R_Frame_Structure_and_Air_Interface_Resources.pptx

1. Security Level:
HUAWEI TECHNOLOGIES CO., LTD.
www.huawei.com
NR Frame Structure and
Air Interface Resources
2018-05-20
5G Training Course

2. 2 Huawei Confidential
Contents
1 Numerology
2 Time-Domain Resources
3 Frequency-Domain Resources
4 Space-Domain Resources

3. 3 Huawei Confidential
Numerology (system parameter): refers to subcarrier spacing (SCS) in New Radio (NR) and related
parameters, such as the symbol length and cyclic prefix (CP) length.
Overview of NR Air Interface Resources (Time-, Frequency-
, and Space-domain Resources)
Numerology
Time-domain
resources
Frequency-domain
resources
Space-domain resources
Symbol
length
SCS
CP
Slot
1 slot = 14 symbols
Subframe Frame
REG CCE
RB RBG Bandwidth part
(BWP)
Carrier
1 subframe = 1 ms 1 frame = 10 ms
1 RB = 12 subcarriers
Antenna port
QCL
Basic scheduling unit
1 RBG = 2 to 16 RBs 1 BWP = Multiple RBs/RBGs
One or more BWPs can be
configured in one carrier.
1 REG = 1 PRB 1 CCE = 6 REGs
Data channel/control channel scheduling unit
Existed in LTE
Unchanged in NR
Existed in LTE
Modified in NR
Added in NR
The SCS determines
the symbol length
and slot length.
Codeword Layer
NR uses orthogonal frequency division multiple access (OFDMA), same as LTE does.
The main description dimensions of air interface resources are similar between LTE and NR except that BWP is added to NR in the frequency domain.

4. 4 Huawei Confidential
SCS–Background and Protocol-provided Definition
• Numerologies defined in 3GPP Release 15 (TS 38.211)
with SCS identified by the parameter µ.
• Available SCS for data channels and synchronization
channels in 3GPP Release 15
Parameter
µ
SCS CP
0 15 kHz Normal
1 30 kHz Normal
2 60 kHz Normal, extended
3 120 kHz Normal
4 240 kHz Normal
Based on LTE SCS of 15 kHz, a series of numerologies (mainly different SCS values) are supported to adapt to different requirements and channel characteristics.
Parameter
µ
SCS
Supported for Data
(PDSCH, PUSCH etc)
Supported for Sync
(PSS, SSS, PBCH)
0 15 kHz Yes Yes
1 30 kHz Yes Yes
2 60 kHz Yes No
3 120 kHz Yes Yes
4 240 kHz No Yes
*(LTE supports only 15 kHz SCS.)
• Background
– Service types supported by NR: eMBB, URLLC, mMTC, etc.
– Frequency bands supported by NR: C-band, mmWave, etc.
– Moving speed supported by NR: up to 500 km/h
• Requirements for SCS vary with service types,
frequency bands, and moving speeds.
– URLLC service (short latency): large SCS
– Low frequency band (wide coverage): small SCS
– High frequency band (large bandwidth, phase noise): large
SCS
– Ultra high speed mobility: large SCS
• NR SCS design principle
– NR supports a series of SCS values.

5. 5 Huawei Confidential
• Coexistence of different SCS values and FDM
– The eMBB and URLLC data channels use different SCS
values and coexist through FDM.
– The PBCH and PDSCH/PUSCH use different SCS values
and coexist through FDM.
SCS: Application Scenarios and Suggestions
• Impact of SCS on coverage, latency, mobility, and phase noise
– Coverage: The smaller the SCS, the longer the symbol length/CP, and the
better the coverage.
– Mobility: The larger the SCS, the smaller the impact of Doppler shift, and
the better the performance.
– Latency: The larger the SCS, the shorter the symbol length/latency.
– Phase noise: The larger the SCS, the smaller the impact of phase noise,
and the better the performance.
• SCS application suggestions for different frequency bands
(eMBB service data channel):
SCS (kHz) 15 30 60 120 240
3.5 GHz
28 GHz
Coverage
Mobility
Latency
Coverage
Mobility
Latency
good bad
good
bad
good
bad
good bad
good
bad
good
bad
good
bad
Phase Noise
It is recommended that the SCS be 30 kHz for C-band and 120 kHz for 28 GHz. Different SCS values and coexistence through FDM are supported.

6. 6 Huawei Confidential
SCS Configuration for Physical Channels and
Signals
Channel SCS Defined in 3GPP Release 15 Configuration Scheme
Initial
access
SS/PBCH
Sub-6 GHz: 15/30 kHz
Above-6 GHz: 120/240 kHz
RAN4 defines the
default SCS for each
frequency band (see
Table 5.4.3.3-1 in 3GPP
TS 38.104).
RMSI, Msg2/4 (PDSCH)
Sub-6 GHz: 15/30 kHz
Above-6 GHz: 60/120 kHz
MIB
Msg1 (PRACH), Msg3
(PUSCH)
Long PRACH: SCS = {1.25 5} kHz
Short PRACH: SCS = {15, 30, 60,
120} kHz, where: sub-6 GHz: 15/30
kHz, above-6 GHz: 60/120 kHz
RMSI
RRC
connected
mode
PDSCH/PDCCH/CSI-RS
Sub-1 GHz: 15/30 kHz
1 GHz to 6 GHz: 15/30/60 kHz
Above-6 GHz: 60/120 kHz
RRC signaling
PUSCH/PUCCH/SRS
Sub-1 GHz: 15/30 kHz
1 GHz to 6 GHz: 15/30/60 kHz
Above-6 GHz: 60/120 kHz
RRC signaling
The protocol-defined SCS is used by the synchronization and broadcast channels involved in initial access. The SCS for other channels is
configured in the MIB, RMSI, and RRC signaling.
gNodeB UE
SS/PBCH
SCS: protocol-defined default value
PRACH
SCS: configured in RMSI
RMSI (SIB1)
SCS: configured in MIB
Msg2 (random access response)
SCS: same as RMSI
Msg3 (transmitted over PUSCH)
SCS: configured in RMSI
Msg4 (transmitted over PDSCH)
SCS: same as RMSI
DL: PDSCH/PDCCH/CSI-RS
SCS: configured in RRC signaling
UL: PUSCH/PUCCH/SRS
SCS: configured in RRC signaling

7. 7 Huawei Confidential
Contents
2 Time-Domain Resources: CP, Symbol, Slot, Frame Structure
1 Numerology
3 Frequency-Domain Resources
4 Space-Domain Resources

8. 8 Huawei Confidential
Time-domain Resources: Radio Frame, Subframe,
Slot, Symbol
Radio frame
Subframe Subframe Subframe
...
Slot Slot Slot
...
Inherited from LTE and has a
fixed value of 1 ms
Symbol Symbol Symbol
...
Symbol
Inherited from LTE and has a
fixed value of 10 ms
Basic unit for modulation
Minimum unit for data scheduling
Sampling
point ...
Sampling
point
Sampling
point Basic time unit at the physical layer
In the time domain, slot is a basic scheduling unit for data channels. The concepts of radio frames and subframes are the
same as those in LTE.

9. 9 Huawei Confidential
Symbol Length–Determined by SCS
 Symbol = CP + Data
 SCS vs CP length/symbol length/slot length
– Length of OFDM symbols in data: T_data = 1/SCS
– CP length: T_cp = 144/2048 x T_data
– Symbol length (data+CP): T_symbol = T_data +T_cp
– Slot length: T_slot = 1 / 2^(µ)
Parameter/Numerology (µ) 0 1 2 3 4
SCS (kHz):
SCS = 15 x 2^(µ)
15 30 60 120 240
OFDM Symbol Duration (µs):
T_data = 1/SCS
66.67 33.33 16.67 8.33 4.17
CP Duration (µs):
T_cp = 144/2048 x T_data
4.69 2.34 1.17 0.59 0.29
OFDM Symbol Including CP (µs):
T_symbol = T_data + T_cp
71.35 35.68 17.84 8.92 4.46
Slot Length (ms):
T_slot = 1/2^(µ)
1 0.5 0.25 0.125 0.0625
CP data …
T_slot = 1 ms (14 symbols)
SCS
=
15
kHz
…
T_slot = 0.5 ms (14 symbols)
SCS
=
30
kHz
…
T_slot = 0.125 ms (14 symbols)
SCS
=
120
kHz
T_symbol
T_symbol
T_symbol
A symbol consists of a CP and data. The length of the data is the reciprocal of SCS. The larger the SCS, the smaller the symbol length and the slot length.

10. 10 Huawei Confidential
CP: Background and Principles
 Multipath latency extension
– The width extension of the received signal pulse caused by multipath is the
difference between the maximum transmission latency and the minimum
transmission latency. The latency extension varies with the environment, terrain,
and clutter, and does not have an absolute mapping relationship with the cell
radius.
 Impact
– Inter-Symbol Interference (ISI) is generated, which severely affects the
transmission quality of digital signals.
– Inter-Channel Interference (ICI) is generated. The orthogonality of the subcarriers
in the OFDM system is damaged, which affects the demodulation on the receive
side.
 Solution: CP for reduced ISI and ICI
– Guard intervals reduce ISI. A guard interval is inserted between OFDM symbols,
where the length (Tg) of the guard interval is generally greater than the maximum
latency extension over the radio channel.
– CP is inserted in the guard interval to reduce ICI. Replicating a sampling point
following each OFDM symbol to the front of the OFDM symbol. This ensures that
the number of waveform periods included in a latency copy of the OFDM symbol
is an integer in an FFT period, which guarantees subcarrier orthogonality.
CPs between OFDM symbols resolve ISI and ICI caused by multipath propagation.

11. 11 Huawei Confidential
 CP length for different SCS values:
 Key factors that determine the CP length
– Multipath latency extension: The larger the multipath latency extension,
the longer the CP.
– OFDM symbol length: Given the same OFDM symbol length, a longer
CP indicates a larger system overhead.
 NR CP design principle
– Same overhead as that in LTE
– Aligned symbols between different SCS values and the reference
numerology (15 kHz)
CP: Protocol-defined
Parameter
µ
SCS
(kHz)
CP
(µs)
0 15 NCP: 5.2 µs for l = 0 or 7; 4.69 µs for others
1 30 NCP: 2.86 µs for l = 0 or 14; 2.34 µs for others
2 60
NCP: 1.69 µs for l = 0 or 28; 1.17 µs for others
Extended CP (ECP): 4.17 µs
3 120 NCP: 1.11 µs for l = 0 or 56; 0.59 µs for others
4 240 NCP: 0.81 µs for l = 0 or 112; 0.29 µs for others
c
cp
cp T
N
T 

0 1 2 3
1 1
1





























2
7
and
0
prefix,
cyclic
normal
2
144
2
7
or
0
prefix,
cyclic
normal
16
2
144
prefix
cyclic
extended
2
512
,
CP
l
l
l
l
N l
– If normal CP (NCP) is used, the CP of the first symbol
present every 0.5 ms is longer than that of other symbols.
The CP length in NR is designed in line with the same principles as LTE. Overheads are the same between NR and LTE.
Aligned symbols are ensured between different SCS values and the SCS of 15 kHz.

12. 12 Huawei Confidential
 Frame structure architecture:
 Example: SCS = 30 kHz/120 kHz
Frame Structure: Architecture
SCS
(kHz)
Slot Configuration (NCP)
Number of
Symbols/Slot
Number of
Slots/Subframe
Number of Slots
/Frame
15 14 1 10
30 14 2 20
60 14 4 40
120 14 8 80
240 14 16 160
480 14 32 320
 Frame length: 10 ms
– SFN range: 0 to 1023
 Subframe length: 1 ms
– Subframe index per system frame: 0 to 9
 Slot length: 14 symbols
Slot Configuration (ECP)
60 12 4 40
1 frame = 10 ms = 10 subframes = 20 slots
1 subframe = 1 ms = 2 slots
1 slot = 0.5 ms = 14 symbols
SCS
=
30
kHz
SCS
=
120
kHz
1 frame = 10 ms = 10 subframes = 80 slots
1 subframe = 1 ms = 8 slots
1 slot = 0.125 ms = 14 symbols
The lengths of a radio frame and a subframe in NR are consistent with those in LTE. The number of slots in each subframe is determined by
the subcarrier width.

13. 13 Huawei Confidential
X
Slot Format and Type
 Slot structure (section 4.3.2 of 3GPP TS 38.211)
– Downlink, denoted as D, for downlink transmission
– Flexible, denoted as X, for uplink or downlink
transmission, GP, or reserved.
– Uplink, denoted as U, for uplink transmission
 Main slot types
– Case 1: DL-only slot
– Case 2: UL-only slot
– Case 3: flexible-only slot
– Case 4: mixed slot (at least one downlink slot
and/or one uplink slot)
D U
D X X U
D X U D X U D X U
D X U
Case 1: DL-only slot Case 2: UL-only slot Case 3: flexible-only slot
 Compared with LTE, NR has the following slot format features:
– Flexibility: symbol-level uplink/downlink adaptation in NR and
subframe-level in LTE
– Diversity: More slots are supported in the NR system to cope
with more scenarios and service types.
 Examples of application scenarios of different slots:
Case 4-1 Case 4-2
Case 4-3 Case 4-4 Case 4-5
Slot Type Application Scenario Example
Case 1 DL-heavy transmission
Case 2 UL-heavy transmission
Case 3
1. Forward compatibility: Resources are reserved for future services.
2. Adaptive adjustment of uplink and downlink resources: such as dynamic TDD
Case 4-1 1. Forward compatibility: Resources are reserved for future services.
2. Flexible data transmission start and end locations: such as unlicensed
frequency bands and dynamic TDD
Case 4-2
Case 4-3 Downlink self-contained transmission
Case 4-4 Uplink self-contained transmission
Case 4-5 Mini-slot (seven symbols) for URLLC services
The number of uplink and downlink symbols in a slot can be flexibly configured. In Release 15, a mini-slot contains 2, 4, or 7 symbols for data
scheduling in a short latency or a high frequency band scenario.

14. 14 Huawei Confidential
 The self-contained slot or subframe type is
not defined in 3GPP specifications.
 The self-contained slots or subframes
discussed in the industry and literature are
featured as follows:
– One slot or subframe contains uplink part, downlink part, and GP.
– Downlink self-contained slot or subframe: includes downlink data and
corresponding HARQ feedback.
– Uplink self-contained slot or subframe: includes uplink scheduling
information and uplink data.
Self-contained Slots/Subframes
D U
UL control or SRS
D U
DL control
ACK/NACK
UL grant
 Self-contained slot/subframe design objectives
– Faster downlink HARQ feedback and uplink data scheduling: reduced RTT
– Shorter SRS transmission period: to cope with fast channel changes for
improved MIMO performance
 Problems in application
– The small GP limits cell coverage.
– High requirements on UE hardware processing:
• Release 15 defines two types of UE processing capabilities. The
baseline capability is 10 to 13 symbols if the SCS is 30 kHz and self-
contained transmission is not supported.
– Frequent uplink/downlink switching increases the GP overhead.
– In the downlink, only the retransmission latency can be reduced.
• E2E latency depends on many factors, including the core network and
air interface.
• The latency on the air interface side is also limited by the
uplink/downlink frame configuration, and the processing latency on the
gNodeB and UE.
D U
Downlink data processing time:
Part of the GP needs to be reserved for
demodulating downlink data and
generating ACK/NACK feedback.
Air interface
round-trip latency
Self-contained subframes reduce the RTT latency on the RAN side but limits cell coverage. Therefore, high requirements
are posed on hardware processing capabilities of UEs.

15. 15 Huawei Confidential
 Mini-slot: fewer than 14 symbols in the time
domain
 Basic scheduling units are classified into
the following types:
– Slot-based: The basic scheduling unit is slot, and the
time-domain length is 14 symbols.
– Non-slot-based: The basic scheduling unit is mini-slot. In
Release 15, the time-domain length is 2, 4, or 7 symbols.
Mini-slot: Support for the Length of 2, 4, or 7 Symbols in
Release 15
 Application scenario
– Short-latency scenario: reduces the scheduling
waiting latency and transmission latency.
– Unlicensed frequency band: Data can be transmitted
immediately after listen before talk (LBT).
– mmWave scenario: TDM is applied for different UEs
in a slot.
1. URLLC for low latency
2. eMBB in unlicensed band
3. mmWave
Release 15 supports mini-slots with the length of 2, 4, or 7 symbols, which can be applied in short latency and mmWave
scenarios.
PDCCH
PDSCH (mini-slot)
PDSCH
(mini-slot)
Slot-based
Non-slot-based
PDSCH

16. 16 Huawei Confidential
UL/DL Slot/Frame Configuration
 Configuration: in line with section 11.1 of 3GPP TS 38.213
– Layer 1: semi-static configuration through cell-specific RRC signaling
– SIB1: UL-DL-configuration-common and UL-DL-configuration-common-Set2
– Period: {0.5,0.625,1,1.25,2,2.5,5,10} ms, SCS dependent
– Layer 2: semi-static configuration through UE-specific RRC signaling
– Higher layer signaling: UL-DL-configuration-dedicated
– Period: {0.5,0.625,1,1.25,2,2.5,5,10} ms, SCS dependent
– Layer 3: dynamic configuration through UE-group SFI
– DCI format 2_0
– Period: {1,2,4,5,8,10,20} slots, SCS dependent
– Layer 4: dynamic configuration through UE-specific DCI
– DCI format 0, 1
 Main characteristics: hierarchical configuration or
separate configuration of each layer
– Different from LTE, the NR system supports UE-specific
configuration, which delivers high flexibility.
– Support for symbol-level dynamic TDD
D D D
X D
X D
X D
U
D
X X D
X D
X
D
X X D
X D
X
D
D D
U
D D D
U
D
D D D
D D
X
D
D D
U
D D D
U
D
D D D
D
D
D D
U
D D D
U
D
1. Cell-specific RRC configuration
2. UE-specific RRC configuration
3. SFI
4. DCI
 Hierarchical configuration
 Separate layer configuration
D
D D D
D
D
D D
U
D D D
U
D
Cell-specific RRC configuration/SFI
D
Frame configuration supports hierarchical configuration through RRC signaling and DCI to deliver symbol-level dynamic
TDD and high flexibility.
If X slots/symbols are configured at the upper layer, D or U slots/symbols
are also configured at the lower layer.

17. 17 Huawei Confidential
 Single-period configuration: DDDSU
 Dual-period configuration: DDDSU DDSUU
UL/DL Slot/Frame Configuration: Cell-specific
Semi-static Configuration
X: DL/UL assignment periodicity
x1: full DL slots y1: full UL slots
x2: DL symbols
y2: UL symbols
 Cell-specific RRC signaling parameters
– Parameter: SIB1
– UL-DL-configuration-common: {X, x1, x2, y1, y2}
– UL-DL-configuration-common-Set2: {Y, x3, x4, y3, y4}
– X/Y: assignment period
– {0.5, 0.625, 1, 1.25, 2, 2.5, 5, 10} ms
– 0.625 ms is used only when the SCS is 120 kHz. 1.25 ms is used when
the SCS is 60 kHz or larger. 2.5 ms is used when the SCS is 30 kHz or
larger.
– A single period or two periods can be configured.
– x1/x3: number of downlink-only slots
– {0,1,…, number of slots in the assignment period}
– y1/y3: number of uplink-only slots
– {0,1,…, number of slots in the assignment period}
– x2/x4: number of downlink symbols following downlink-only slots
– {0,1,…,13}
– y2/y4: number of uplink symbols followed by uplink-only slots
– {0,1,…,13}
D D
D
D D
U
D D D
D
U
D D
D
X: DL/UL assignment periodicity
x1 y1
x2
y2
D D
D
D D
U
D D D
D
U
D D
U
Y: DL/UL assignment periodicity
x3 y3
x4
y4
Cell-specific semi-persistent configuration supports limited configuration period options, and flexible static configuration of
DL/UL resources are realized through RRC signaling.

18. 18 Huawei Confidential
UL/DL Slot Configuration: Dynamic Configuration
Through SFI
 Slot Format Indicator (SFI) is transmitted over the group-common PDCCH.
– SFI is identified by indexes in the following tables (reference: Table 4.3.2-3 in 3GPP TS 38.211).
The slot type can be notified to the UE through SFI over the PDCCH to dynamically set the slot/frame configuration.

19. 19 Huawei Confidential
 Features of the four configuration schemes
 Typical configuration schemes for commercial use:
– Unified static network-wide frame configuration with the configuration period within the protocol-specified range: configured in cell-
specific RRC signaling.
– Unified static network-wide frame configuration with the configuration period outside the protocol-specified range: configured in cell-
specific and UE-specific RRC signaling. SFI- and DCI-indicated configurations can be added.
– Dynamic TDD: Cell-specific RRC+SFI/DCI configurations or direct SFI/DCI configurations
Comparison Among and Application of Different
Frame Configuration Schemes
Configuration Scheme Feature and Resource Configuration Priority
Cell-specific RRC signaling
Features: Cell-specific+static, or semi-persistent resource configuration
Resource configuration priority: Highest. Cell-specific-signaling-indicated D or U cannot be modified through other configurations.
UE-specific RRC signaling
Features: UE-specific+static, or semi-persistent resource configuration
Resource configuration priority: High. The X configurations indicated in cell-specific signaling can be further configured. UE-specific-signaling-
indicated D or U cannot be modified through SFI/DCI.
SFI
Features: UE- or UE group-specific+periodic (1–20 slots) dynamic configuration
Resource configuration priority: Low. The X configurations indicated in cell-specific or UE-specific signaling can be further configured.
DCI
Features: UE-specific+slot-specific dynamic configuration
Resource configuration priority: Very low. The X configurations indicated in the cell-specific signaling/UE-specific signaling/SFI can be further
configured.
Different configuration schemes are used to adapt to scenarios and requirements. The cell-specific RRC signaling
configuration scheme delivers unified static network-wide frame configuration.

20. 20 Huawei Confidential
Contents
2 Time-Domain Resources
1 Numerology
3 Frequency-Domain Resources: RB, RBG, REG, CCE, BWP
4 Space-Domain Resources

21. 21 Huawei Confidential
Basic Concepts of Frequency-Domain Resources
OFDM symbols
One subframe
0

l
RB
sc
RB
N
N

subcarriers
RB
sc
N
subcarriers
Resource element
)
,
( l
k
0

k
1
RB
sc
,
max
RB, 
 N
N
k x

1
2
14 

 
l

,
subframe
symb
N
Resource
block
Resource
Grid
Resource
Block
Resource Element
 Resource Grid (RG)
– Physical-layer resource group, which is defined separately for
the uplink and downlink (RGs are defined for each
numerology).
– Frequency domain: available RB resources within the
transmission bandwidth 𝑁RB
– Time domain: 1 subframe
 Resource Block (RB)
– Basic scheduling unit for data channel resource allocation in
the frequency domain
– Frequency domain: 12 consecutive subcarriers
 Resource Element (RE)
– Minimum granularity of physical-layer resources
– Frequency domain: 1 subcarrier
– Time domain: 1 OFDM symbol
In NR, an RB corresponds to 12 subcarriers (same as LTE) in the frequency domain. The frequency-domain width is related
to SCS and is calculated using 2µ x 180 kHz.

22. 22 Huawei Confidential
 Basic scheduling unit for control
channels: CCE
– RE Group (REG): basic unit for control channel
resource allocation
– Frequency domain: 1 REG = 1 PRB (12 subcarriers)
– Time domain: 1 OFDM symbol
– Control Channel Element (CCE): basic scheduling unit
for control channel resource allocation
– Frequency domain: 1 CCE = 6 REGs = 6 PRBs
– CCE aggregation level: 1, 2, 4, 8, 16
PRB/RBG and CCE: Frequency-domain Basic
Scheduling Units
 Basic scheduling unit for data channels:
PRB/RBG
– Physical RB (PRB): Indicates the physical resource block in the
BWP.
– Frequency domain: 12 subcarriers
– Resource Block Group (RBG): a set of physical resource blocks
– Frequency domain: The size depends on the number of RBs
in the BWP.
BWP Size (RBs)
RBG Size
Config 1 Config 2
1–36 2 4
37–72 4 8
73–144 8 16
145–275 16 16
In the frequency domain, the PRB or an RBG is a basic scheduling unit for data channels, and the CCE is a basic scheduling
unit for control channels.
RB0 RB1 RB2 RB3 RB4 RB5 RB6 RB7 RB8 RB9 RB10 RB11 RB12 …
RBG0 RBG1 RBG2 …
RB
RBG
4 RBs
REG DMRS
DMRS
DMRS
CCE PRB

23. 23 Huawei Confidential
Channel Bandwidth and Transmission Bandwidth
 Channel bandwidth
– Channel bandwidth supported by the FR1 frequency
band (450 MHz to 6000 MHz): 5 MHz (minimum),
100 MHz (maximum)
– Channel bandwidth supported by the FR2 frequency
band (24 GHz to 52 GHz): 50 MHz (minimum), 400
MHz (maximum).
 Maximum transmission bandwidth
(maximum number of available RBs)
– Determined by the channel bandwidth and data
channel SCS.
– Defined on the gNodeB side and UE side separately.
For details about the protocol-configuration of the
UE side, see the figure on the right.
 Guard bandwidth
– With F-OFDM, the guard bandwidth decreases to
about 2% in NR (corresponding to 30 kHz SCS, 100
MHz channel bandwidth).
Compared with the guard bandwidth (10%) in LTE, NR uses F-OFDM to reduce the guard bandwidth to about 2%.
Active RBs
Guard band

24. 24 Huawei Confidential
Maximum Number of Available RBs and Spectrum Utilization
 Spectrum utilization = Maximum transmission bandwidth/Channel bandwidth
– Maximum transmission bandwidth on the gNodeB side: See Table 5.3.2-1 and 5.3.2-2 in 3GPP TS 38.104.
– Maximum transmission bandwidth on the UE side: See 3GPP TS 38.101-1 and TS 38.101-2.
SCS
[kHz]
5
MHz
10
MHz
15
MHz
30
MHz
20
MHz
25
MHz
40
MHz
50
MHz
60
MHz
70
MHz
80
MHz
90
MHz
100
MHz
NRB and Spectrum Utilization (FR1:400 MHz to 6000 MHz)
15
25 52 79 [160] 106 133 216 270 N/A N/A N/A N/A N/A
90% 93.6% 94.8% [96%] 95.4% 95.8% 97.2% 97.2%
30
11 24 38 [78] 51 65 106 133 162 [189] 217 [245] 273
79.2% 86.4% 91.2% 91.8% 93.6% 95.4% 95.8% 97.2% 97.7% 98.3%
60
N/A 11 18 [38] 24 31 51 65 79 [93] 107 [121] 135
79.2% 86.4% 86.4% 893% 91.8% 93.6% 94.8% 93.6% 97.2%
SCS
[kHz]
50 MHz 100 MHz 200 MHz 400 MHz
NRB and Spectrum Utilization (FR2: 24
GHz to 52 GHz)
60
66 132 264 N/A
95% 95% 95%
120
32 66 132 264
92.2% 95% 95% 95%
Spectrum utilization is related to the channel bandwidth. The higher the bandwidth, the higher the spectral efficiency.

25. 25 Huawei Confidential
RB Location Index and Indication
 BWP is introduced to the NR system, which causes
differences in the RB location index and indication
from LTE.
 Related concepts (section 4.4 of 3GPP TS 38.211)
– RG: In the frequency domain, an RG includes all available
RBs within the transmission bandwidth.
– BWP: new concept introduced in the NR system. It refers to
some RBs in the transmission bandwidth and is configured
by the gNodeB.
– Point A: basic reference point of the RG
– Defined for the uplink, downlink, PCell, SCell, and SUL separately
– Point A = Reference Location + Offset
– For details about the reference location and offset for different
reference points, see the figure on the right.
– Common RB (CRB): index in the RG
– The center of 0# subcarrier of CRB#0 is aligned with that of Point A.
– Physical RB (PRB): index in the BWP
– Index: 0 to
– Relationship between PRB and CRB:
is the number of CRBs between the BWP start position and
CRB#0.
Point A Reference Location Offset
PCell DL
(TDD/FDD)
SSB start location
UEs perform blind detection to obtain this
information.
UEs are informed of this information through the RMSI.
Parameter:
PRB-index-DL-common
PCell UL
(TDD)
Same as Point A for the PCell downlink
UEs are informed of this information through the RMSI.
Parameter:
PRB-index-UL-common
PCell UL
(FDD)
Frequency-domain location of the ARFCN
UEs are informed of this information
through the RMSI (SIB1).
UEs are informed of this information through the RMSI.
Parameter:
PRB-index-UL-common
SCell
DL/UL
Frequency-domain location of the ARFCN
UEs are informed of this information
through the SCell configuration message.
UEs are informed of this information through RRC
signaling.
Parameter:
PRB-index-DL-Dedicated
PRB-index-UL-Dedicated
SUL
Frequency-domain location of the ARFCN
UEs are informed of this information
through the SCell configuration message.
UEs are informed of this information through RRC
signaling.
Parameter:
PRB-index-SUL-common
0 1 2 3 … 0 1 2 3 …
BWP
Offset
Reference
Location
Point A
0
0
CRB Index in RG
PRB Index in BWP
RG
Freq.
Point A is the basic reference point in the RG. CRB is the RB index in the RG, and PRB is the RB index in the BWP.
1
size
BWP, 
i
N
start
BWP,
PRB
CRB i
N
n
n 

start
BWP,i
N

26. 26 Huawei Confidential
 Definition and characteristics
– The Bandwidth Part (BWP) is introduced in NR. It is a set of contiguous bandwidth resources configured by the gNodeB for UEs to
achieve flexible transmission bandwidth configuration on the gNodeB side and UE side. Each BWP corresponds to a specific numerology.
– BWP is specific to UEs (BWP configurations vary with UEs). UEs do not need to know the transmission bandwidth on the gNodeB side
but only needs to support the configured BWP bandwidth.
 Application scenarios
– Scenario#1: UEs with a small bandwidth access a large-bandwidth network.
– Scenario#2: UEs switch between small and large BWPs to save battery power.
– Scenario#3: The numerology is unique for each BWP and service-specific.
BWP Definition and Application Scenarios
BWP
BWP Bandwidth
Carrier Bandwidth
#1
BWP 2
#2
BWP 1
Numerology 1
BWP1
Carrier Bandwidth
#3
Numerology 2
BWP 2
Carrier Bandwidth
BWP is a set of contiguous bandwidth resources configured by the gNodeB for UEs. The application scenario examples are as follows: UEs supporting small
bandwidths, power saving, and support for FDM on services of different numerologies.

27. 27 Huawei Confidential
BWP Types
 BWP types
– Initial BWP: configured in the initial access phase. Signals and channels are transmitted in the initial BWP during initial access.
– Dedicated BWP: configured for UEs in RRC_CONNECTED mode. A maximum of four dedicated BWPs can be configured for a UE.
– Active BWP: one of the dedicated BWPs activated by a UE in RRC_CONNECTED mode. According to Release 15, a UE in
RRC_CONNECTED mode can have only one active BWP at a given time.
– Default BWP: It is one of the dedicated BWPs and is indicated by RRC signaling. After the BWP inactivity timer expires, the UE in
RRC_CONNECTED mode switches to the default BWP.
Carrier Bandwidth
Initial BWP
Carrier Bandwidth
UE1 Active BWP
Random Access Procedure RRC Connected Procedure
Carrier Bandwidth
default
Default
UE1
Dedicated
BWPs
UE1 UE2
Default
UE2
Dedicated
BWPs
UE2 Active BWP UE2 Active BWP
UE1 Active BWP
UE2 BWP inactivity
timer
PDCCH indicating downlink assignment
UE2 switches to the default
BWP.
Active
Active
Switch

28. 28 Huawei Confidential
Initial BWP Configuration
 Initial DL BWP definition and configuration
– Function: The PDSCH used to transmit RMSI, Msg2, and Msg4 must be
transmitted in the initial active DL BWP.
– Definition of the initial DL BWP: frequency-domain location and bandwidth of
RMSI CORESET (control channel resource set) and a numerology
corresponding to the RMSI
– The frequency-domain location and bandwidth of the RMSI CORESET are
indicated in the PBCH (MIB). The default bandwidth is {24,48,96} RBs.
 Procedure for UEs to determine the initial BWP
Frequency
Time
SSB
CORESET
PDSCH
Frequency offset
Initial DL BWP
The frequency offset in PRB level which is between RMSI CORESET
and SS/PBCH block is defined as the frequency difference from the
lowest PRB of RMSI to the lowest PRB of SS/PBCH block.
 Initial UL BWP definition and configuration
– Function: The PUSCH used to transmit Msg3, PUCCH used to
transmit Msg4 HARQ feedback, and PRACH resources during
initial access must be transmitted in the initial active UL BWP.
– The initial DL BWP and initial UL BWP are separately configured.
– Numerology: same as that of Msg3 (configured in RMSI).
– Frequency-domain location:
– FDD (paired spectrum), SUL: configured in RMSI
– TDD (unpaired spectrum): same as the center frequency
band of the initial DL BWP
– Bandwidth
– Configured in RMSI and no default bandwidth option is
available.
UEs search for the SSB
to obtain the frequency-
domain location of the
SSB.
UEs demodulate the PBCH to obtain
the frequency offset and bandwidth
information of the RMSI CORESET and
determine the initial DL BWP.
UEs receive the RMSI to obtain the
frequency-domain location,
bandwidth, and numerology
information of the initial UL BWP.

29. 29 Huawei Confidential
Dedicated BWP Configuration
 Dedicated BWP configuration
– Sent to UEs through RRC signaling
– FDD (paired spectrum): Up to four downlink
dedicated BWPs and four uplink dedicated BWPs
can be configured.
– TDD (unpaired spectrum): A total of four
uplink/downlink BWP pairs can be configured.
– SUL: 4 uplink dedicated BWPs
– The smallest unit is one PRB. The dedicated
BWP is equal to or smaller than the maximum
bandwidth supported by a UE.
– Each dedicated BWP can be configured with
the following attributes through RRC signaling:
– Numerology (SCS, CP type)
– Bandwidth (a group of contiguous PRBs)
– Frequency location (start location)
– UEs can activate only one dedicated BWP at
a given time as the active BWP.
 UE Dedicated PRB Location
– Dedicated BWP locations of all UEs in a cell are based on the same
common reference point (Point A).
– UEs determine the start location of the dedicated BWP based on the
offset relative to Point A.
– Based on the dedicated BWP bandwidth, UEs obtain the end location of
the dedicated BWP.
– UEs obtain the frequency-domain location and size of the dedicated
BWP.
Cell Carrier Bandwidth
UE1 Active BWP UE2 Active BWP
Point A
UE1 Offset
UE2 Offset
• Offset: UEs can obtain the offset for each dedicated BWP from
RRC signaling.
After a UE accesses the network, the dedicated BWP is configured through RRC signaling. A maximum of four
dedicated BWPs can be configured.

30. 30 Huawei Confidential
BWP Adaptation
 BWP Adaptation
 UEs in RRC_CONNECTED mode switch between
dedicated BWPs (only one dedicated BWP can be
activated at a given time).
 BWP Adaptation is completed through switchovers and
involves the following:
– DCI
 FDD: downlink: downlink DCI, uplink: uplink DCI
 TDD: If the uplink or downlink DCI includes a
switchover indication, BWP switchovers are
performed in the uplink and downlink.
– Timer mechanism
 If the BWP inactivity timer expires, UEs switch to the
default BWP (one of the dedicated BWPs).
 Timer granularity: 1 ms for sub-6 GHz, 0.5 ms for
mmWave
 BWP Adaptation application scenarios
– The BWP bandwidth changes: e.g. switching to the
power saving state.
– BWP location movement in the frequency domain:
e.g. to increase scheduling flexibility.
– The BWP numerology changes: e.g. to allow
different services.
 RF conversion time (defined in RAN4,
sub-6 GHz)
UE BWP inactivity timer
PDCCH indicating downlink assignment
The UE switches to the default
BWP.
Relationship
Between
BWP1 and
BWP2
Intra-Band
Inter-Band
Same
Center
Frequency
Different
Center
Frequency
Time ≤ 20µs 50–200 µs ≤ 900 µs
In RRC connected mode, switching between BWPs is realized through DCI or timer mechanisms.

31. 31 Huawei Confidential
Contents
2 Time-Domain Resources
1 Numerology
3 Frequency-Domain Resources
4 Space-Domain Resources: Layer, Antenna Port, QCL

32. 32 Huawei Confidential
Codewords and Antenna Ports
 Basic concepts
– Codeword
– Upper-layer service data on which channel coding applies.
– Codewords uniquely identify data flow. By transmitting different data, MIMO
implements spatial multiplexing. The number of codewords depends on the
rank of the channel matrix.
– Layer
– The number of codewords is different from the number of transmit antennas.
Therefore, codewords need to be mapped to transmit antenna.
– Antenna port
– Logical ports used for transmission. Antenna ports do not have a one-to-one
relationship with physical antennas. They can be mapped to one or more
physical antennas.
– Antennas ports are defined based on reference signals.
Number of codewords ≤ Number of layers ≤ Number of antenna ports
 Protocol-defined number of codewords
– 1 to 4 layers: 1 codeword
– 5 to 8 layers: 2 codewords
 Protocol-defined number of layers
– DL: up to eight layers for a single user and four layers
for multiple users
– UL: up to four layers for a single user or multiple users
 Protocol-defined number of antenna ports
Channel/Signal
Maximum
Number of
Ports
Antenna Port#
UL
PUSCH with DMRS 8 or 12
{0,1,2,…,7} DMRS type 1
{0,1,2,…,11} DMRS type 2
PUCCH 1 {2000}
PRACH 1 {4000}
SRS 4 {1000,1001,1002,1003}
DL
PDSCH with DMRS 8 or 12
{1000, 1001,…,1007} DMRS type 1
{1000, 1001,…,1011} DMRS type 2
PDCCH 1 {2000}
CSI-RS 32 {3000,3001,3002,…,3031}
SSB 1 {4000}
Scrambling
Scrambling
Modulation
mapper
Modulation
mapper
Layer
mapper
Antenna
Port
mapper
RE mapper
RE mapper
OFDM signal
generation
OFDM signal
generation
Codewords Layers Antenna ports
In NR, a maximum of two codewords are supported. The maximum number of DMRS antenna ports is increased to 12.

33. Thank You
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