been explicitly instructed to transmit in the uplink. A UE is not expected to receive in the downlink during the OFDM symbol prior to an uplink transmission which forms a guard period for UL-DL switch and timing advance. A UE is not expected to receive in the downlink in any OFDM symbol where it is scheduled for uplink transmission on at least one component carrier. i. 6

14 One radio frame, Tf = Ts = 10 ms One slot, Tslot=15360Ts Subframe #0 Subframe #1 Subframe #2 Subframe #3 Subframe #4 Subframe #5 Subframe #47 Subframe #48 Subframe #49 One subframe, 30720Ts (Figure 6-1) Frame structure The supported subframe configurations are listed in <Table 6-1>. Subframes denoted by broadcast subframe index are used for the transmission of xpbch, PSS, SSS, ESS, and BRS. Subframes denoted by index of KRACH and KePBCH are respectively used for the transmission of RACH and epbch. Subframes indicated as data subframe are comprised a. DL control channel and DL data channel, or b. DL control channel, DL data channel and UL control channel, or c. DL control channel and UL data channel, or d. DL control channel, UL data channel and UL control channel. The supported data subframe configurations are listed in <Table 6-2>, where for each symbol in a subframe, Dc denotes a downlink symbol reserved for downlink control channel transmissions, Dd denotes a downlink symbols reserved for downlink data channel transmissions and, Uc denotes a uplink symbol reserved for uplink control channel transmissions, Ud denotes a uplink symbols reserved for uplink data channel transmissions, and GP denotes a symbol reserved for guard period between downlink and uplink transmissions. CSI-RS and BRRS are respectively denoted by C.RS and B.RS. <Table 6-1> Subframe configurations Control subframes Data subframes PSS/SSS/ESS/BRS/xPBCH, RACH, epbch (*) Configurations in <Table 6-2> (*) Systems supporting stand-alone operations have epbch subframes. 7

15 Configu -rations <Table 6-2> Example configurations for data subframe structure Symbol index Dd Dd 0 Dc Dd Dd Dd Dd Dd Dd Dd Dd Dd Dd Dd C.RS C.RS Uc 1 Dc Dd Dd Dd Dd Dd Dd Dd Dd Dd Dd Dd GP SRS Dd Dd 2 Dc Dc Dd Dd Dd Dd Dd Dd Dd Dd Dd Dd C.RS C.RS Uc 3 Dc Dc Dd Dd Dd Dd Dd Dd Dd Dd Dd Dd GP SRS 4 Dc GP Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud 5 Dc GP Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud Uc SRS 6 Dc GP Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud C.RS 7 Dc GP Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud SRS C.RS 8 Dc GP Ud Ud Ud Ud Ud Ud Ud Ud Ud Ud SRS Uc 9 Dc -/Dc B.RS B.RS B.RS B.RS B.RS B.RS B.RS B.RS B.RS B.RS GP 10 Dc - /Dc B.R S B.R S B.R S B.R S B.R S B.R S B.R S B.R S B.R S B.R S C.R S Uc SRS C.R S 6.2 Uplink Overview The smallest resource unit for uplink transmissions is denoted a resource element and is defined in clause Physical channels The following uplink physical channels are defined: - Physical Uplink Shared Channel, xpusch - Physical Uplink Control Channel, xpucch - Physical Random Access Channel, xprach Physical signals An uplink physical signal is used by the physical layer but does not carry information originating from higher layers. The following uplink physical signals are defined: - Reference signal 8

16 6.2.2 Slot structure and physical resources Resource grid The transmitted signal in each slot is described by one or several resource grids of UL RB N RB Nsc = 1200 subcarriers and illustrated in (Figure 6-2). UL N symb = 7 OFDM symbols. The resource grid is An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. There is one resource grid per antenna port. The antenna ports used for transmission of a physical channel or signal depends on the number of antenna ports configured for the physical channel or signal as shown in <Table 6-3>. The index p~ is used throughout clause 5 when a sequential numbering of the antenna ports is necessary. One uplink slot Tslot UL Nsymb OFDM symbols UL RB RB sc k = N N 1 Resource block N N resource elements UL symb RB sc N subcarriers RB sc UL RB N N sc subcarriers RB Resource element ( k, l) k = 0 UL l = 0 l = N symb 1 (Figure 6-2) Uplink resource grid 9

17 <Table 6-3> Antenna ports used for different physical channels and signals Antenna port number p as a function of Physical channel or signal Index p~ the number of antenna ports configured for the respective physical channel/signal xpusch SRS xpucch PCRS Up to two antenna ports per UE are supported for the PyeongChang trial system Resource elements Each element in the resource grid is called a resource element and is uniquely defined by the index pair ( l) k, UL RB in a slot where k = 0,..., NRB Nsc 1 and UL l = 0,..., N symb 1 are the indices in the frequency and time domains, respectively. Resource element ( k, l) on antenna port p corresponds to the complex value ( p) a k, l. When there is no risk for confusion, or no particular antenna port is specified, the index p may be dropped. Quantities ( p) a k, l corresponding to resource elements not used for transmission of a physical channel or a physical signal in a slot shall be set to zero. 10

18 Resource blocks A physical resource block is defined as UL N symb consecutive OFDM symbols in the time domain and N RB sc consecutive subcarriers in the frequency domain, where UL N symb and RB N sc are given by <Table 6-4>. A physical resource block in the uplink thus consists of UL symb N N RB sc resource elements, corresponding to one slot in the time domain and 900 khz in the frequency domain. <Table 6-4> Resource block parameters Configuration RB N sc UL N symb Cyclic prefix 12 7 The relation between the physical resource block number n PRB in the frequency domain and resource elements ( k, l) in a slot is given by n PRB k = N RB sc Virtual resource block groups of localized type UL Virtual resource block groups of localized type are numbered from 0 to N VRBG 1, where 4N = N UL VRBG UL RB. Virtual resource block group of index UL n VRBG of physical resource block pairs given by { 4 UL, 4 UL 1, 4 UL 2, 4 UL n 3} VRBG nvrbg + nvrbg + nvrbg + is mapped to a set Physical uplink shared channel (xpusch) The baseband signal representing the physical uplink shared channel is defined in terms of the following steps: - scrambling - modulation of scrambled bits to generate complex-valued symbols - mapping of the complex-valued modulation symbols onto one or several transmission layers - precoding of the complex-valued symbols - mapping of precoded complex-valued symbols to resource elements 11

19 - generation of complex-valued time-domain OFDM signal for each antenna port - analog beamforming based on the selected beam codewords layers antenna ports Scrambling Scrambling Modulation mapper Modulation mapper Layer mapper Precoding Resource element mapper Resource element mapper OFDM signal generation OFDM signal generation Analogue beamforming Analogue beamforming <Figure 6-3> Overview of uplink physical channel processing Scrambling For a codeword q, the block of bits b (0),..., b ( M bit 1), where ( q) ( q) ( q) ( q) bit M is the number of bits transmitted in codeword q on the physical uplink shared channel in one subframe, shall be scrambled with a UE-specific scrambling sequence prior to modulation, resulting in a block of scrambled bits following pseudo code Set i = 0 ~ (0),..., b ~ ( q) ( q) (q) b ( M bit 1) according to the while i < M ( q) bit if ( ) b q ( i) = x ~ b q ) ( ( i) = 1 // ACK/NACK or Rank Indication placeholder bits else if ~ ( q) ) b else ( ) b q ( i) = y ~ ( q ( i) = b ( i 1) // ACK/NACK or Rank Indication repetition placeholder bits // Data or channel quality coded bits, Rank Indication coded bits or ACK/NACK coded bits ( i) = ( q) ( q ( b ( i) + c ( i) ) mod 2 ~ ( q) ) b end if end if i = i + 1 end while 12

20 The scrambling sequence generator shall be initialised with init = nrnti + q 2 + ns 2 2 c 2 + N cell ID at the start of each subframe. Only one codewords can be transmitted in one subframe, i.e., q = Modulation For an codeword q, the block of scrambled bits ~ ( q) ~ ( q) (q) b (0),..., b ( M bit 1) shall be modulated as described in clause 6.4.1, resulting in a block of complex-valued symbols d ( q) (0),..., d ( q) ( M ( q) symb 1). <Table 6-5> specifies the modulation mappings applicable for the physical uplink shared channel. <Table 6-5> Uplink modulation schemes Physical channel Modulation schemes PUSCH QPSK, 16QAM, 64QAM Layer mapping The complex-valued modulation symbols for the codeword to be transmitted are mapped onto one or two layers. Complex-valued modulation symbols d ( q) (0),..., d ( q) ( M ( q) symb 1) for codeword q shall be mapped onto the layers ( 0) ( υ 1) [ x ( i)... x ( i ] T x ( i) = ), layer i = 0,1,..., M symb 1 where υ is the number of layers and layer M symb is the number of modulation symbols per layer Layer mapping for transmission on a single antenna port For transmission on a single antenna port, a single layer is used, υ = 1 mapping is defined by (0) x ( i) = d (0) ( i), and the with layer symb M = M (0) symb. 13

21 Layer mapping for spatial multiplexing For spatial multiplexing, the layer mapping shall be done according to <Table 6-6>. The number of layers υ is one or two. <Table 6-6> Codeword-to-layer mapping for spatial multiplexing Number of layers Number of codewords Codeword-to-layer mapping i = layer 0,1,..., M symb 1 (0) (0) 1 1 x ( i) = d ( i) 2 1 x x (0) (1) ( i) = d ( i) = d (0) (0) (2i) (2i + 1) layer symb M = M layer symb M = M (0) symb (0) symb Layer mapping for transmit diversity For transmit diversity, the layer mapping shall be done according to <Table 6-7>. There is only one codeword and the number of layers υ is two. <Table 6-7> Codeword-to-layer mapping for transmit diversity Number of layers Number of codewords Codeword-to-layer mapping i = layer 0,1,..., M symb x x (0) (1) ( i) = d ( i) = d (0) (0) (2i) (2i + 1) layer symb M = M (0) symb Precoding The precoder takes as input a block of vectors (0) ( υ 1) x i x i i = 0,1,..., M 1, symb ( )... ( ) T layer ( 0) ( P 1) [ z ( i) z ( i) from the layer mapping and generates a block of vectors ]T, ap i = 0,1,..., M symb 1 to be mapped onto resource elements Precoding for transmission on a single antenna port For transmission on a single antenna port, p, indicated in the uplink resource allocation, DCI format A1, precoding is defined by 14

22 () () ( p) (0) z i = x i where, ap i = 0,1,..., M symb 1, ap symb M = M layer symb Precoding for transmit diversity Precoding for transmit diversity is only used in combination with layer mapping for transmit diversity as described in clause The precoding operation for transmit diversity is defined for two antenna ports. For transmission on two antenna ports, p 1 and p 2, indicated in the uplink resource ( p [ ] T 1) ( p2 ) z ( i) = z ( i) z ( i) allocation, DCI format A1, the output precoding operation is defined by ( z ( z ( p1 z ( p2 z ) 1) (2i) 1 2 ) (2i) 1 = 0 (2i + 1) (2i 1) 1 p p ) 0 j j, (0) ( x ( i) ) (1) ( x ( i) ) (0) ( x ( i) ) 0 Re j Re j Im 0 ( ) (1) Im x ( i) ap i = 0,1,..., M symb 1 of the layer 0,1,..., 1 for i = M symb with ap symb M = 2M layer symb. DM-RS 0 DM-RS 1 Precoding W v layers P antenna ports (Figure6-4) DM-RS location for transmit diversity For transmit diversity, DM-RS is located after precoding with P = 2 antenna ports as illustrated in (Figure 6-4) Precoding for spatial multiplexing Precoding for spatial multiplexing is only used in combination with layer mapping for spatial multiplexing as described in clause 5.3.2A.2. Spatial multiplexing supports 15

23 = 2 P antenna ports where the set of antenna ports used for spatial multiplexing are p1 and p 2, indicated in the uplink resource allocation, DCI format A1. Precoding for spatial multiplexing is defined by z z ( p ) 1 ( p 2 ) ( i) ( i) y = W ( y υ ( i) 1) ( i) (0) where ap i = 0,1,..., M symb 1, ap symb M = M layer symb. For transmission on two antenna ports, p1 and p2 the precoding matrix W (i) shall be generated according to from <Table 6-8>. <Table 6-8> Codebook for transmission on antenna ports { p 1, p 2 } Codebook index Number of layers υ j j DM-RS 0 DM-RS 1 Precoding W v layers P antenna ports (Figure 6-5) DM-RS location for spatial multiplexing using antenna ports with UE-specific reference signals 16

24 For spatial multiplexing using antenna ports with UE-specific reference signals, DM- RS is located before precoding with υ layers as illustrated in (Figure 6-5) Mapping to physical resources For each antenna port p block of complex-valued symbols amplitude scaling factor used for transmission of the xpusch in a subframe the β xpusch z ( ~ p) (0),..., z ( ~ p) ( M ap symb 1) shall be multiplied with the P in order to conform to the transmit power xpusch, ( ~ p) and mapped in sequence starting with z (0) to physical resource blocks on antenna port p ( k,l) and assigned for transmission of xpusch. The mapping to resource elements corresponding to the physical resource blocks assigned for transmission and - not used for transmission of phase noise compensation reference signal, andnot part of OFDM symbol(s) including DM-RS in a subframe, and - not part of the first two OFDM symbols in a subframe, and - not part of the last OFDM symbol(s) in a subframe if indicated in the scheduling DCI shall be in increasing order of first the index k, then the index l, starting with the first slot in the subframe Physical uplink control channel (xpucch) The physical uplink control channel, xpucch, carries uplink control information. The xpucch can be transmitted in the last symbol of a subframe. cell xpucch uses a cyclic shift, n cs ( n s ), which varies with the slot number n s according to n cell 7 UL i cs ( ns) = = c(8n + 0 symb n ) 2 i s i n s = n s mod20 where the pseudo-random sequence c(i) is defined by section 7.2. The pseudorandom sequence generator shall be initialized with RS c init = n ID where RS n ID is given by Section The physical uplink control channel supports single format as shown in <Table 6-9>. 17

25 <Table 6-9>Supported xpucch formats xpucch format Modulation scheme Number of bits per subframe, M bit 2 QPSK xpucch formats 2 The block of bits b(0),..., bm ( bit 1) shall be scrambled with a UE-specific scrambling sequence, resulting in a block of scrambled bits ( ) bi () = bi () + ci () mod2 b (0),..., bm ( 1) bit according to where the scrambling sequence c(i) is given by clause 7.2. The scrambling sequence generator shall be initialized with ( s ) ( ) c = n N n cell 16 init ID RNTI n s = n s mod 20 at the start of each subframe where The block of scrambled bits nrnti b (0),..., bm ( 1) bit is the C-RNTI. shall be QPSK modulated as described in sub-clause 7.1, resulting in a block of complex-valued modulation symbols d(0),..., dm ( symb 1) Msymb = Mbit 2 where Layer mapping The complex-valued modulation symbols to be transmitted are mapped onto one or two layers. Complex-valued modulation symbols d ( 0),..., d ( M symb 1) shall be mapped ( 0) ( υ 1) x ( i) = [ x ( i)... x ( i) ] T on to the layers, layer i = 0,1,..., M symb 1 where υ is the number of layers and layer M symb is the number of modulation symbols per layer. For transmission on a single antenna port, a single layer is used, υ = 1, and the mapping is defined by with M = M layer symb (0) symb. (0) x ( i) = d( i) For transmission on two antenna ports, and the mapping rule of υ = 2 can be defined 18

26 by x x (0) (1) ( i) = d(2i) ( i) = d(2i + 1) with M = M layer symb (0) symb / Precoding (0) ( υ 1) x ( i)... x ( i) T The precoder takes as input a block of vectors i = layer 0,1,..., M 1, symb ( 0) ( P 1) from the layer mapping and generates a block of vectors [ y ( i) y ( i) ] T, ap i = 0,1,..., M symb 1 to be mapped onto resource elements. For transmission on a single antenna port, precoding is defined by (0) y ( i) = x (0) ( i) where ap i = 0,1,..., M symb 1 and ap symb M = M layer symb. ~ For transmission on two antenna ports, { 0,1} (0) (1) p y ( i) = [ y ( i) y ( i) ] T, the output, ap i = 0,1,..., M symb 1 of the precoding operation is defined by (0) y (2i) 1 (1) y (2i) 1 = 0 (0) y (2i + 1) 2 0 (1) y (2i + 1) 1 0 j j (0) ( x ( i) ) (1) ( x ( i) ) (0) ( x ( i) ) 0 Re j Re j Im 0 ( ) (1) Im x ( i) for layer i = 0,1,..., M symb 1 with ap symb M = 2M layer symb. The mapping to resource elements is defined by operations on quadruplets of complex-valued symbols. Let symbol quadruplet i for antenna port p, where The block of quadruplets ( p ) ( p ) w w Mquad (0),..., ( 1) ( p ) ( p ) ( p ) ( p ) ( p ) w i y i y i y i y i ( p ) ( p ) w w Mquad where ( ) = (4 ), (4 + 1), (4 + 2), (4 + 3) (0),..., ( 1) ( p ) ( p ) ( p ) ( p ) ( p ) w i y i y i y i y i ( ) = (4 ), (4 + 1), (4 + 2), (4 + 3) antenna port p i = 0,1,..., M quad 1 and M quad = M symb denote shall be cyclically shifted, resulting in p ( ) = (( + cs ( s )) mod quad ) ( p w ) i w ( ) i n cell n M obtained after cell-specific cyclic shift. 4. Let denote another symbol quadruplet i for The block of complex-valued symbols w shall be mapped to z according to 19

27 p ( xpucch xpucch sc + ' sc + ') = ( 8 ' + ) ( p z ) n (2) N RB N RB m N RB k y ( ) m k where and (2) n xpucch k 0 k 1 k' = k+ 2 2 k 5 k k 7 m' = 0,1, 2,,5 N = 6 RB xpucch is indicated in the xpdcch Reference signals Four types of uplink reference signals are supported: - Demodulation reference signal, associated with transmission of xpucch - Demodulation reference signal, associated with transmission of xpusch - Phase noise compensation reference signal, associated with transmission of xpusch (PCRS) - Sounding reference signal, not associated with transmission of xpusch or xpucch Generation of the reference signal sequence Reference signal sequence u, ( n) according to r v ( α ) r u v, ( n) is defined by a cyclic shift α of a base sequence ( α ) j n u, v n) = e α ru, v ( n), 0 n < r ( M RS sc where RS RB M sc = mnsc is the length of the reference signal sequence and 1 m N RB max, UL. Multiple reference signal sequences are defined from a single base sequence through different values of α. Base sequences u ( ) are divided into groups, where u { 0,1,...,29} r, v n is the group number and v is the base sequence number within the group, such that each group RS RB contains one base sequence ( v = 0 ) of each length M sc = mnsc, 2 m 5 and two base sequences ( v = 0, 1) of each length RS sc RB sc M = mn, 6 m N RB max,ul. The sequence 20

28 group number u and the number v within the group may vary in time as described in clauses and , respectively. The definition of the base sequence r (0),..., r ( M 1) RS uv, uv, sc depends on the sequence length M RS sc Base sequences of length larger than RB 3N sc RS RB For M sc 3Nsc, the base sequence RS ru, v (0),..., ru, v ( M sc 1) is given by where the th q RS u, v n) = xq ( n mod N ZC ), 0 n < r ( M root Zadoff-Chu sequence is defined by RS sc with q given by x q πqm( m+ 1) j RS N RS ( m) = e ZC, 0 m N 1 2q q = q v ( 1) q = N RS ZC ( u + 1) 31 ZC The length N ZC RS of the Zadoff-Chu sequence is given by the largest prime number such that RS ZC RS sc N < M Base sequences of length less than RB 3N sc For RS sc RB sc M = 2N, base sequence is given by jϕ ( n) π 4 RS ru, v ( n) = e, 0 n M sc 1 where the value of ϕ(n) is given by <Table 6-10> for RS sc RB sc M = 2N, respectively. 21

29 u ϕ( 0),..., ϕ(23) <Table 6-10> Definition of ϕ(n) for RS sc M = 2N RB sc

30 Group hopping The sequence-group number u in slot n s is defined by a group hopping pattern f gh ( n s ) and a sequence-shift pattern f ss according to ( f n ) f ) mod 30 u = + gh ( s ss There are 17 different hopping patterns and 30 different sequence-shift patterns. Sequence-group hopping can be enabled or disabled by means of the cell-specific parameter Group-hopping-enabled provided by higher layers. The group-hopping pattern f gh ( n s ) for SRS is given by f = 0 if group hopping isdisabled ns) mod30 if group hopping is enabled = gh( 7 i ( c(8n + ) 2 ) i 0 s i n s = n s mod20 where the pseudo-random sequence c(i) is defined by clause 7.2. The pseudorandom sequence generator shall be initialized with c init RS n ID = 30 at the beginning of each radio frame where RS n ID is given by clause The sequence-shift pattern f ss definition differs between xpucch and SRS. For xpucch, the sequence-shift pattern PUCCH ss PUCCH f is given by f ss = nid mod30 where RS RS n ID is given by clause For SRS, the sequence-shift pattern given by clause SRS ss SRS f is given by f ss = nid mod30 where RS RS n ID is Sequence hopping Sequence hopping only applies for reference-signals of length RS sc RB sc M 6N. For reference-signals of length RS sc base sequence group is given by v = 0. RB sc M < 6N, the base sequence number v within the For reference-signals of length RS sc RB sc M 6N, the base sequence number v within the base sequence group in slot ns is defined by 23

31 c( n mod20) v = s 0 if group hopping isdisabled and sequence hopping isenabled otherwise where the pseudo-random sequence c(i) is given by clause 7.2. The parameter Sequence-hopping-enabled provided by higher layers determines if sequence hopping is enabled or not. For SRS, the pseudo-random sequence generator shall be initialized with c init RS nid = n RS ( + ) mod30 ID ss at the beginning of each radio frame where n ID RS is given by clause and ss is given by clause Determining virtual cell identity for sequence generation The definition of RS n ID depends on the type of transmission. Transmissions associated with xpucch: - - RS ID cell ID n = N if no value for RS ID PUCCH ID n = n otherwise. xpucch n ID is configured by higher layers, Sounding reference signals: - n RS ID cell = NID if no value for xsrs n ID is configured by higher layers, n = n RS ID xsrs ID otherwise Demodulation reference signals associated with xpucch Demodulation reference signals associated with xpucch are transmitted on single antenna port p = 100 or two antenna ports p = 200, p = Sequence generation For any of the antenna ports p { 100,200,201} the reference signal sequence r l n s, ( m) is defined by 1 1 ( m) = N 2 2 UL ( 1 2 c(2m) ) + j ( 1 2 c(2m + 1) ), m = 0,1,...,4 1 r l, ns RB where ns is the slot number within a radio frame and l is the OFDM symbol number 24

32 within the slot. The pseudo-random sequence c(i) is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with c ( nscid ) 16 ( ns / 2 + 1) ( 2n + 1) + nrnti init = ID 2 n s = n s mod20 at the start of each subframe where n RNTI is the C-RNTI. The quantities ( i) ID n, i = 0, 1, are given by - - ( ) ID cell ID n i = N if no value for ( i) xpucch, i nid = nid otherwise n xpucch,i ID is provided by higher layers. n The value of SCID is zero unless specified otherwise. For an xpucch transmission, n SCID is given by the DCI formats in associated with the xpucch transmission Mapping to resource elements In a physical resource block with frequency-domain index n PRB assigned for the corresponding xpucch transmission, a part of the reference signal sequence r(m) shall be mapped to complex-valued modulation symbols according to a m mod 2) r (4 n ( p) k, l = wp ( l, ns PRB + m ) ( p) a k, l in a subframe where s w wp ( i) = w k = N p p RB sc ( i) (1 i) n PRB PRB PRB + m l = 6 m m 1 m' = m m 3 m = 0,1,2,3 n mod 2 = 1 n n mod 2 = 0 mod 2 = 1 and the sequence w p (i) is given by <Table 6-11>. 25

33 <Table 6-11> The sequence w p (i) Antenna port p [ w p ( 0) wp (1) ] 100 or 200 [ +1 +1] 201 [ +1 1] R100 R100 R100 R100 l = 0 l = 6 l = 0 l = 6 even-numbered slots odd-numbered slots Antenna port 100 R200 R201 R200 R201 R200 R201 R200 R201 l = 0 l = 6 l = 0 l = 6 even-numbered slots odd-numbered slots Antenna port 200 l = 0 l = 6 l = 0 l = 6 even-numbered slots odd-numbered slots Antenna port 201 (Figure 6-6) Mapping of xpucch demodulation reference signals (Figure 6-6) illustrates the resource elements used for xpucch demodulation reference signals according to the above definition. The notation R p is used to denote a resource elements used for reference signal transmission on antenna port p Demodulation reference signals associate with xpusch UE specific reference signals associated with xpusch 26

34 - are transmitted on antenna port(s) p = 40,41,42,43 ; - are present and are a valid reference for xpusch demodulation only if the xpusch transmission is associated with the corresponding antenna port; - are transmitted only on the physical resource blocks upon which the corresponding xpusch is mapped. A UE-specific reference signal associated with xpusch is not transmitted in resource elements ( k, l) in which one of the physical channels are transmitted using resource elements with the same index pair ( k, l) regardless of their antenna port p Sequence generation For any of the antenna ports p { 40,41,42,43} the reference-signal sequence ( m) defined by r 1 1 max, N RB 2 2 DL ( m) = ( 1 2 c( 2m) ) + j ( 1 2 c( 2m + 1) ), m = 0,1,...,3 1. r is The pseudo-random sequence c(i) is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with at the start of each subframe. ( i) The quantities n ID, i = 0, 1, are given by c ( nscid ) 16 ( ns / 2 + 1) ( 2n + 1) + nscid init = ID ( ) ID cell ID n i = N if no value for n ( i) n DMRS, i ID ID = otherwise n DMRS,i ID is provided by higher layers The value of n SCID is zero unless specified otherwise. For a xpusch transmission, n SCID is given by the DCI format associated with the xpusch transmission Mapping to resource elements For antenna ports p { 40,41,42,43}, in a physical resource block with frequencydomain index n PR B assigned for the corresponding xpusch transmission, a part of 27

35 the reference signal sequence r(m) shall be mapped to complex-valued modulation symbols where ( p) a k, l in a subframe according to k = 0 1 k' = 2 3 m' + N RB 4 sc nprb p p p p { 40} { 41} { 42} { 43} ( ) r( ') a p k l = + k', k' k k' ' = 4 2 (in even slot) l = 2 (in even slot), 3(in odd slot) m' = 0,1,2 for high speed case Information indicating whether l = 2 or l = { 2,10} l=2, 10 is signaled via higher layer signaling. Resource elements ( k, l) used for transmission of UE-specific reference signals to one UE on any of the antenna ports in the set S, where, S = { 40}, S = { 41}, S = { 42} or = { 43} S shall - not be used for transmission of xpusch on any antenna port in the same subframe, and - not be used for UE-specific reference signals to the same UE on any antenna port other than those in S in the same subframe. (Figure 6-7) illustrates the resource elements used for UE-specific reference signals for antenna ports 40, 41, 42 and

36 (Figure 6-7) Mapping of UE-specific reference signals, antenna ports {40, 41,42,43} Sounding reference signal Sounding reference signals are transmitted on antenna port(s), { 40,41} p Sequence generation ( ~ p The sounding reference signal sequence r ) ( α ~ p ) ( n) = r ( n) SRS u, v is defined by clause 5.5.1, where u is the sequence-group number defined in clause and ν is the p base sequence number defined in clause The cyclic shift α ~ of the sounding reference signal is given as 29

37 where n cs { 0,1, 2,3, 4,5,6,7} SRS ~ cs,p nsrs α ~ p = 2π 8 8 ~ ~ cs,p cs p n mod8 SRS = nsrs + N ap ~ p { 0,1,..., N 1} ap, is configured for aperiodic sounding by the higher-layer parameters cyclicshift-ap for each UE and for sounding reference signal transmission. Nap is the number of antenna ports used Mapping to physical resources The sequence shall be multiplied with the amplitude scaling factor β SRS conform to the transmit power P SRS in order to, and mapped in sequence starting with r SRS(0) to ( ~ p) resource elements ( k, l) on antenna port p according to a ( p) 2k ' + k0, l = N 0 1 ( ~ p β ) ( ') ' = 0,1,, RS SRSrSRS k k M sc, b ap otherwise 1 where Nap is the number of antenna ports used for sounding reference signal transmission and the relation between the index p~ and the antenna port p is given k by <Table 6-12>. The quantity 0 is the frequency-domain starting position of the sounding reference signal, b = BSRS and RS M sc,b is the length of the sounding reference signal sequence defined as M RS = sc, b m SRS, b N RB sc 2 where m SRS, b is given by <Table 6-12>. The UE-specific parameter srs-bandwidth, B SRS {0,1,2,3} is given by higher layers. k The frequency-domain starting position 0 is defined by k 0 = k TC + n b N RB sc where k TC {0,1 } is given by the UE-specific parameter transmissioncomb-ap, provided by higher layers for the UE, and nb is frequency position index. The frequency position index n b remains constant (unless re-configured) and is 30

38 defined by nb = 4nRRC where the parameter n RRC is given by higher-layer parameters freqdomainposition-ap, SRS can be transmitted simultaneously in multiple component carriers. m <Table 6-12> SRS, b, b = 0,1,2, 3, values for the uplink bandwidth of UL N RB = 100 SRS bandwidth configuration C SRS SRS- Bandwidth B SRS = 0 SRS- Bandwidth B SRS = 1 SRS- Bandwidth B SRS = 2 SRS- Bandwidth B SRS = 3 msrs,0 msrs, 1 msrs, 2 m SRS, Sounding reference signal subframe configuration The sounding reference signal is always aperiodic and explicitly scheduled via PDCCH. The subframe number and symbol number (last symbol or the second last symbol) of SRS are conveyed in DCI Phase noise compensation reference signal, associated with transmission of PUSCH Phase noise compensation reference signal associated with xpusch - are transmitted on one antenna port assigned to UE; - are transmitted only on the physical resource blocks upon which the corresponding xpusch is mapped Sequence generation For any of the antenna ports p { 40,41,42,43}, the reference-signal sequence ( m) defined by r 1 1 UL ( m) = ( 1 2 c( 2m) ) + j ( 1 2 c( 2m + 1) ), m = 0,1,..., N symb. r is The pseudo-random sequence c(i) is defined in clause 7.2. The pseudo-random 31

39 sequence generator shall be initialised with at the start of each subframe. The quantities c = ( nscid ) 16 ( ns / 2 + 1) ( 2nID + 1) + nscid init 2 ( i) n ID, i = 0, 1, are given by n s = n s mod ( ) ID cell ID n i = N if no value for n ( i) n DMRS, i ID ID = otherwise n DMRS,i ID is provided by higher layers The value of n SCID is zero unless specified otherwise. For a xpusch transmission, n SCID is given by the DCI format in associated with the xpusch transmission Mapping to resource elements For antenna ports p { 40,41,42,43}, in a physical resource block with frequencydomain index n PRB ' assigned for the corresponding xpusch transmission, a part of the reference signal sequence r(m) shall be mapped to complex-valued modulation symbols ( p) a k, l in a subframe according to ( ) r( ) a p k l =, l' where l ' is the symbol index within a subframe, the starting resource block number of xpusch physical resource allocation n xpusch PRB in the frequency domain, resource allocation bandwidth in terms of number of resource blocks xpusch N PRB and resource elements ( k, l' ) in a subframe is given by xpusch RB xpusch N PRB ' k = N sc nprb k 4 20 p 40 ' 21 p 41 k = 22 p p 43 3,...,13, if Subframe configuration = 4 l = 3,...,12, if Subframe configuration = 5 or 6 3,...,11, if Subframe configuration = 7 or 8 32

40 Resource elements ( k, l) used for transmission of UE-specific phase noise compensation reference signals from one UE on an antenna port S = { 40}, S = { 41}, S = { 42} or = { 43} S shall p S, where - not be used for transmission of xpusch on any antenna port in the same subframe. (Figure 6-8) illustrates the resource elements used for phase noise compensation reference signals for antenna ports 40, 41, 42 and 43. xpusch n PRB xpusch N PRB xpdcch Symbol GP DMRS Symbol 4PRB 1 subframe UL control Symbol (Figure 6-8) Mapping of phase noise compensation reference signals, antenna ports 50, 51, 52 and 53 33

41 6.2.6 OFDM baseband signal generation This clause applies to all uplink physical signals and uplink physical channels. The time-continuous signal slot is defined by s ( p) l ( t) 0 t < N l + N T ( ) for CP, s ( s p ) l ( t) on antenna port p UL RB 1 N RB Nsc / 2 ( p) j2πk f ( t NCP, lts ) ( p) = a ( ) e + a ( + ) k, l k UL RB k= N RB Nsc / 2 k= 1 ( ) UL RB where k = k + N 2 RB N sc in OFDM symbol l in an uplink, l ( + ) e j2πk f ( t N T ) CP, l s UL RB and k = k + N RB Nsc 2 1. The variable N equals 2048 and f = 75 khz. The OFDM symbols in a slot shall be transmitted in increasing order of l, starting with l = 0, where OFDM symbol l > 0 starts at time ( N = l 1 l 0 CP, l + N) Ts within the slot. <Table 6-13> lists the value of N CP, l that shall be used. <Table 6-13> OFDM parameters Configuration N Cyclic prefix length CP, l Normal cyclic prefix f = 75 khz 160 for l = for l = 1,2,..., Physical random access channel (xprach) Random access preamble subframe The physical layer random access preamble symbol, illustrated in (Figure 6-9) consists of a cyclic prefix of length T CP and a sequence part of length T SEQ. (Figure 6-9) Random access preamble 34

42 (Figure 6-10) denotes how the BS receives RACH from multiple UEs. These UEs occupy the same set of subcarriers. Each UE transmits for two symbols. UE1, UE3, UE9, etc. are located close to the BS and they transmit for ten symbols in total. UE2, UE4,, UE10, etc. are located at cell edge. These UEs also transmit in the same ten symbols. Due to the difference in distance, the signals of these UEs arrive at the BS T RTT time later than those of UE1, UE3,, UE5. (Figure 6-10) Reception of RACH signal at BS during RACH subframe The parameter values are listed in <Table 6-14>. <Table 6-14> Random access preamble parameters Preamble format TGP1 TCP TSEQ NSYM TGP *Ts 656*Ts 2048*Ts *Ts *Ts 1344*Ts 2048*Ts *Ts Due to extended cyclic prefix, there are ten symbols in this sub-frame for preamble format 0, and eigth symbols for preamble format 1 meant for 1km distance. Different subframe configurations for RACH are given below: <Table 6-15>Random access configuration PRACH configuration System Frame Number Subframe Number 0 Any 15, 40 1 Any 15 35

43 RACH signal is transmitted by a single antenna port The antenna port for RACH signal should have the same directivity as the one during which the measurement of the best BRS beam was conducted Preamble sequence generation The random access preambles are generated from Zadoff-Chu sequences with a length of 71. The th u root Zadoff-Chu sequence is defined by x u πun( n+ 1) j, ZC NZC ( n) = e 0 n N 1 where the length N ZC of the Zadoff-Chu sequence is 71. The value of the root is provided by higher layers. The random access preamble shall be mapped to resource elements according to kl, 2π j vk 3 a = f x( ne ), u {0,1,2} for format 0 ν {0} for format 1 k = n * (6 * n + 1), n {0,1...7} RACH RACH 1 if l is even f = f ' if l is odd f ' { 1,1} n = 0,1...,70, {(0,1),(2,3),( 4,5),(6,7),(8,9)} for format 0 l {(0,1),(2,3),(4,5),(6,7)} for format 1 where the cyclic shift, RACH band index n RACH and parameter f are provided by higher layers. As outlined by the equations above, the RACH subframe provides 8 RACH bands each occupying 6RBs. The parameter determines which band is used by the UE. During the synchroniation subframe, the UE identifies the symbol with the strongest beam. A set of parameters provided by the upper layers is used to map the symbol with the strongest beam to the RACH symbol index, as described in Higher layers determine the component carrier, in which the UE transmits the RACH signal. There are 48 preambles available in each cell. The set of 48 or 16 preambles 36

44 according to preamble format in a cell is found by combination of cyclic shift, OCC, and band index. Preamble index is allocated as follows: ' ( ) Preamble index = v+ N f + 1 / 2 + N 2 n where N v N N : number of cyclic shift v v =3, for format 0 =1, for format 1 v v RACH Procedure to Compute the Symbols of RACH Signal Layer 1 receives the following parameters, from higher layers: - System Frame Number, SFN - the BRS transmission period as defined in clause expressed in units of symbols - the number of symbols during the RACH subframe for which the BS applies different rx beams, where N N RACH RACH = 5, if preamble format = 0 = 4, if preamble format = 1 - number of RACH subframes M in each radio frame (here M can be 1 or 2 depending on RACH configuration) - index of RACH subframe m (here m ranges between 0 to M-1) - the symbol with the strongest sync beam, ranges between 0 and ). BestBeam S Sync (here the value of BestBeam S Sync The RACH subframes use the same beams as the synchronization subframes and in the same sequential order. Hence if the m-th RACH subframe occurs within a radio frame with the system frame number SFN, it will use the beams of the synchronization symbols identified by the set If BestBeam S Sync is among those symbols, the UE shall transmit the RACH preamble during the RACH subframe. The transmission should start at symbol 37

45 where denotes the number of symbols dedicated to a single RACH transmission. Here Baseband Signal Generation The baseband signal for RACH is generated in an OFDM manner according to section 5.6 with a tone spacing of and a cyclic prefix length of 656 or 1344 samples are inserted corresponding to the preamble format provided by higher layer Scheduling Request Collection during RACH Periods Scheduling request preamble slot Symbols for scheduling request (SR) are transmitted during the RACH subframe. They occupy a different set of subcarriers than those of RACH signal. Scheduling request is collected from any UE in a similar manner as the RACH signal. The scheduling request preamble, illustrated in (Figure 6-11)consists of a cyclic prefix of length T CP and a sequence part of length T SEQ. Both have the same values as their counterparts of the RACH preamble. (Figure 6-11) SR preamble <Table 6-16> Scheduling request preamble parameters Preamble configuration TCP TSEQ T s 2048 T s T s 2048 T s 38

46 Preamble sequence generation The scheduling request preambles are generated from Zadoff-Chu sequences. The network configures the set of preamble sequences the UE is allowed to use. The length of scheduling request preamble sequence is 71. The th u root Zadoff-Chu sequence is defined by x u πun( n+ 1) j, ZC NZC ( n) = e 0 n N 1, where N = 71. ZC Twelve different cyclic shifts of this sequence are defined to obtain scheduling request preamble sequence. The random access preamble shall be mapped to resource elements according to a k, l = f x k = n * (6 * N n = 0,1,...,70 1 f = f ' f ' { 1,1}. 2π j vk 12 u ( n) e if l is even if l is odd ν {0,1,2,...11} + 51), {(0,1),(2,3),(4,5),(6,7),(8,9)} l {(0,1),(2,3),(4,5),(6,7)}, SR for format 0 for format 1 As outlined by the equations above, the RACH subframe provides multiple subbands, each occupying 6 RBs, for transmitting SR; The parameter N SR determines which band is used by the UE. The values of and N SR are provided from higher layers. The symbol index l is calculated in the same way as described in Baseband signal generation The baseband signal for SR is generated in the same manner as RACH as outlined in

47 6.2.8 Modulation and upconversion Modulation and upconversion to the carrier frequency of the complex-valued OFDM baseband signal for each antenna port or the complex-valued xprach baseband signal is shown in (Figure 6-12). cos ( 2πf 0 t) Re { ( t) } s l (t) s l Split Filtering Im { ( t) } s l sin π ( 2 f 0 t) (Figure 6-12) Uplink modulation 6.3 Downlink Overview The smallest time-frequency unit for downlink transmission is denoted a resource element and is defined in clause Physical channels The following downlink physical channels are defined: - Physical Downlink Shared Channel, xpdsch - Physical Broadcast Channel, xpbch - Extended physical broadcast channel (epbch) - Physical Downlink Control Channel, xpdcch Physical signals A downlink physical signal corresponds to a set of resource elements used by the physical layer but does not carry information originating from higher layers. The following downlink physical signals are defined: 40

48 - Reference signal - Synchronization signal Slot structure and physical resource elements Resource grid The transmitted signal in each slot is described by one or several resource grids of DL RB N RB Nsc = 1200 subcarriers and DL N symb = 7 OFDM symbols. An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed. For beam sweeping transmission per an OFDM symbol, i.e. SS/xPBCH/BRS, an antenna port is defined within an OFDM symbol. For beam sweeping transmission per two consecutive OFDM symbols, i.e. epbch, an antenna port is defined within two OFDM symbols. For the other transmission, an antenna port is defined within a subframe. There is one resource grid per antenna port Resource elements Each element in the resource grid for antenna port p is uniquely identified by the index pair ( l) is called a resource element and k, DL RB in a slot where k = 0,..., NRB Nsc 1 and DL l = 0,..., N symb 1 are the indices in the frequency and time domains, respectively. Resource element ( l) k, on antenna port p corresponds to the complex value When there is no risk for confusion, or no particular antenna port is specified, the index p may be dropped. ( p) a k, l. 41

49 One downlink slot Tslot N DL symb OFDM symbols DL RB k = N N RB sc 1 Resource block N N DL symb RB sc resource elements subcarrier s RB sc DL N RB N subcarrier s RB N sc Resource element ( k, l) DL l = 0 l = N symb 1 k = 0 (Figure 6-13) Downlink resource grid Resource blocks Resource blocks are used to describe the mapping of certain physical channels to resource elements. A physical resource block is defined as DL N symb consecutive OFDM symbols in the time domain and N RB sc consecutive subcarriers in the frequency domain, where DL N symb and RB N sc are given by <Table 6-17>. A physical resource block thus consists of DL symb N N RB sc resource elements, corresponding to one slot in the time domain and 900 khz in the frequency domain. 42

50 Physical resource blocks are numbered from 0 to N RB 1 in the frequency domain. DL The relation between the physical resource block number n PRB in the frequency domain and resource elements ( k, l) in a slot is given by n PRB k = N RB sc <Table 6-17> Physical resource blocks parameters Configuration RB N sc DL N symb Normal cyclic prefix f = 75 khz 12 7 A physical resource-block pair is defined as the two physical resource blocks in one subframe having the same physical resource-block number nprb. The size of a virtual resource block group is four times that of a physical resource block. A pair of virtual resource block groups over two slots in a subframe is assigned together by a single virtual resource block group number, nvrb Virtual resource block groups of localized type DL Virtual resource block groups of localized type are numbered from 0 to N VRBG 1, where 4N = N DL VRBG DL RB. Virtual resource block group of index DL n VRBG of physical resource block pairs given by { 4 DL, 4 DL 1, 4 DL 2, 4 DL n 3} VRBG nvrbg + nvrbg + nvrbg + is mapped to a set Resource-element groups (xregs) xregs are used for defining the mapping of control channels to resource elements. Each OFDM symbol has 16 xregs. The xreg of index n xreg {0, 1,, 15} consists of resource elements ( k, l) with k = k + k 6m where - k RB 0 = 6 nxreg Nsc - 1 = { 0,1,4,5 } k, - = { 0,1,2,...,11} m,, 43

51 The OFDM symbol index is given by either of l = 0 or l = {0, 1} Guard Period for TDD Operation The guard time necessary for switching transmission direction is obtained by puncturing the OFDM symbol prior to an uplink transmission General structure for downlink physical channels The baseband signal representing a downlink physical channel is defined in terms of the following steps: - scrambling of coded bits in a codeword to be transmitted on a physical channel - modulation of scrambled bits to generate complex-valued modulation symbols - mapping of the complex-valued modulation symbols onto one or several transmission layers - precoding of the complex-valued modulation symbols on each layer for transmission on the antenna ports - mapping of complex-valued modulation symbols for each antenna port to resource elements - generation of complex-valued time-domain OFDM signal for each antenna port - analog beamforming based on the selected beam (Figure 6-14)Overview of physical channel processing Scrambling For an codeword q, the block of bits b ( q) (0),..., b ( q) ( M ( q) bit 1), where M ( q) bit is the number of bits in codeword q transmitted on the physical channel in one subframe, shall be scrambled prior to modulation, resulting in a block of scrambled bits ~ ( q) ~ ( q) (q) b (0),..., b ( M bit 1) according to ( i) = ( q) ( q ( b ( i) + c ( i) ) mod 2 ~ ( q) ) b 44

52 ( ) c q where the scrambling sequence ( i) is given by clause 7.2. The scrambling sequence generator shall be initialised at the start of each subframe, where the initialisation value of c init depends on the transport channel type according to c init = n RNTI q 2 n 13 s + = n s s 9 n / N mod20 cell ID for PDSCH Only one codewords can be transmitted in one subframe, i.e., q = Modulation For an codeword q, the block of scrambled bits ~ ( q) ~ ( q) (q) b (0),..., b ( M bit 1) shall be modulated as described in clause 7.1 using one of the modulation schemes in <Table 6-18>, resulting in a block of complex-valued modulation symbols d ( q) (0),..., d ( q) ( M (q) symb 1). <Table 6-18> Modulation schemes Physical channel xpdsch Modulation schemes QPSK, 16QAM, 64QAM Layer mapping The complex-valued modulation symbols for the codeword to be transmitted are mapped onto one or two layers. Complex-valued modulation symbols d ( q) (0),..., d ( q) ( M (q) symb 1) for codeword q shall be mapped onto the layers ( 0) ( υ 1) [ x ( i)... x ( i ] T x ( i) = ), layer i = 0,1,..., M symb 1 where υ is the number of layers and layer M symb is the number of modulation symbols per layer Layer mapping for transmission on a single antenna port For transmission on a single antenna port, a single layer is used, υ = 1 mapping is defined by (0) x ( i) = d (0) ( i), and the 45

53 with layer symb M = M (0) symb Layer mapping for spatial multiplexing For spatial multiplexing, the layer mapping shall be done according to <Table 6-19>. The number of layers υ is less than or equal to the number of antenna ports P used for transmission of the physical channel. <Table 6-19> Codeword-to-layer mapping for spatial multiplexing Number of layers Number of codewords Codeword-to-layer mapping i = layer 0,1,..., M symb 1 (0) (0) 1 1 x ( i) = d ( i) layer symb M = M (0) symb 2 1 x x (0) (1) ( i) = d ( i) = d (0) (0) (2i) (2i + 1) layer symb M = M (0) symb Layer mapping for transmit diversity For transmit diversity, the layer mapping shall be done according to <Table 6-20>. There is only one codeword and the number of layers υ is equal to the number of antenna ports P used for transmission of the physical channel. <Table 6-20> Codeword-to-layer mapping for transmit diversity Number of layers Number of codewords Codeword-to-layer mapping i = layer 0,1,..., M symb x x (0) (1) ( i) = d ( i) = d (0) (0) (2i) (2i + 1) layer symb M = M (0) symb Precoding ( 0) ( υ 1) x ( i) = [ x ( i)... x ( i) ] T The precoder takes as input a block of vectors, layer i = 0,1,..., M symb 1 from the layer mapping and generates a block of ( p) y ( i) = [... y ( i)...] T vectors, ap i = 0,1,..., M symb 1 to be mapped onto resources on each of ( ) the antenna ports, where y p ( i) represents the signal for antenna port p. 46

54 Precoding for transmission on a single antenna port For transmission on a single antenna port, precoding is defined by ( ) y p ( i) = x where p is the single antenna port number used for transmission of the physical (0) ( i) channel and ap i = 0,1,..., M symb 1, ap symb M = M layer symb Precoding for transmit diversity Precoding for transmit diversity is only used in combination with layer mapping for transmit diversity as described in clause The precoding operation for transmit diversity is defined for two antenna ports. For transmission on two antenna ports, p1 and p 2 indicated in the DCI format B1 the ( p ) ( p ) output y ( i) [ y ( i) y ( i) ] T 1 2 = by y y ( p y ( p y ( p ( p 1) 2 ), ap i = 0,1,..., M symb 1 1) (2i) 1 2 ) (2i) 1 = 0 (2i + 1) 2 0 (2i + 1) of the precoding operation is defined j 0 0 j (0) ( x ( i) ) (1) ( x ( i) ) (0) ( x ( i) ) 0 Re j Re j Im 0 Im( ( )) (1) x i layer 0,1,..., 1 for i = M symb with ap symb M = 2M layer symb. DM-RS 0 DM-RS 1 Precoding W v layers P antenna ports (Figure 6-15) DM-RS location for transmit diversity For transmit diversity, DM-RS is located after precoding with P antenna ports as illustrated in (Figure 6-15). 47

55 Precoding for spatial multiplexing using antenna ports with UE-specific reference signals Precoding for spatial multiplexing using antenna ports with UE-specific reference signals is only used in combination with layer mapping for spatial multiplexing as described in clause Spatial multiplexing using antenna ports with UE-specific reference signals supports up to two antenna ports to enable MU-MIMO capability and the set of antenna ports used is { 8,...,15} p. In the following let, p1 and p 2, denote the two antenna ports indicated by DCI format B2. For transmission of one layer on antenna port p 1, the precoding operation is defined by: ( p1 ) (0) y () i = x () i where ap i = 0,1,..., M symb 1, ap symb M = M layer symb. For transmission of two layers on antenna port p 1 and p 2, the precoding operation is defined by: y y ( p ) 1 ( p ) 2 ( i) x = ( i) x (0) (1) ( i) ( i) where ap i = 0,1,..., M symb 1, ap symb M = M layer symb Mapping to resource elements For each of the antenna ports used for transmission of the physical channel, the block of complex-valued symbols y ( p) (0),..., y ( p) ( M ap symb 1) shall conform to the downlink power allocation and be mapped in sequence starting with y ) to resource elements ( k, l) that are in the resource blocks assigned for transmission. The mapping to resource elements ( k, l) on antenna port p not reserved for other purposes shall be in increasing order of first the index k over the assigned physical resource blocks and then the index l, starting with the first slot in a subframe. ( p) (0 48

56 6.3.4 Physical downlink shared channel (xpdsch) The physical downlink shared channel shall be processed and mapped to resource elements as described in clause 6.3 with the following additions and exceptions: - The xpdsch shall be transmitted on υ antenna port(s) in the set p { 8,9,...,15}, where the number of layers used for transmission of the xpdsch υ is one or two. - xpdsch is not mapped to resource elements in the OFDM symbol carrying an xpdcch associated with the xpdsch. - xpdsch is not mapped to resource elements reserved for PCRS. If no PCRS is transmitted, xpdsch is mapped to the PCRS REs. If PCRS is transmitted in antenna port 60 or 61 or both, xpdsch is not mapped to the PCRS REs for both antenna port 60 and They are not defined to be used for UE-specific reference signals associated with xpdsch for any of the antenna ports in the set {8, 9,, 15}. - The index l in the first slot in a subframe fulfills l ldatastart - The index l in the second slot in a subframe fulfils Physical broadcast channel The Physical broadcast channel is transmitted using the same multiple beams used for beam reference signals in each OFDM symbol Scrambling The block of bits b ( 0),..., b ( M bit 1), where M bit, the number of bits transmitted on the physical broadcast channel, equals 5248, shall be scrambled with a cell-specific sequence prior to modulation, resulting in a block of scrambled bits b (0),..., b ( M bit 1) ~ ~ according to ~ b ( i) = + ( b( i) c( i) ) mod 2 where the scrambling sequence c(i) is given by clause 7.2. The scrambling sequence shall be initialised with cell c init = N ID in each radio frame fulfilling. 49

57 Modulation The block of scrambled bits b ~ ~ (0),..., b ( M bit 1) shall be modulated as described in clause 7.1, resulting in a block of complex-valued modulation symbols d ( 0),..., d ( M symb 1) for the physical broadcast channel.. <Table 6-21>specifies the modulation mappings applicable <Table 6-21> xpbch modulation schemes Physical channel xpbch Modulation schemes QPSK Layer mapping and precoding The block of modulation symbols d ( 0),..., d ( M symb 1) shall be mapped to layers according to one of clause and precoded according to clause , resulting in a ( ) block of vectors ~ 0 ( y i [ y ( i) ~ 1 ( ) = ~ y ) ( i) ] T, i = 0,..., Msymb 1. Then block of vectors ( 0 ) ( 1 [ ( ) ) (7) y ( i) y i y ( i) y ( i) ] T ( ) ~ p {0,2,4,6} y p ( i) = y and = is obtained by setting (1) ( i) for p {1,3,5,7}, where ( ) y p ( i) ( ) y p ( i) = ~ y (0) ( i) for represents the signal for antenna port p.the antenna ports p = 0 7 used for xpbch are identical to the antenna ports p = 0..7 used for the mapping of BRS according to Mapping to resource elements The block of complex-valued symbols is transmitted during 4 consecutive radio frames starting in each radio frame fulfilling. The block of complex-valued symbols are divided into 16 sub-block of complex-valued symbols, which is given by Sub-block 0 and 1:,, 50

58 Sub-block 2 and 3:,, Sub-block 4 and 5:,, Sub-block 6 and 7:,, Sub-block 8 and 9:,, Sub-block 10 and 11:,, Sub-block 12 and 13:,, Sub-block 14 and 15:, The sub-frames 0 and 25 in each radio frame shall be assigned to transmit xpbch together with synchronization signals. The sub-block of complex-valued symbols is repeated on each OFDM symbol in the subframe and it may be transmitted by different analog beams. The sub-blocks are repeated although transmitted with different information -- after every four radio frames, i.e., after every eight synchronization sub-frames. Focusing on four adjacent radio frames whose first eight bits of SFN are same and indexing the sub-frames of these radio frames from 0 to 199, sub-block 2i and 2i+1 are transmitted in sub-frame 25i where. The even indexed sub-block of complex-valued symbols transmitted shall be mapped in increasing order of the index in each OFDM symbol. The resource-element indices are given by: The odd indexed sub-block of complex-valued symbols transmitted in each subframe 51

59 shall be mapped in decreasing order of the index in each OFDM symbol. The resource-element indices are given by: where and Figures illustrates the resource elements used for xpbch according to the numerical definition Extended Physical broadcast channel The system information block to support standalone mode shall be transmitted on epbch via two antenna ports. The epbch is transmitted using the same multiple beams in consecutive OFDM symbols, where. The epbch is transmitted on a predefined or configured subframe. The essential system information for initial cell attachment and radio resource configuration shall be included in the system information block Scrambling The block of bits b ( 0),..., b ( M bit 1), where M bit, the number of bits transmitted on the extended physical broadcast channel, equals to 2000, shall be scrambled with a cellspecific sequence prior to modulation, resulting in a block of scrambled bits ~ ~ (0),..., b ( M bit 1) b according to ~ b ( i) = + ( b( i) c( i) ) mod 2 where the scrambling sequence shall be initialised with c(i) is given by clause 7.2. The scrambling sequence where ; ns is the slot number within a radio frame and is the OFDM symbol number within one subframe, and. 52

60 Modulation ~ ~ The block of scrambled bits b (0),..., b ( M bit 1) shall be modulated as described in clause 7.1, resulting in a block of complex-valued modulation symbols d ( 0),..., d ( M symb 1) for the extended physical broadcast channel.. <Table 6-22> specifies the modulation mappings applicable <Table 6-22>ePBCH modulation schemes. Physical channel epbch Modulation schemes QPSK Layer mapping and precoding The block of modulation symbols d ( 0),..., d ( M symb 1) shall be mapped to layers according to one of clause with (0) symb M = M symb and precoded according to clause , resulting in a block of vectors (50) (51) [ y ( i), y ( i ] T y ( i) = ), i = 0,..., Msymb 1, where y (50) ( i) and y (51) ( i) correspond to signals for antenna port 50 and 51, respectively epbch Configuration The epbch transmission periodicity is configured by xpbch, which is given by <Table 6-23>. <Table 6-23> epbch transmission periodicity Indication bit epbch transmission periodicty 00 epbch transmission is off N/A 01 40ms ms ms 16 The required number of subframes for epbch transmission is determined according to BRS transmission period, which is given by <Table 6-24>. 53

61 <Table 6-24> The number of subframes for epbch transmission according to BRS transmission period BRS transmission period # of subframes, 1 slot < 5ms 1 1 subframes = 5ms 2 2 subframes = 10ms 4 4 subframes = 20ms 8 When the epbch transmission is on, the multiple subframes for epbch transmission are configured in the radio frame fulfilling. The subframes in each configured radio frame shall be assigned to transmit epbch according to <Table 6-25>. <Table 6-25> Subframe configuration in each configured radio frame Value of Configured subframes in each configured radio frame 1 4 < 1 29, Mapping to resource elements In each OFDM symbol of the configured subframes, the block of complex-valued symbols is transmitted via two antenna ports. The block of complex-valued symbols is transmitted using identical beams in 2 consequtive OFDM symbols. The set of logical beam sweeping indices and their order across pairs of OFDM symbols in epbch subframes is identical to the set of logical beam indices and their order across OFDM symbols used for BRS transmission during BRS transmission period. The beam indexing initialization for epbch is such that the set of logical beam indices for all, is applied on the first symbol pair of the first epbch subframe in The block of complex-valued symbols transmitted in each OFDM symbol shall be mapped in increasing order of the index k excluding DM-RS associated with epbch. 54

62 The resource-element indices are given by where Physical downlink control channel (xpdcch) xpdcch formats The physical downlink control channel (xpdcch) carries scheduling assignments. A physical downlink control channel is transmitted using an aggregation of one or several consecutive enhanced control channel elements (CCEs) where each CCE consists of multiple resource element groups (REGs), defined in clause The number of CCEs used for one PDCCH depends on the PDCCH format and the number of REGs per CCE is given by <Table 6-26>. <Table 6-26> Supported xpdcch formats PDCCH Number of Number of resource-element Number of xpdcch format CCEs groups bits xpdcch multiplexing and scrambling ( 0),..., ( 1) The block of bits b b M bit to be transmitted on an xpdcch in a subframe shall be scrambled, resulting in a block of scrambled bits b (0),..., b ( M bit 1) according to ~ b ( i) = + ( b( i) c( i) ) mod 2 ~ ~ 55

63 where the UE-specific scrambling sequence c(i) is given by clause 7.2. The scrambling sequence generator shall be initialized with = ns c 2 + n 9 init 2 xpdcch ID where the quantity xpdcch n ID is given by - xpdcch cell n ID = NID if no value for ID n is provided by higher layers n = n otherwise. xpdcch - ID ID Modulation ~ ~ The block of scrambled bits b (0),..., b ( M tot 1) shall be modulated as described in clause 7.1, resulting in a block of complex-valued modulation symbols ( 0),..., d ( M symb 1) d. <Table 6-27> specifies the modulation mappings applicable for the physical downlink control channel. <Table 6-27> PDCCH modulation schemes Physical channel xpdcch Modulation schemes QPSK Layer mapping and precoding The layer mapping with space-frequency block coding shall be done according to <Table 6-28>. There is only one codeword and the two-layer transmission is used. <Table 6-28> Codeword-to-layer mapping for transmit diversity Number of layers Number of codewords Codeword-to-layer mapping layer i = 0,1,..., M symb 1 ( i) = d (2i) 2 1 x ( i) = d (2i + 1) x (0) (1) (0) (0) layer symb M = M (0) symb 2 For transmission on two antenna ports, p { 107,109} (107) (109) y ( i) = [ y ( i) y ( i) ] T, the output, ap i = 0,1,..., M symb 1 of the precoding operation is defined by 56

64 y y ( 107 y ) ( 2i) ( 109 y ) ( 2i ) ( 107 ) ( 2i + 1) ( 109 ) ( 2i + 1) = j 0 0 j ( 0 ( x ) ( i) ) ( 1 ( x ) ( i) ) ( 0 ( x ) ( i) ) ( 1 x ) ( i) 0 Re j Re j Im 0 Im( ) layer 0,1,..., 1 for i = M symb with ap symb M = 2M layer symb Mapping to resource elements The block of complex-valued symbols starting with y(0) meet all of the following criteria: y( 0),..., y( M symb 1) shall be mapped in sequence to resource elements ( k, l) on the associated antenna port which - they are part of the xregs assigned for the xpdcch transmission, and - l {0, 1} equals the OFDM symbol index The mapping to resource elements ( k, l) on antenna port p meeting the criteria above shall be in increasing order of the index k Reference signals The following types of downlink reference signals are defined: - UE-specific Reference Signal (DM-RS) associated with xpdsch - UE-specific Reference Signal (DM-RS) associated with xpdcch - CSI Reference Signal (CSI-RS) - Beam measurement Reference Signal (BRS) - Beam Refinement Reference Signal (BRRS) - Phase noise compensation reference signal, associated with transmission of PDSCH (PCRS) - Reference Signal (DM-RS) associated with epbch There is one reference signal transmitted per downlink antenna port UE-specific reference signals associated with xpdcch The demodulation reference signal associated with xpdcch is transmitted on the 57

65 same antenna port { 107,109} p as the associated xpdcch physical resource; Sequence generation For any of the antenna ports p { 107,109}, the reference-signal sequence defined by 1 1 r ( m) = =,..., 2 2 ( 1 2 c(2m) ) + j ( 1 2 c(2m + 1) ), m 01, 23. r(m) is The pseudo-random sequence c(n) is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with c n init s xpdcch ( ) ( 2n + 1) = ns / = n mod 20 s ID n xpdcch SCID at the start of each subframe where xpdcch n SCID = 2 and xpdcch n ID is configured by higher layers where the quantity xpdcch n ID is given by - xpdcch cell n ID = NID if no value for ID n is provided by higher layers n = n otherwise. xpdcch - ID ID Mapping to resource elements For the antenna port p { 107,109} shall be mapped to complex-valued modulation symbols where ( p) a k, l in a subframe according to a ( m ) r ( ') ( p) k, l = w p l m k = k m = m' k = ( m' mod 2) + 6 ' / 2 0 m mod 2 RB 0 6 nxreg Nsc 0 n < 16 xreg m'= 0,1,..., 23 The sequence w p (i) is given by <Table 6-29>. 58

66 <Table 6-29> The sequence (i) w p Antenna port p [ w p ( 0) wp (1) ] 107 [ +1 +1] 109 [ +1 1] UE-specific reference signals associated with xpdsch UE specific reference signals associated with xpdsch - are transmitted on antenna port(s) { 8,...,15} p indicated in DCI. - are present and are a valid reference for xpdsch demodulation only if the xpdsch transmission is associated with the corresponding antenna port; - are transmitted only on the physical resource blocks upon which the corresponding xpdsch is mapped. A UE-specific reference signal associated with xpdsch is not transmitted in resource elements ( k, l) in which one of the physical channels are transmitted using resource elements with the same index pair ( k, l) regardless of their antenna port p Sequence generation For any of the antenna ports p { 8,9,...,15} defined by r 1 1 max,, the reference-signal sequence r ( m) is DL ( m) = ( 1 2 c( 2m) ) + j ( 1 2 c( 2m + 1) ), m = 0,1,...,3N RB The pseudo-random sequence c(i) is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with c n init s = = n ( nscid ) ( n / 2 + 1) ( 2n + 1) s s mod 20 ID n SCID at the start of each subframe. The quantities ( i) ID n, i = 0, 1, are given by - ( ) ID cell ID n i = N if no value for n DMRS,i ID is provided by higher layers 59

67 - n ( i) n DMRS, i ID ID = otherwise The value of n SCID is zero unless specified otherwise. For an xpdsch transmission, n SCID is given by the DCI format associated with the xpdsch transmission Mapping to resource elements For antenna port p1 used for single port transmission, or ports { p 1, p 2 } used for twoport transmission in a physical resource block with frequency-domain index n PR B assigned for the corresponding xpdsch transmission, a part of the reference signal sequence r(m) shall be mapped to complex-valued modulation symbols ( p) a k, l in a subframe according to a ( p) = w ( k'' ) r( ''') k, l p k where RB k = 4m' + N sc nprb + k' 0 p { 8,12} 1 p { 9,13} k' = 2 p { 10,14} 3 p { 11,15} 0 if k mod8 < 4 k' ' = 1 if 4 k mod8 7 k k' '' = 4 2 l = 2,10 for high speed case m' = 0,1,2 Information indicating whether l = 2 or l = { 2,10} is signaled via higher layer signaling. The sequence w p (i) is given by <Table 6-30>. 60

68 <Table 6-30>The sequence (i) w p [ ] Antenna port p w p ( ) w ( 1) 0 p 8 [ +1 +1] 9 [ +1 +1] 10 [ +1 +1] 11 [ +1 +1] 12 [ +1 1] 13 [ +1 1] 14 [ +1 1] 15 [ +1 1] Resource elements ( k, l) used for transmission of UE-specific reference signals to one UE on any of the antenna ports in the set S, where S = { 8,12}, S = { 9,13}, S = { 10,14} or = { 11,15} S shall - not be used for transmission of xpdsch on any antenna port in the same subframe, and - not be used for UE-specific reference signals to the same UE on any antenna port other than those in S in the same subframe. (Figure 6-16) illustrates the resource elements used for UE-specific reference signals for antenna ports 8, 9, 10, 11, 12, 13, 14 and

69 R8 R9 R10 R11 62

70 R12 R13 R14 R15 (Figure 6-16) Mapping of UE-specific reference signals, antenna ports 8, 9, 10, 11, 12, 13, 14 and

71 CSI reference signals CSI reference signals are transmitted on 8 or 16 antenna ports using p = 16,..., 23 or p = 16,...,31 respectively. The antenna ports associated with CSI reference signals are paired into CSI-RS groups (CRGs). A CRG comprises of two consecutive antenna ports starting from antenna port p = 16. One or more of the CRGs is associated with zero-power and used as interference measurement resource. The transmission of CSI-RS is dynamically indicated in the xpdcch Sequence generation The reference-signal sequence s ( ) r l, n m is defined by ( m) = N max,dl ( 1 2 c(2m) ) + j ( 1 2 c(2m + 1) ), m = 0,1,..., 1 r l, n s RB where ns is the slot number within a radio frame and l is the OFDM symbol number within the slot. The pseudo-random sequence c(i) is defined in clause 7.2. The pseudo-random sequence generator shall at the start of each OFDM symbol be initialized with CSI CSI ( 7 ( n + 1) + l + 1) ( 2 N + 1) cinit = 2 N + s ID ID n s = n s mod 20 The quantity CSI N ID is configured to the UE using higher layer signaling Mapping to resource elements A CSI-RS allocation comprises of one symbol (symbol 12 or symbol 13) or two consecutive symbols (symbols 12 and 13). In a subframe used for CSI-RS transmission, the reference signal sequence r l n, ( m) s shall be mapped to complex-valued modulation symbols according to ( p) ak, l = rl, n ( m) s ( p) a k, l on antenna port p 64

72 0 for p {16,17,18,19,20,21,22,23} k = p m 8 for p {24,25,26,27,28,29,30,31} 5 for p {16,17,18,19,20,21,22,23} l =,and n s mod(2) = 1 6 for p {24,25,26,27,28,29,30,31} The mapping is illustrated in (Figure 6-17). (Figure 6-17)Mapping of CSI-RS for 2 symbol allocation A UE can be configured with a one symbol allocation or a two symbol allocation of a CSI resource. Each of the REs comprising a CSI resource are configured as either - CSI-RS resource (state 0); - CSI IM resource (state 1) A CSI resource configuration is configured via high layer signalling, and it comprises of a 16 bit bitmap indicating RE mapping described in <Tables 6-31>. The symbol allocation for a CSI resource(s) corresponding to a UE within a subframe is dynamically indicated by the resource configuration field of the DCI. 65

73 <Table 6-31> 16 bit bitmap which is indicating a CSI reosurce configuration k=0,8,16, l=12 k=1,9,17, l=12 k=2,10,18, l=12 k=3,11,19, l=12 k=4,12,20, l=12 k=5,13,21, l=12 k=6,14,22, l=12 State 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 k=0,8,16, l=13 k=1,9,17, l=13 k=2,10,18, l=13 k=3,11,19, l=13 k=4,12,20, l=13 k=5,13,21, l=13 k=6,14,22, l=13 State 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 k=7,15,23, l=12 k=7,15,23, l= Beam reference signals Beam reference signals are transmitted on one or several of antenna ports, p= Sequence generation The reference-signal sequence r l (m) is defined by where l =0,1,,13 is the OFDM symbol number within a subframe. The pseudorandom sequence c(i) is defined in clause 7.2. The pseudo-random sequence generator shall be initialised with at the start of each OFDM symbol, where and Mapping to resource elements The reference signal sequence shall be mapped to complex-valued modulation symbols ( p) a k, l used as reference symbols for antenna port p according to 66

74 where and the sequence w p (i) is defined in <Table 6-32>. <Table 6-32> The sequence w p (i) Antenna port p Resource elements ( k, l) used for transmission of beam reference signals on any of the antenna ports in a slot shall be shared based on the orthogonal cover code in <Table 6-32>. (Figures 6-18) illustrates the resource elements used for xpbch and beam reference signal transmission according to the numerical definition in and wp at each OFDM symbol. Also shown is the cover code on each resource element used for beam reference signal transmission on antenna port p. 67

75 Antenna port number 0 1 P 41 RBs 8 REs for BRS [ ] [ ] } DM-RS 18 RBs S S 4 REs for xpbch 41 RBs (Figure 6-18) Mapping of beam reference signals including xpbch and DM-RS Beam reference signal transmission period configuration The beam reference signal transmission period shall be configured by higher layers, which can be set to single slot, 1 subframe, 2 subframes or 4 subframes. In each configuration, the maximum # of opportunities for different TX beam training and the logical beam indexes are given by <Table 6-33>, <Table 6-33> Logical beam index mapping according to BRS transmission period BRS configuarion (Indication bits) BRS transmission period Maximum # of beam training opportunities Logical beam index 00 1 slot < 5ms 01 1 subframe = 5ms 10 2 subframes = 10ms 11 4 subframes = 20ms where is the total number of antenna ports. The logical beam index mapping according to the transmission period is given by <Table 6-34>, 68

76 <Table 6-34> Beam index mapping to OFDM symbol in each beam reference signal BRS configuarion st BRS Transmission Region BRS configuarion st BRS Transmission Region 2 nd BRS Transmission Region 3 rd BRS Transmission Region 4 th BRS Transmission Region where BRS transmission region is defined as a slot (in case of 00 ) or a subframe (in all configuration cases except 00 ) to transmit BRS, is antenna port number, port number is the logical beam index to transmit beam reference signals for antenna in i-th OFDM symbol in n-th beam reference signal slot or subframe. The beam indexing initialization is such that logical beam index for all is applied in for Beam refinement reference signals Beam refinement reference signals are transmitted on up to eight antenna ports using. The transmission and reception of BRRS is dynamically scheduled in the downlink resource allocation on xpdcch. 69

77 Sequence generation The reference signal can be generated as follows. where ns is the slot number within a radio frame; l is the OFDM symbol number within the slot; denotes a pseudo-random sequence defined by clause 7.2. The pseudo-random sequence generator shall at the start of each OFDM symbol be initialised with: The quantity is configured to the UE via RRC signalling Mapping to resource elements The reference signal sequence shall be mapped to complex-valued modulation symbols on antenna port according to where The BRRS can be transmitted in OFDM symbols l within a subframe, where l is configured by Indication of OFDM symbol index for CSI-RS/BRRS allocation in DCI format. On each Tx antenna port, BRRS may be transmitted with different Tx beam. 70

78 (Figure 6-19) Mapping of BRRS showing a 1 symbol allocation, e.g. l= Phase noise compensation reference signal, associated with transmission of PDSCH Phase noise compensation reference signals associated with xpdsch - are transmitted on antenna port(s) p = 60 and/or p = 61 signaled in DCI; - are present and are a valid reference for phase noise compensation only if the xpdsch transmission is associated with the corresponding antenna port; - are transmitted only on the physical resource blocks and symbols upon which the corresponding xpdsch is mapped; - are identical in all symbols corresponding to xpdsch allocation; Sequence generation For any of the antenna ports p { 60,61}, the reference-signal sequence r ( m) is 71