NETWORK ENGINEERING
Link Adaptation mechanisms in 5G
5GC000517 Uplink and downlink link adaptation
5GC000522 256 QAM support + internal 5GC001875 Spillover - 256QAM
5GC001077 40 MHz cell bandwidth for cmWave (subfeature G: Link Adaptation update)
5GC001075 60 MHz cel bandwidth for cmWave (subfeature G: Link Adaptation update)
5GC001127 FR2 frame structure 4-1 (subfeature B; Link adaptation 50MHz)
5GC001208 E2E frame structure with 2 GP (subfeature A)
5G19/5G19A 5GC000605 DL SU adaptive 4x4 MIMO (subfeature N,P- L2 for Open/Closed Loop 4x4 DL MIMO All Ranks)
5G19A 5GC000836 FDD lower layer support - 5-20 MHz cell bandwidth
5G19A 5GC000869 80 MHz cell bandwidth for cmWave (subfeature G: Link Adaptation update)
Network Engineering Information
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•
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Doc ID: 5af442a1331dff00127a8300
Version: 1.2
Katarzyna Rybianska
Approved
© Nokia 2019
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If you have a question go to NetEng ASK and post it there:
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Disclaimer
3
•
Please note that the NEI materials are for internal use only. If they shall be used as a source for
the customer presentation, it is mandatory to align the contents with the Product Management
and/or local sales teams at first
•
This NEI slide deck reflects the state of the feature/solution as it is at the moment of the NEI slide
deck release and is being updated up to C5 (release available) milestone.
© Nokia 2019
Nokia Internal Use
Abbreviations
ACK
ATB
BLER
CRC
CSI-RS
CQI
DC
eNB
EN-DC
EPC
EPS
gNB
HARQ
ILLA
MCS
MeNB
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© Nokia 2019
Acknowledgment
Adaptive Transmission Bandwidth
Block Error Rate
cyclic redundancy check
Channel State Information- Reference Signals
Channel Quality Indicator
Intra E-UTRA Dual Connectivity
E-UTRAN NodeB
E-UTRA NR-Dual Connectivity
Evolved Packet Core
Evolved Packet System
NR NodeB (5g Node B)
Hybrid Automatic Retransmission Request
Inner Loop Link Adaptation
Modulation and Coding Scheme
Master eNB
Nokia Internal Use
SU-MIMO
MU-MIMO
NACK
NR
NSA
OLLA
PCell
PHR
PScell
PTRS
QAM
QPSK
SINR
SCell
SCG
SgNB
Single User Multiple-Input Multiple-Output
Multi User Multiple-Input Multiple-Output
Negative Acknowledgment
New Radio
Non Standalone Architecture
Open Loop Link Adapatation
Primary Cell
Power Headroom Report
Primary Cell in Secondary Cell Group
PTRS Phase Tracking Reference Signa
Quadrature Amplitude Modulation
Quadrature Phase Shift Keying
Signal to Interference plus Noise Ratio
Secondary Cell
Secondary Cell Group
Secondary gNB. SgNB and gNB are
synonymous
Link Adaptation mechanisms for NSA mode 3X
5GC000522 256 QAM for PDSCH (< 6GHz!)
5GC000517 Uplink and Downlink link adaptation
•
Subfeature A- definition MCS/PRB combinations for QPSK,
16QAM, and 64QAM modulation scheme used by PDSCH and
PUSCH aligned with Rel. 15 3GPP. This subfeature allows to
use only fixed DL/UL MCS (no link adaptation)
•
Subfeature B*- DL /UL Inner loop and outer loop link
adaptation for rank 1 and rank 2 with definition of the
mapping tables for QPSK, 16QAM, 64QAM, and 256QAM.
Support of link adaptation in DL and UL without 256 QAM
•
•
Subfeature C*- Additional methods for the improvement of
the link adaptation e.g HARQ NACK flood. Link adaptation
support for all modulations
Subfeature D*- Support of rank 3 and rank 4 in DL
•
Subfeature E- C-plane SoC update to 3GPP v15.1
•
Subfeature F*- Support of expanded PRB allocation (273
below 6GHz & 66 PRBs above 6 GHz)
•
Subfeature G*- Support of singleTx mode in UL
•
Subfeature H- Extension of TTI tracer for LA testing
purposes
•
Subfeature A- support of a single MCS for PDSCH (MCS5), which
relates to the 256QAM modulation scheme (subfeature based on
VzW specs & commercially not available)
•
Subfeature B*- PRB/MCS combinations extended by 256QAM
related MCSes. 256 QAM is used only if dedicated MCS is
configured (O&M parameter), dedicated feature flag is set and UE is
256QAM capable
•
Subfeature C- introduction of power back-off for PDSCH when
256QAM activated within the cell, adjustment of the PDSCH, PTRS
and DMRS transmission power (3GPP Rel.15 03/2018)
•
Subfeature D- C-Plane SoC update
•
Subfeature E - UE capability handling wrt 256QAM (3GPP Rel. 15
03/2018)
•
Subfeature F*- definition of MCS/PRB combination for 256QAM in
DL for PRB allocations of 162PRB (60MHz) and 256PRB/273PRB
(100MHz) (3GPP Rel. 15 06/2018)
•
Subfeature G *- Adjustment of the transmission power in DL to
fulfill 3GPP’s EVM requirement (3GPP Rel.15 06/2018)
5GC001875 256 QAM Spillover(< 6GHz!)
Feature introduced only to test some cases which were not tested in 5G19.
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* covered by the NEI materials
Link Adaptation mechanisms for NSA mode 3X
5GC000517* Uplink and Downlink link adaptation
5G19/19A 5GC000605-N,P - DL SU adaptive 4x4 MIMO - L2
for Open/Closed Loop 4x4 DL MIMO All Ranks)
5GC000522* 256 QAM for PDSCH (< 6 GHz!)
5G19A 5GC000836-J FDD lower layer support - 5-20 MHz
cell bandwidth (< 3 GHz!)
5GC001208-A E2E frame structure with 2 GP
5GC001127-B Frame structure + HARQ bundling + link
adaptation 50MHz)
5GC001075-G 60 MHz cmWave Link Adaptation
5GC001077-G 40 MHz cell bandwidth for cmWave (40
MHz cmWave Link Adaptation)
5GC000869-G 80 MHz cell bandwidth for cmWave Link
Adaptation update (L2)
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5G19A 5GC001875- 256 QAM Spillover (internal feature)
5G19A 5GC01347- Additional DMRS configuration
5G Link Adaptation mechanisms
Table of contents
Introduction
Technical
Details
Benefits and
Gains
Configuration
Management
Performance
Aspects
Motivation and Feature
Overview
Detailed Functionality
Description
Simulation, Lab and
Field Findings
Parameters and
Parameterization
Scenarios
Counters and KPIs,
Feature Impact Analysis
and Verification
1
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5G Link Adaptation mechanisms
Introduction
Table of contents
<chapter:introduction>
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Introduction
Modulation and Coding Schemes
5gNB supports following modulations on each physical channel
PUSCH
• QPSK, 16QAM, 64QAM
PUCCH
• BPSK, QPSK
PDSCH
• QPSK, 16QAM, 64QAM, 256 QAM
(only below 6GHz)*
PDCCH
• QPSK
PBCH
(Secondary
Node 5G)
© Nokia 2019
S1-U
(UP)
• QPSK
Nokia Internal Use
4G EPC
DC UE
X2
(Dual
Connectivity)
(CP+UP)
S1-U
S1-C
Support above 6GHz planned in 5GC001038 256 QAM support-mmWv above 6GHz
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Non-Standalone Architecture (NSA)
mode 3X operation
SgNB
(CP+UP)
MeNB
(Master eNB
LTE)
CP: C-Plane
UP: U-Plane
Introduction
Supported bandwidths
FR=1 (< 6GHz)
FR=2 (> 6GHz)
50 MHz – 32 PRBs
100 MHz – 64/66 PRBs
40 MHz – 106 PRBs
50 MHz – 133 PRBs
60 MHz - 162 PRBs
80 MHz – 217 PRBs
100 MHz – 256/273 PRBs
TDD
1 subframe (1ms) = 8 slots = 112 OFDM symbols
Δf = 120kHz
1 subframe (1ms) = 2 slots = 28 OFDM symbols
Δf = 30kHz
FDD
5 MHz – 25 PRBs
10 MHz – 52 PRBs
15 MHz – 79 PRBs
20 MHz – 106 PRBs
1 subframe (1ms) = 1 slot = 14 OFDM symbols
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Δf = 240kHz
1 subframe (1ms) = 16 slots = 224 OFDM symbols
(for PSS, SSS and PBCH – SS Blocks)
Please note that all BW/PRB
combinations mentioned here
were introduced in 5G19/19A
releases
Introduction
Link Adaptation
• The Link Adaptation is the most essential radio link control
function for optimizing the air interface efficiency
Link Adaptation
RU
• Its role is to control radio link quality on :
‒
‒
‒
PDSCH – new radio physical downlink shared channel
PUSCH – new radio physical uplink shared channel
PDCCH – new radio physical downlink control channel
• Link Adaptation alghorithms work within distributed unit
(gNB-DU) and are architecture agnostic
‒
gNBDU
gNBCU
AirScale
RU
gNBDU
AirFrame
gNBCU
AirScale
Same mechanisms are used in NSA and SA modes
All the methods, which are used for controlling the radio link quality on PDSCH, PUSCH,
and PDCCH, are characterized by different functions that are individually applied for
each of the physical channels
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Introduction
UE capability retrieval NSA 3X mode
• During Initial Context Setup procedure, UE
Capability Information message is sent to MeNB
indicating the support of LTE/5G dual
connectivity
• MeNB retrieves UE capabilities and triggers SgNB
(5gNB) addition procedure
• UE capabilities are passed to 5gNB-CU within the
SgNB Addition Request message and then to
5gNB-DU with UE context setup procedure
‒ UE capabilities will indicate if UE is 256QAM capable or
not
•
Based on that info Link Adaptation algorithm will/will not
use 256QAM related MCSes for PDSCH transmissions
UE
MeNB
SgNB- CU
SgNB Addition Request
RRC Connection Reconfiguration
SgNB Addition Request Ack
UE context setup request
UE context setup response
RRC Connection Reconfiguration
Complete
SgNB Reconfiguration
Complete
Cell Detection (PSS and SSS)
System Information decoding
Random Access Procedure
In 5G18A/19/19A 256QAM modulation can be only used below 6 GHz (256QAM above 6 GHz is
planned for future releases)
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Nokia Internal Use
SgNB- DU
<feature:5GC000517>
Introduction
5G Link Adaptation Overview
PDSCH
PUSCH
MCS for PDSCH is selected
based on CQIs sent from UE via
PUCCH.
MCS for PUSCH is selected
based on SINR associated with
the UL transmission.
CQIs obtained from UE are averaged
(ILLA*) and corrected (by OLLA*) in
order to select the MCS used for the
upcoming DL scheduling of the UE.
SINR measures are averaged (ILLA*)
and corrected (by OLLA*) in order to
select the MCS used for the upcoming
UL scheduling of the UE
Separate CQI reports are evaluated
per codeword** and per carrier
Separate SINR measurements are
evaluated per codeword** and per
carrier
Similar concept as in LTE, CQI and
correction factor calculated to meet BLER
Similar concept to Fast Uplink Link
target (deltaCQI) is a basis for MCS
Adaptation in LTE
selection
* ILLA- Inner Loop Link Adaptation
OLLA - Outer Loop Link Adaptation
** so far only one codeword supported in DL &UL
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PDCCH
The aggregation level for
all UEs in the cell is
configured by O&M
parameter.
Measurements provided by the
UEs and the gNB are not taken
into account for the selection of
user-individual aggregation
levels.
So far no Link Adaptation for
PDCCH
5G Link Adaptation mechanisms
Technical Details
•
•
•
<chapter:technical_details>
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LA for PDSCH
LA for PDCCH
LA for PUSCH
Technical Details
1 2 3 4
Link Adaptation
for PDSCH
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© Nokia 2019
Link Adaptation
for PDCCH
Nokia Internal Use
Link Adaptation
for PUSCH
Additional features
impacting Link
Adaptation
Technical Details
Link Adaptation for PDSCH
The purpose is to maximize system capacity, peak data rate and coverage reliability by the
adaptation of MCS to the changing radio channel conditions
OLLA - Outer Loop Link Adaptation
•
determines the offset factor (deltaCQI) in
order to eliminate systematical errors from
the CQI reports
Downlink
PDSCH HARQ
Feedback
WB-CQI
OLLA
Target
BLER
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© Nokia 2019
ILLA - Inner Loop Link Adaptation:
•
calculates the average CQI
•
corrects the average CQI by using the delta CQI provided
by the OLLA
•
based on the corrected average CQI, ILLA selects the MCS
•
Corrected and average CQI is re-calculated whenever a
CQI report or HARQ feedback is received
OLLA
Offset
ILLA
MCS
Scheduler
Assignment
Technical Details
Outer Loop Link Adaptation (1/3)
Downlink
xPDSCH
HARQ
Feedback
WB-CQI
OLLA
OLLA
Offset
ILLA
MCS
Target
BLER
Outer Loop Link Adaptation is an algorithm to correct possible systematical bias of reported WB-CQI
- Based on input values (Target DL BLER & HARQ Feedback of the initial DL transmissions) OLLA produces OLLA
offset (DeltaCQI)
- DeltaCQI is produced per UE per codeword and per carrier
- DeltaCQI is further considered during final MCS selection in ILLA (Inner Loop Link Adaptation) block
- DeltaCQI is calculated with the HARQ feedback of initial PDSCH Transmission  (on a slot basis*)
For each carrier initial DeltaCQI value is calculated which is assigned to each UE during context setup
- Initial DeltaCQI value is calculated based on OLLA DeltaCQI samples taken from UEs which completed so called
transient phase
- Only one sample is taken from each UE connecting to the cell
- Initial DeltaCQI is equal to 0 when the carrier is setup
* please note that slot duration is different for 5G TDD (different duration below and above 6 GHz) and also for FDD
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Technical Details
Outer Loop Link Adaptation (2/3)
Downlink
xPDSCH
HARQ
Feedback
WB-CQI
OLLA
OLLA
Offset
ILLA
MCS
Target
BLER
Algorithm to produce OLLA offset (Delta CQI) is as follows:
min(𝐃𝐞𝐥𝐭𝐚𝐂𝐐𝐈 + dllaDeltaCqiStepup ; dllaDeltaCqiMax)
𝐃𝐞𝐥𝐭𝐚𝐂𝐐𝐈 = max(𝐃𝐞𝐥𝐭𝐚𝐂𝐐𝐈 − dllaDeltaCqiStepdown ; dllaDeltaCqiMin)
𝐃𝐞𝐥𝐭𝐚𝐂𝐐𝐈
dllaBlerTarget
dllaDeltaCqiStepup = dllaDeltaCqiStepdown ∙
1 − dllaBlerTarget
Not a parameter, calculated
from StepDown and BLER target
• Maximum MCS(28/27 with 256QAM) reached and ACK
is received
• Minimum MCS(0) reached and NACK is received
• HARQ feedback is for retransmission
© Nokia 2019
NRCELL:
• dllaBlerTarget
• dllaDeltaCqiMax
• dllaDeltaCqiStepdown • dllaDeltaCqiMin
O&M parameters to influence OLLA calculations
Calculations are skipped in few cases (N/A):
21
for HARQ feedback = ACK
for HARQ feedback = NACK
for HARQ feedback = N/A
Nokia Internal Use
• DTX is indicated (no power detected for PUCCH resources)
• DL scheduler selected a lower MCS than the MCS
recommended by the DL Link Adaptation and for this DL
transmission, the HARQ ACK feedback is received
Technical Details
Outer Loop Link Adaptation (3/3)
Assumptions (for 1st transmission):
• DeltaCqi = -2.7 (slot #1)
• BLER target = 0.1 (10%)
• StepDown = 0.25
Slot
#1
Calculate deltaCQI
transmission:
• DeltaCqi = -2.7
•
#3
3rd
#4
DeltaCQI
DeltaCqiMax
DeltaCqi = -2.70 + 0.03 = -2.67
transmission (NACK):
• DeltaCqi = -2.67 - 0.25 = -2.92
4th transmission (NACK):
#5
•
© Nokia 2019
DeltaCQI
DeltaCQI =
= -2.67
-2.70
DeltaCQI
=
-2.92(limited)
DeltaCQI = -3.0
DeltaCqi = -2.92 - 0.25 = -3.0
(limited by DeltaCqiMin)
And so on…
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• StepUp = 0.25 * (0.1/(1-0.1)) = 0.03
• DeltaCQImin = -3
• DeltaCQImax = 3
2nd transmission (ACK):
#2
Time
1st
Animation
Nokia Internal Use
DeltaCqiMin
Technical Details
Outer Loop Link Adaptation- initial DeltaCQI
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
ILLA
OLLA
Offset
MCS
Max
#PRBs
Target
BLER
• Initial DeltaCQI is assigned to each UE for which a context is setup
• Initial DeltaCQI is calculated by the filter which is initialized with 0 when the carrier is setup and fed
with one DeltaCQI sample taken on the completion of the UE transient phase
-
UE transient phase is completed if n HARQ transmissions are received for the UE
-
n is determined by the maximum of 50 and the number of DeltaCqiStepUp until the border dllaDeltaCqiMax (O&M
parameter) is reached starting from DeltaCQI = 0
𝐧 = max (50;
•
dllaDeltaCqiMax
)
dllaDeltaCqiStepup
Not a parameter, calculated
from StepDown and BLER target
filter for evaluating the initial DeltaCQI
𝐈𝐧𝐢𝐃𝐞𝐥𝐭𝐚𝐂𝐐𝐈 = 1 −
1
20
1
iniDeltaCQI𝑝𝑟𝑒𝑣𝑈𝐸 + ( ) DeltaCQI𝑈𝐸
20
iniDeltaCQIprev is the
average of the deltaCQI
samples captured from the
UEs, which entered the cell
before the UE for which
deltaCQI (DeltaCQIUE)
sample is taken to
IniDeltaCQI calculation
•
The parameter iniDeltaCQI is setup with the configuration of the carrier and it is maintained even if all UEs leave the
carrier
•
iniDeltaCQI reset is done with restart of the carrier
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Nokia Internal Use
Technical Details
Handling of HARQ NACK flood in DL OLLA
•
For the case that the DL radio link quality between gNB and UE becomes suddenly bad,
HARQ NACK maybe provided for each received transport block
•
All these HARQ NACK feedbacks request HARQ retransmissions with high priority in DL
scheduling and allocate resources, which can’t be assigned to UEs with initial
transmissions
•
To overcome the excessive consumption of scheduling resources by UEs with poor air
link quality, the DL OLLA indicates these UEs to the DL scheduler and requests to pause
their scheduling if :
-
•
3 consecutive HARQ NACKs of initial transmissions are received
DeltaCQI is equal to NRCELL: dllaDeltaCqiMin
The pause in DL scheduling is cleared when:
-
-
if the HARQ ACK is coming from an initial DL transmission or an HARQ retransmission in DL
(scheduled before the UE is paused and which is still ‘on air’ when the decision to pause the
UE is made)
HARQ ACK is received after single DL transmission (initial treansmission or retransmission),
which is scheduled every 100ms for paused UE to evaluate the current radio link quality
Nokia Internal information: abovementioned mechanism is activated via R&D parameter : rdActNackFloodDefense
© Nokia 2019
Nokia Internal Use
which by default is set to 0 (disabled)
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Technical Details
Overview of Inner Loop Link Adaptation
Downlink
WB-CQI
xPDSCH
HARQ
Feedback
OLLA
OLLA
Offset
ILLA
MCS
Target
BLER
Inner Loop Link Adaptation calculates average, corrected CQI based on which
optimum MCS is selected for DL transmission (PDSCH)
UE is sending WB-CQI
reports that are being
averaged by ILLA
OLLA offset application
CQI to MCS mapping
Offset received from OLLA
is added to already
averaged ILLA CQI
With CQI after OLLA
correction it is possible to
map it to corresponding
MCS
More on following slides
25
© Nokia 2019
Nokia Internal Use
More on following slides
More on following slides
MCS for Scheduler
WB-CQI averaging
Technical Details
Inner Loop Link Adaptation / CQI averaging (1/2)
Downlink
WB-CQI
xPDSCH
HARQ
Feedback
OLLA
OLLA
Offset
ILLA
Target
BLER
• WB-CQI handling:
- ILLA captures WB-CQI reports from UE (from Uplink Control Information sent on PUCCH)
- WB-CQI reports are averaged using exponential filter
- Exponential filter is compliant with following formula:
𝑨𝒗𝒆𝒓𝒂𝒈𝒆𝑪𝑸𝑰(𝒕) = 𝑚𝑖𝑛 1 −
+𝑚𝑎𝑥
1
1
,1−
∙ 𝐴𝑣𝑒𝑟𝑎𝑔𝑒𝐶𝑄𝐼(𝑡 − 1) +
𝑁𝑢𝑚𝑏𝑒𝑟𝑂𝑓𝑅𝑒𝑝𝑜𝑟𝑡𝑠
𝐹𝑖𝑙𝑡𝑒𝑟𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
1
1
,
∙ 𝐼𝑛𝑠𝑡𝐶𝑞𝑖(𝑡)
𝑁𝑢𝑚𝑏𝑒𝑟𝑂𝑓𝑅𝑒𝑝𝑜𝑟𝑡𝑠 𝐹𝑖𝑙𝑡𝑒𝑟𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
- where:
•
•
•
NumberOfReports  Number of received WB-CQI reports since start of averaging
FilterConstant*  Filter constant of the exponential filter (FilterConstant =20)
InstCQI  Instantaneous WB-CQI from latest CQI report
* For first iteration, to shorten the transient phase of AverageCQI evaluation, NumberOfReports is taken instead of FilterConstant
26
© Nokia 2019
Nokia Internal Use
MCS
Technical Details
Inner Loop Link Adaptation / CQI averaging (2/2)
CQI feedback handling
START
• The calculation of the average CQI starts
with the reception of the first WB-CQI report
and considers all WB-CQIs reports except
those, where CQI=0
-
The CQI report equal to 0 is signaled in case the
UE cannot satisfy the conditions for reporting the
CQI
• If data isn’t sent by certain time period
(=no new CQIs), exponential filter is
reinitialized with next new CQI
-
Timer after which filter is reinitialized is equal to
1000ms (CQI expiry timer)
Timer
expired?
© Nokia 2019
Nokia Internal Use
Initialize CQI
averaging filter
No
(re)start CQI
expiration timer
CQI expiry timer handling (1000ms)
Calculate and
store average CQI
(AverageCQI)
END
27
Yes
CQI averaging
Technical Details
Inner Loop Link Adaptation / OLLA correction
Downlink
• The average WB-CQI measurement may be biased by
systematical errors
xPDSCH
HARQ
Feedback
WB-CQI
OLLA
OLLA
Offset
ILLA
MCS
Target
BLER
• OLLA provides WB-CQI correction to deal with potential errors
-
OLLA offset known as deltaCQI is calculated based on PDSCH initial HARQ feedback
-
At the end deltaCQI is simply added to averaged WB-CQI
𝑪𝒐𝒓𝒓𝒆𝒄𝒕𝒆𝒅𝑪𝑸𝑰 = 𝐴𝑣𝑒𝑟𝑎𝑔𝑒𝐶𝑄𝐼 + 𝐷𝑒𝑙𝑡𝑎𝐶𝑄𝐼
• Corrected CQI value is used to select proper MCS for upcoming transmission
• MCS selection is done based on CQI to MCS mapping tables
•
Separate mapping tables are used for:
-
bands ≤6 GHz and > 6GHz
-
Number of antennas and different rank indicators & numer of DMRS symbols (valid with 5GC001347)
-
256 QAM capable UEs- gNB evaluates the reported UE capabilities in order to know which UEs can use 256QAM
•
28
In 5G18A/19/19A 256 QAM is supported only below 6 GHz, 256QAM for above 6GHz is planned in future
releases
© Nokia 2019
Nokia Internal Use
Technical Details
Inner Loop Link Adaptation
Downlink
PDSCH
HARQ
Feedback
29
© Nokia 2019
Rank 1
1,50
1,91
2,33
2,80
3,24
3,67
3,90
4,36
4,92
5,30
5,67
6,51
6,93
7,49
8,01
8,45
9,16
9,53
10,21
10,67
11,31
11,56
12,17
12,85
13,43
13,88
14,36
15,15
Rank 2
1,74
2,10
2,43
2,85
3,26
3,71
3,94
4,45
5,04
5,41
5,80
6,67
7,15
7,63
8,13
8,65
9,32
9,75
10,43
10,93
11,53
11,79
12,44
13,07
13,65
14,07
14,57
15,36
* PTRS Phase Tracking Reference Signal
High band 28 GHz with 64 QAM
Modulation MCS
QPSK
0
QPSK
1
QPSK
2
QPSK
3
QPSK
4
16QAM
5
16QAM
6
16QAM
7
16QAM
8
16QAM
9
16QAM 10
64QAM 11
64QAM 12
64QAM 13
64QAM 14
64QAM 15
64QAM 16
64QAM 17
64QAM 18
64QAM 19
256QAM 20
256QAM 21
256QAM 22
256QAM 23
256QAM 24
256QAM 25
256QAM 26
256QAM 27
(11PDSCH symbols, 10%BLER 2Tx2Rx, 1 DMRS symbol, PTRS* on)
Rank Rank
MCS 1
2
0 1,78 2,31
1 2,28 2,74
2
2,7 3,13
3
3,3 3,58
4 3,64 3,87
5 4,13 4,33
6 4,68 4,79
7 5,13 5,26
8 5,66 5,7
9 5,96 6,13
10
11 6,62 6,72
12 7,14 7,23
13 7,62 7,71
14 8,16 8,27
15 8,52 8,62
16 8,87 8,99
17
18 9,67 9,82
19 10,07 10,28
20 10,61 10,74
21 11,1 11,22
22 11,52 11,71
23 12,2 12,35
24 12,55 12,76
25 13,2 13,41
26 13,64 13,88
27 14,3 14,46
28 14,75 14,93
Low band 3.5 GHz with 256 QAM
Modulation
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
16QAM
16QAM
16QAM
16QAM
16QAM
16QAM
16QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
(11PDSCH symbols, 10%BLER 2Tx2Rx, 1 DMRS symbol, PTRS* on)
Low band 3.5 GHz with 64 QAM
Corrected,
average WBCQI can be
mapped to
MCS using
dedicated
mapping
tables
provided by
5GMax
(100 MHz,
273 PRBs
below 6GHz
and 66PRBs
for above 6
GHz)
(11PDSCH symbols, 10%BLER 2Tx2Rx, 1 DMRS symbol, PTRS* on)
Example mapping tables tables
Modulation MCS Rank 1
QPSK
0
1,59
QPSK
1
2,11
QPSK
2
2,50
QPSK
3
3,06
QPSK
4
3,42
QPSK
5
3,92
QPSK
6
4,34
QPSK
7
4,85
QPSK
8
5,28
QPSK
9
5,76
16QAM 10
16QAM 11 6,52
16QAM 12 6,95
16QAM 13 7,45
16QAM 14 7,95
16QAM 15 8,48
16QAM 16 8,87
64QAM 17
64QAM 18 9,59
64QAM 19 10,15
64QAM 20 10,61
64QAM 21 11,10
64QAM 22 11,56
64QAM 23 12,25
64QAM 24 12,70
64QAM 25 13,10
64QAM 26 13,38
64QAM 27 14,12
64QAM 28 15,10
WB-CQI
OLLA
OLLA
Offset
ILLA
MCS
Target
BLER
Rank 2
2,43
2,86
3,17
3,65
3,99
4,45
4,84
5,28
5,72
6,16
6,84
7,32
7,79
8,28
8,76
9,16
9,86
10,41
10,82
11,30
11,79
12,45
12,89
13,28
14,02
14,30
15,26
• The mapping tables related to the
64QAM MCS index table skip two
MCSes (10 and 17), which are not
used in DL link adaptation.
- These MCSes are in each case
the least MCS of the next higherorder modulation scheme.
• Since the TBS is equal or smaller for
the lowest MCS of the next higherorder modulation scheme (MCS10
and MCS17) and the top MCS of the
lower-order modulation scheme
(MCS9 and MCS16) these MCSes are
skipped.
- the lower-order MCS guaranteed
a more robust transmission
compared to the higher-order
MCS.
Technical Details
Inner Loop Link Adaptation
Downlink
PDSCH
HARQ
Feedback
30
© Nokia 2019
Rank 4
2,63
2,97
3,27
3,74
4,04
4,47
4,90
5,46
5,80
6,23
6,81
7,33
7,85
8,41
8,83
9,16
10,00
10,36
10,91
11,39
11,94
12,55
12,98
13,66
14,12
14,74
15,21
Low band 3.5 GHz with 256 QAM
Modulation MCS Rank 3
QPSK
0
2,72
QPSK
1
3,06
QPSK
2
3,36
QPSK
3
3,79
QPSK
4
4,14
QPSK
5
4,65
QPSK
6
5,03
QPSK
7
5,41
QPSK
8
5,79
QPSK
9
6,29
16QAM
10
16QAM
11
6,84
16QAM
12
7,40
16QAM
13
7,85
16QAM
14
8,31
16QAM
15
8,80
16QAM
16
9,20
64QAM
17
64QAM
18
9,88
64QAM
19
10,30
64QAM
20
10,86
64QAM
21
11,21
64QAM
22
11,84
64QAM
23
12,43
64QAM
24
12,85
64QAM
25
13,45
64QAM
26
13,91
64QAM
27
14,46
64QAM
28
15,07
(11PDSCH symbols, 10%BLER 4Tx4Rx, 1 DMRS symbol)
Low band 3.5 GHz with 64 QAM
Corrected,
average WB- CQI
can be mapped
to MCS using
dedicated
mapping tables
provided by
5GMax (100
MHz, 273 PRBs
below 6GHz)
(11PDSCH symbols, 10%BLER 4Tx4Rx, 1 DMRS symbol)
Example mapping tables tables
Modulation
QPSK
QPSK
QPSK
QPSK
QPSK
16QAM
16QAM
16QAM
16QAM
16QAM
16QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
256QAM
256QAM
256QAM
256QAM
256QAM
256QAM
256QAM
256QAM
MCS
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Rank 3
1,92
2,21
2,56
2,96
3,30
3,76
4,13
4,60
5,09
5,59
6,02
6,73
7,18
7,76
8,13
8,78
9,40
9,85
10,47
10,96
11,60
11,91
12,49
13,14
13,63
14,16
14,85
15,37
WB-CQI
OLLA
OLLA
Offset
ILLA
MCS
Target
BLER
Rank 4
1,88
2,17
2,51
2,90
3,30
3,75
3,99
4,60
5,18
5,62
5,98
6,85
7,24
7,81
8,31
8,89
9,53
9,98
10,69
11,18
11,82
12,05
12,73
13,42
13,99
14,40
14,90
15,71
• Due to code rate restrictions
defined by 3GPP TS 38.214, 5.1.3),
effective channel code rate must be
smaller or equal to 0.95 in DL
transmission, therefore some
MCSes have to be excluded by the
link adaptation when PTRS is
activated.
- PRB/MCS combinations which are
not supported due to code
rate≥0,95 are listed in excel file
Downlink
Technical Details
Inner Loop Link Adaptation- TDD deployments
PDSCH
HARQ
Feedback
• CQI to MCS Mapping tables were created for following scenarios:
FR1 (below 6GHz)
WB-CQI
OLLA
OLLA
Offset
ILLA
Target
BLER
FR2 (above 6GHz)
8 PDSCH
symbols
100 MHz, PTRS on /off, Rank 1,2,3 & 4, 64 and 256
QAM
50 and 100 MHz, PTRS on, Rank 1 & 2, 64 QAM
10 PDSCH
symbols
40,50,60,80 MHz &100 MHz PTRS on/off, Rank 1, 2,3 &
4, 64 QAM and 256 QAM
-
11 PDSCH
symbols
40,50,60,80 MHz & 100 MHz - PTRS on/off, Rank 1, 2,3
& 4, 64 QAM and 256 QAM
-
12 PDSCH
symbols
100 MHz, PTRS on/off, Rank 1,2,3&4, 64 QAM and 256
QAM
50 and 100 MHz, PTRS on, Rank 1 & 2, 64 QAM
13 PDSCH
symbols
100 MHz, PTRS on /off, Rank 1,2,3 & 4 64 and 256 QAM
50 and 100 MHz, PTRS on, Rank 1 & 2, 64 QAM
Detailed mapping tables for FR1 & FR2 available here (see Measured SINR - Post Equalizer SINR). Please note that mapping tables are Nokia confidential!
Please note that for 64QAM tables MCS10 & 17 is not used by Link Adaptation
31
© Nokia 2019
MCS
<feature:5GC000836>
Technical Details
Inner Loop Link Adaptation- FDD deployments
• 5G FDD is introduced with 5GC000836 5-20 MHz cell bandwidth functionality to be used
below 3 GHz
• Separate CQI to MCS mapping tables are determined by 5GMax, covering following
scenarios:
Below 3GHz
11 PDSCH symbols
5 (25PRBs),10 (52PRBs),15 (79PRBs), 20 MHz (106 PRBs) - Rank 1&2,
PTRS on, 64 QAM and 256 QAM
12 PDSCH symbols
5 (25PRBs),10 (52PRBs),15 (79PRBs), 20 MHz (106 PRBs) - Rank 1&2,
PTRS on, 64 QAM and 256 QAM
13 PDSCH symbols
5 (25PRBs),10 (52PRBs),15 (79PRBs), 20 MHz (106 PRBs) - Rank 1&2,
PTRS on, 64 QAM and 256 QAM
Detailed mapping tables for FDD available here (see Measured SINR - Post Equalizer SINR). Please note that mapping tables are Nokia confidential!
• General Link Adaptation mechanisms from 5G TDD are reused for FDD deployments
32
In FDD slot duration equals 1 ms, therefore LA calculations are also based on 1 ms granurality
© Nokia 2019
Nokia Internal Use
Technical Details
Inner Loop Link Adaptation / Determination of DL MCS
Downlink
PDSCH
HARQ
Feedback
• MCS is selected by ILLA if corrected,
average WB- CQI is equal or greater than
the required CQI for the given MCS
-
-
If condition is not met, the evaluation
continues with the next smaller MCS index in
the list of supported MCSes and is repeated
until condition is satisified
In case none of the supported MCS satisfied
the condition, the smallest MCS index in the
list is selected.
OLLA
Next lower MCS
Minimum MCS reached ?
No
Evaluated WB-CQI ≥
Required CQI ?
No
Yes
Use this MCS
Use default
MCS*
End of MCS selection
* Default MCS (NRCELL: dllaIniMcs) is used for the transmissions in DL until the first WB-CQI report is received by the gNB.
Furthermore, the default MCS is sent to the DL scheduler if the gNB doesn’t receive a wideband CQI report for a period specified by CQI
Timer Expiry (1000ms).
33
© Nokia 2019
Nokia Internal Use
MCS
Target
BLER
Map CQI to MCS
Yes
OLLA
Offset
ILLA
Loop through all
MCSs
starting from the
highest
• The Inner Loop Link Adaptation compares
the evaluated corrected, average WB-CQI
with the required CQI for the given MCS
starting from the highest index
WB-CQI
Downlink MCS reduction
•
•
In case the calculated Transport Block Size provides more capacity then
required by the buffered data volume, downlink scheduler will
downgrade MCS
The downgraded MCS should be selected as the smallest from supported
list of MCS’s that with allocation of all PRBs will map into a TBS that is
larger or equal to total DL data volume needed to be sent to a UE
•
If such MCS will not be found, MCS will not be downgraded
•
If MCS is downgraded, scheduler sends an indication to the DL link
adaptation to allow correct deltaCQI calculation
•
This functionality is introduced by 5GC001854 Spillover for basic TDD
scheduler for multi-UE support
1.
2.
3.
34
© Nokia 2019
Example:
UE needs 250 kb data to be scheduled
UE is in good radio conditions therefore it gets rank 2 and
MCS 26 from link adaptation
MCS will be downgraded to 21 as this will give smallest TBS
in which 250 kb data will fit
Nokia Internal Use
Exemplary DL TBS mapping table [bits]
•
•
MCS
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
64QAM modulation
273PRBs
10 PDSCH
symbols
1 layer
7680
9984
12296
16136
19464
24072
28680
33816
38936
43032
43032
48168
55304
62504
71688
77896
83976
83976
90176
98376
108552
118896
127080
139376
147576
159880
167976
176208
180376
10 PDSCH
symbols
2 layers
15376
19992
24616
32304
38936
48168
57376
67584
77896
86040
86040
96264
110632
125016
143400
155776
167976
167976
180376
196776
217128
237776
254176
278776
295176
319784
335976
352440
360488
11 PDSCH
symbols
1 layer
8448
11016
13576
17416
21504
26632
31752
36896
42016
48168
48168
53288
61480
69672
77896
86040
92200
92200
98376
108552
118896
129128
139376
151608
163976
172176
184424
192624
200808
11 PDSCH
symbols
2 layers
16896
22056
27176
34856
43032
53288
63528
73776
83976
96264
96264
106576
122976
139376
155776
172176
184424
184424
196776
217128
237776
262376
278776
303240
327888
344376
368872
385272
401640
<feature:5GC000522>
256QAM related aspects
5GC000522 256 QAM support
5G19A 5GC01347 Additional DMRS configuration
35
© Nokia 2019
Nokia Internal Use
Technical Details
256QAM basics
• 5gNB DU during UE context setup procedure is able to
determine if UE is 256 QAM capable or not
In 5G18A/19/19A 256QAM modulation
can be only used below 6 GHz
• If UE capabilities indicate support for 256QAM Link
Adaptation uses 256QAM related MCS tables assuming that:
‒ 5GC000522 256 QAM for PDSCH is activated (NRCELL:
actDl256Qam= true)
‒ UE is in good radio conditions (sufficient DL SINR)
• With 256QAM additional power backoff on PDSCH is used in
order to pass 3GPP Error Vector Magnitude (EVM)
requirements to guarantee the configured BLER rate for all
transmissions independent of the applied modulation
scheme
‒ When the allowed EVM is exceeded, worse radio conditions are
experienced, what in turn leads to the lower probability of
256QAM usage
SINR
256QAM capable UE
The higher the modulation order, the
higher SINR is required
Note: Usage of power back-off is not mandatory. No checks are done by Nokia SgNB, if recommended power back-off value is configured. Nevertheless, if
© Nokia 2019
Nokia Internal Use
no or too low power back-off value is used, customer proceeds at own risk!
36
5GC000522 256 QAM support (cmWv)
Power of PDSCH when 256QAM in use
• When the support of 256QAM for PDSCH is activated by NRCELL:actDl256Qam the power of PDSCH
is calculated as:
𝑅𝐵
𝑃𝑑𝑠𝑐ℎ𝑇𝑏𝑇𝑟𝑎𝑛𝑠𝑚𝑖𝑡𝑃𝑜𝑤𝑒𝑟 = −10𝑙𝑜𝑔 𝑁𝑆𝐶
− 𝑁𝑅𝐵 − 𝑑𝑙𝑄𝑎𝑚256𝑃𝑜𝑤𝑒𝑟𝐵𝑎𝑐𝑘𝑜𝑓𝑓𝑆𝑢𝑏6 [dBm]*
where:
-
PdschTbTransmitPower – PDSCH power
converted to relative dBFS
If 256QAM feature is activated and power backoff
parameter is configured then :
-
NRBSC is the numer of subcarriers per
resource block
•
-
NRB is the total number of PRBs over the
whole bandwidth
•
-
dlQam256PowerBackoffSub6- configurable
parameter to define the power back-off
applied for UEs supporting the 256QAM in
DL bands of below 6GHz (default 1,5 dB)
PDSCH power in the cell is reduced by the value of the
power backoff
The relative power offset of DMRS, PTRS (if activated) and
CSI-RS to the PDSCH power is still the same and don’t need
any corrections
* Note: Usage of power back-off is not mandatory. No checks are done by Nokia
SgNB, if recommended power back-off value is configured. Nevertheless, if no or
too low power back-off value is used, customer proceeds at own risk!
For more details on transmission power aspects, please see 5G Power Control materials
37
© Nokia 2019
Nokia Internal Use
Technical Details
1 2 3 4
Link Adaptation
for PDSCH
38
© Nokia 2019
Link Adaptation
for PDCCH
Nokia Internal Use
Link Adaptation
for PUSCH
Additional features
impacting Link
Adaptation
Technical Details
PDCCH dimensioning
frequency
•
•
•
•
12 subcarriers
In 5G19/5G19A release PDCCH channel is located in the first one or two symbols of all slots
except PRACH slots or pure uplink slots (in case of semi-static or tdLte frame structures)
PDCCH configuration is sent to UE in cell configuration message. There is
commonControlResourceSet IE which defines where in time and frequency UE should look for DCI
PDCCH consist of so called Enhanced Control Channel Elements (CCE)
Each CCE consists of 6 Resource-Element Groups (REG)
•
Resource-Element Group
1 REG = 1 resource block during one OFDM symbol (12 RE)
1 slot (basic scheduling unit)
PDCCH uses an aggregation of several consecutive enhanced control channel elements (CCEs),
which actually defines size of the PDCCH in frequency domain
Aggregation level for PDCCH is controlled via NRCELL:aggregationLevel parameter (default:
4CCEs)
1CCE
2CCEs
4CCEs
•
Number of CCEs
(aggregationLevel parameter)
39
© Nokia 2019
8CCEs
16CCEs
16CCEs = 96REGs,
which occupies
96PRBs
Number of ResourceElement Groups (REGs)
1
6
2
12
4
24
8
48
16
96
Nokia Internal Use
273PRBs
•
time
14 OFDM symbols
When there are two symbols
used for PDCCH first symbol
is used for DL DCI and
second symbol is for UL DCI
.
.
. .
.
. .
.
.
.
. .
.
.
. .
.
. .
.
.
Technical Details
1 2 3 4
Link Adaptation
for PDSCH
40
© Nokia 2019
Link Adaptation
for PDCCH
Nokia Internal Use
Link Adaptation
for PUSCH
Additional features
impacting Link
Adaptation
Introduction
Introduction to Link Adaptation for PUSCH
The purpose is to maximize system capacity, peak data rate and coverage reliability by the
adaptation of MCS and #PRBs to the changing radio channel conditions
OLLA - Outer Loop Link Adaptation
•
determines the offset factor (deltaSINR) in
order to eliminate systematical errors from
the WB-SINR reports
Uplink
PUSCH HARQ
Feedback
WB-SINR
OLLA
Target
BLER
41
© Nokia 2019
ILLA - Inner Loop Link Adaptation:
• calculates avarage WB-SINR taking into consideration:
‒ SINR correction for power limited Ues
‒ deltaSINR value provided by OLLA
•
based on the corrected average SINR, ILLA selects the
MCS and number of PRBs (Adaptive Transmission
Bandwidth)
OLLA
Offset
ILLA
MCS,
#PRB
Scheduler
Assignment
Technical Details
Overview of Link Adaptation for PUSCH
HANDLE UL LA
START
Overview of UL LA processing
• Following actions are taken to provide MCS and maximum
PRB allocation for UL transmission
CRC feedback
SINR
estimation
Update
OLLA OFFSET
(DeltaSINR)
Recalculate
avarage SINR
(All these actions are described with more details on next slides):
-
Calculation of OLLA offset based on CRC feedback
-
WB-SINR averaging including power limited UEs
-
Calculation of corrected, average WB-SINR
-
MCS and # PRB selection
In the whole process, two corrections are applied:
WB-SINR correction
based on PHR report if
UE is power limited
42
© Nokia 2019
WB-SINR correction of
systematical bias
based on OLLA offset
Nokia Internal Use
Calculate corrected,
average SINR
(considers also SINR scaling for power limited UEs)
MCS, #PRB SELECTION
HANDLE UL LA
END
Technical Details
Outer Loop Link Adaptation (1/2)
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
OLLA
Offset
ILLA
MCS
Max
#PRBs
Target
BLER
Outer Loop Link Adaptation is an algorithm to correct possible systematical bias of reported WB-SINR
- Based on input values (Target UL BLER & HARQ Feedback of the initial PUSCH transmission) OLLA produces OLLA
offset (DeltaSINR)
- DeltaSINR is produced per Codeword and per UE in each carrier
- DeltaSINR is further considered during final MCS selection in ILLA (Inner Loop Link Adaptation) block
- DeltaSINR is calculated with the HARQ feedback of initial PUSCH transmission  (on a slot* basis)
For each carrier initial DeltaSINR value is calculated which is assigned to each UE for which a context is setup
- Initial DeltaSINR is calculated based on OLLA DeltaSINR samples taken from UEs which completed so called transient
phase
- Only one sample is taken from each UE connecting to the cell
- Initial DeltaSINR is equal to 0 when the carrier is setup
* please note that slot duration is different for 5G TDD (different duration below and above 6 GHz) and also for FDD
43
© Nokia 2019
Nokia Internal Use
Technical Details
Outer Loop Link Adaptation (2/2)
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
ILLA
OLLA
Offset
MCS
Max
#PRBs
Target
BLER
Algorithm to produce OLLA offset (DeltaSINR) is as follows:
min(𝐃𝐞𝐥𝐭𝐚𝐒𝐈𝐍𝐑 + ullaDeltaSinrStepup ; ullaDeltaSinrMax)
𝐃𝐞𝐥𝐭𝐚𝐒𝐈𝐍𝐑 = max(𝐃𝐞𝐥𝐭𝐚𝐒𝐈𝐍𝐑 − ullaDeltaSinrStepdown ; ullaDeltaSinrMin)
𝐃𝐞𝐥𝐭𝐚𝐒𝐈𝐍𝐑
𝐮𝐥𝐥𝐚𝐃𝐞𝐥𝐭𝐚𝐒𝐢𝐧𝐫𝐒𝐭𝐞𝐩𝐮𝐩 = ullaDeltaSinrStepdown ∙
ullaBlerTarget
1 − ullaBlerTarget
Not a parameter, calculated
from StepDown and BLER target
• Maximum UL MCS is reached and CRC ACK is received
• Minimum MCS (0) reached and CRC NACK is received
• CRC feedback is belonging to HARQ retransmission
© Nokia 2019
NRCELL:
• ullaBlerTarget
• ullaDeltaSinrStepdown
• ullaDeltaSinrMax
• ullaDeltaSinrMin
O&M parameters to influence OLLA calculations
Calculations are skipped in few cases (N/A):
44
for CRC feedback = ACK
for CRC feedback = NACK
for CRC feedback = N/A
Nokia Internal Use
• DTX is indicated
• UL scheduler selected a lower MCS than the MCS
recommended by the UL Link Adaptation and for this UL
transmission, the CRC ACK feedback is received for HARQ
Technical Details
Outer Loop Link AdaptationAssumptions (for 1st transmission):
• DeltaSINR = -2.7 (for slot #1)
• BLER target = 0.1 (10%)
• StepDown = 0.25
Slot
#1
Calculate DeltaSINR
transmission:
• DeltaSINR= -2.7
•
#3
3rd
#4
DeltaSINR
DeltaSinrMax
DeltaSINR = -2.70 + 0.03 = -2.67
transmission (NACK):
• DeltaSINR = -2.67 - 0.25 = -2.92
4th transmission (NACK):
• DeltaSINR = -2.92 - 0.25 = -3.0
#5
(limited by DeltaCqiMin)
And so on…
45
• StepUp = 0.25 * (0.1/(1-0.1)) = 0.03
• DeltaSINRmin = -3
• DeltaSINRmax = 3
2nd transmission (ACK):
#2
Time
1st
Animation
© Nokia 2019
Nokia Internal Use
DeltaSINR
DeltaSINR =
= -2.67
-2.70
DeltaSINR = -3.0
-2.92(limited)
DeltaSinrMin
Technical Details
Outer Loop Link Adaptation- cell specific initial DeltaSINR
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
ILLA
OLLA
Offset
MCS
Max
#PRBs
Target
BLER
• Cell specific initial DeltaSINR is assigned to each UE for which a context is setup
• Initial DeltaSINR is calculated by the filter which is initialized with 0 when the carrier is setup and fed
with one DeltaSINR sample taken on completion of the UE’s transient phase
-
UE transient phase is completed if n CRC feedbacks are received for the UE
-
n is determined by the maximum of 50 and the number of DeltaSinrStepUp until the border dllaDeltaSinrMax
(O&M parameter) is reached starting from DeltaSinr = 0
ullaDeltaSinrMax
𝐧 = max (50;
)
ullaDeltaSinrStepup
•
Not a parameter, calculated
from StepDown and BLER target
filter for evaluating the initial DeltaSINR
𝐈𝐧𝐢𝐃𝐞𝐥𝐭𝐚𝐒𝐈𝐍𝐑 = 1 −
1
20
1
iniDeltaSINR 𝑝𝑟𝑒𝑣𝑈𝐸 + ( ) DeltaSINR UE
20
iniDeltaSINRprev is the
average of the deltaSINR
samples captured from the
UEs, which entered the cell
before the UE for which
deltaSINR (DeltaSINRUE)
sample is taken to
IniDeltaSINR calculation
•
The parameter iniDeltaSINR is setup with the configuration of the carrier and is maintained even if all UEs leave the
carrier
•
iniDeltaSINR reset is done with restart of the carrier
46
© Nokia 2019
Nokia Internal Use
Technical Details
Handling of CRC NACK flood in UL OLLA
•
For the case that the UL radio link quality between gNB and UE becomes suddenly bad,
CRC NACK maybe provided by HARQ process for each received transport block
•
All these CRC NACK feedbacks request HARQ retransmissions with high priority in UL
scheduling and allocate resources, which can’t be assigned to UEs with initial
transmissions
•
To overcome the excessive consumption of scheduling resources by UEs with poor air
link quality, the UL OLLA indicates these UEs to the UL scheduler and requests to pause
their scheduling if :
•
-
3 consecutive CRC NACK feedbacks are received
-
DeltaSINR is equal to NRCELL: ullaDeltaSinrMin
The pause in UL scheduling is cleared when:
-
-
if the CRC ACK is coming from an initial UL transmission or an HARQ retransmission in UL
(scheduled before the UE is paused and which is still ‘on air’ when the decision to pause the
UE is made)
CRC ACK is received after single UL transmission (initial treansmission or retransmission),
which is scheduled every 100ms for paused UE to evaluate the current radio link quality
Nokia
Internal
47
© Nokia
2019 information: abovementioned
Nokia Internalmechanism
Use
which by default is set to 0
is activated via R&D parameter : rdActNackFloodDefense
Technical Details
Inner Loop Link Adaptation
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
OLLA
Offset
ILLA
MCS
Max
#PRBs
Target
BLER
Inner Loop Link Adaptation combines all inputs to select optimum MCS for upcoming
UL transmission (PUSCH)
WB-SINR averaging
SINR to MCS mapping
Offset received from OLLA
is added to already
averaged ILLA SINR
With SINR after OLLA
correction it is possible to
determine UL MCS and the
maximum number of
PUSCH PRBs for the
transmission
More on following slides
48
© Nokia 2019
Nokia Internal Use
More on following slides
More on following slides
MCS, # PRBs for
Scheduler
Averaging of WB-SINR
including power limited
UEs
OLLA offset application
<feature:5GC000532>
Technical Details
Inner Loop Link Adaptation / WB-SINR averaging (1/3)
Estimated SINR from Layer 2*
- Link Adaptation uses long term rank in order to determine if
ulPmiRank1SINR or ulPmiRank2SINRSum value will be feeding WB-SINR
averaging filter
* ulPmiRank2SinrLayer1 and ulPmiRank2SinrLayer2 are provided in the dB and they need
49
to be converted into linear domain
before the sum is calculated.
Nokia Internal Use
© Nokia 2019
ulPmiRank2SINR*L2
Estimated SINR from Layer 1*
Rank 2
ulPmiRank2SINR*L1
𝒖𝒍𝑷𝒎𝒊𝑹𝒂𝒏𝒌𝟐𝑺𝒊𝒏𝒓𝑺𝒖𝒎 =
= 10 ∙ log10 ( 1 2 𝒖𝒍𝑷𝒎𝒊𝑹𝒂𝒏𝒌𝟐𝑺𝒊𝒏𝒓𝐿𝑎𝑦𝑒𝑟1 + 𝒖𝒍𝑷𝒎𝒊𝑹𝒂𝒏𝒌𝟐𝑺𝒊𝒏𝒓𝐿𝑎𝑦𝑒𝑟2 )
Rank 1
ulPmiRank1SINR
• SINR is measured from SRS by 2x2 SU MIMO feature when rank 1 is used for the
transmission
• Separate SINR measurements per layer are made from PUSCH transmissions
(DMRS) If rank 2 is used
Exception: UE with only singleTx, for which SINR from PUSCH is also taken
• SINRs from two layers are summed up SINR Sum
5GC000532 UL 2x2 SU MIMO
WB-SINR handling
- Layer 1 provides SINR measurements, which are postprocessed in order
to derrive WB-SINR used by Link Adaptation to choose the MCS
SINR Sum
Long term rank=1
Long term SINR avaraging filter
Technical Details
Inner Loop Link Adaptation / WB-SINR averaging (2/3)
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
OLLA
Offset
ILLA
MCS
Max
#PRBs
Target
BLER
• Long term averaging is based on exponential filter applied to SINRs measured by L1:
𝑨𝒗𝒈𝑺𝒊𝒏𝒓𝑼𝒍 [𝑑𝐵](𝑡) = 𝑚𝑖𝑛 1 −
+𝑚𝑎𝑥
where:
1
1
,1−
∙ 𝐴𝑣𝑔𝑆𝑖𝑛𝑟𝑈𝑙(𝑡 − 1) +
𝑁𝑢𝑚𝑏𝑒𝑟𝑂𝑓𝑆𝑖𝑛𝑟𝑅𝑒𝑝𝑜𝑟𝑡𝑠
𝐹𝑖𝑙𝑡𝑒𝑟𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡 ∗
1
1
,
∙ 𝐼𝑛𝑠𝑡𝑆𝑖𝑛𝑟(𝑡) + 𝑆𝑖𝑛𝑟𝐶𝑜𝑟𝑟𝑒𝑐𝑡𝑖𝑜𝑛(𝑡)
𝑁𝑢𝑚𝑏𝑒𝑟𝑂𝑓𝑆𝑖𝑛𝑟𝑅𝑒𝑝𝑜𝑟𝑡𝑠 𝐹𝑖𝑙𝑡𝑒𝑟𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
Related to Power
Headroom Report (PHR)
More details on next slides
Whenever the
current long-term
rank indicates a
rank change in UL
transmission reset
of the exponential
filter happens**
NumberOfMeasurements  Number of received WB-SINR reports since start of averaging (value
1 is used for first iteration, outdated WB-SINR or after rank change)
FilterConstant*  Filter constant of the exponential filter (FilterConstant =20)
InstSinr  Instantaneous WB-SINR of the UL transmission
SinrCorrection  Correction factor of the SINR measurement (see next slides)
* For first iteration, to shorten the transient phase of Average WB-SINR evaluation, NumberOfReports is taken instead of FilterConstant.
NumberOfReport is also applied for the cases when WB- SINR measurement is outdated or rank has changed.
** After a reset, if no new SINR measurement is received, but the average SINR is needed again for a MCS selection, the last
50 averaged
© Nokia 2019
SINR value shall be used. Nokia Internal Use
Technical Details
Inner Loop Link Adaptation / WB-SINR averaging (3/3)
HANDLE SINR
MEASUREMENT REPORT
START
• The calculation of the average WB-SINR starts with
the reception of the first SINR measurements and
continues with the subsequently received SINR
measures
• Whenever the UE doesn’t transmit any data in UL
for a certain period, and there is SINR measure, the
average WB-SINR becomes obsolete
• The exponential filter is reinitialized with the next
predicted WB-SINR measurement available after
the break
-
51
The time after which filter is reinitialized is equal to
1000ms (SINR expiry timer)
© Nokia 2019
Timer
expired?
Yes
Initialize SINR
averaging filter
No
(re)start SINR
expiration timer
SINR expiry timer handling (1000ms)
Update
SinrCorrection
Calculate and
store average SINR
(AvgSinrUl)
HANDLE SINR
MEASUREMENT REPORT
END
SINR averaging
Power Headrom Reporting
The Power Headroom Report (PHR) provides the serving gNB information about the difference between the nominal
UE maximum transmit power and the estimated power for UL transmission per activated Serving Cell
•
PHR is a type of MAC CE (MAC Control Element) which contains info on
the power headroom level (PH) and PCMAX used for calculation of the
preceding PH field
-
•
•
Reporting procedure is controlled by two timers phrConfig:
tPeriodicPhr and phrConfig : tProhibitPhr, and by
phrConfig:dlPathlossChg which specifies the change in measured
downlink pathloss
PHR is triggered when:
- phrConfig:tPeriodicPhr expires,
- tProhibitPhr expires and the path loss has changed more than
dlPathlossChg for at least one activated Serving Cell
-
52
PHR value is mapped based on the difference between PcMax_c PUSCHPower
activation of an SCell
set up of the PSCell
© Nokia 2019
Reported value
Measured quantity value (dB)
POWER_HEADROOM_0
POWER_HEADROOM_1
POWER_HEADROOM_2
POWER_HEADROOM_3
POWER_HEADROOM_4
POWER_HEADROOM_5

POWER_HEADROOM_57
POWER_HEADROOM_58
POWER_HEADROOM_59
POWER_HEADROOM_60
POWER_HEADROOM_61
POWER_HEADROOM_62
POWER_HEADROOM_63
-23  PH  -22
-22  PH  -21
-21  PH  -20
-20  PH  -19
-19  PH  -18
-18  PH  -17

34  PH  35
35  PH  36
36  PH  37
37  PH  38
38  PH  39
39  PH  40
PH ≥ 40
Reported value
PCMAX_C_00
PCMAX_C_01
PCMAX_C_02
…
PCMAX_C_61
PCMAX_C_62
PCMAX_C_63
Measured quantity
value
PCMAX,c < -29
-29  PCMAX,c < -28
-28  PCMAX,c < -27
…
31  PCMAX,c < 32
32  PCMAX,c < 33
33  PCMAX,c
Link Adaptation uses PHR to calculate SINR correction for each PUSCH transmission
Nokia Internal Use
Unit
dBm
dBm
dBm
…
dBm
dBm
dBm
Technical Details
Inner Loop Link Adaptation / PHR report & SINR correction
• SINR correction helps to evaluate WB-SINR measurements
independently of the UEs’ transmission power condition
-
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
OLLA
Offset
ILLA
MCS
Max
#PRBs
Target
BLER
WB-SINR measurement of power limited UE is mapped to WB-SINR measurement free of any bias coming from the lack of
the UEs’ transmission power with the usage of SINR correction
• SINR correction is calculated based on the carrier specific Power Headroom Report (PHR) reported
by UE
• PHR received from UE is scaled to a PHR corresponding to an UL transmission using all PUSCH PRBs
available for the particular system bandwidth*
-
PHRScaled remains unchanged till reception of new PHR report
Power Headroom
Report scaled to a
system bandwidth
𝑷𝑯𝑹𝑺𝒄𝒂𝒍𝒆𝒅 = 10 ∙ log10
𝑁𝑢𝑚𝑃𝑢𝑠𝑐ℎ𝑃𝑟𝑏
+ 𝑃𝐻𝑅𝑈𝐸
𝑀𝑎𝑥𝑁𝑢𝑚𝑃𝑢𝑠𝑐ℎ𝑃𝑟𝑏
NumPuschPrb  number of PUSCH PRBs corresponding to UL transmission carrying PHR
MaxNumPuschPrb  Number of PRBs available for PUSCH in the particular bandwidth system
PHRUE  Received Power Headroom Report
NumSrsPrb  Number of PRBs involved in wideband SRS configuration – the wideband SRS configuration is indicated by BSRS=0, depends on
BW specific SRS configuration (CSRS parameter)
* below 6GHz: 100MHz -> 256/273 PRBs; above 6GHz: 100MHz -> 64/66 PRBs
53
© Nokia 2019
Nokia Internal Use
Technical Details
Inner Loop Link Adaptation / PHR report & SINR correction
Uplink
PUSCH
HARQ
Feedback
WB-SINR
OLLA
OLLA
Offset
ILLA
Target
BLER
• Having PHRScaled , SINR correction factor is calculated for each received PUSCH transmission
- The number of PUSCH PRBs for the SINR under evaluation is read from the HARQ process
𝑺𝒊𝒏𝒓𝑪𝒐𝒓𝒓𝒆𝒄𝒕𝒊𝒐𝒏 = 𝑚𝑎𝑥 0, 10 ∙ log10
SinrCorrection
factor is always
equal or greater
than 0
𝑁𝑢𝑚𝑃𝑢𝑠𝑐ℎ𝑃𝑟𝑏 𝑜𝑟 𝑁𝑢𝑚𝑆𝑟𝑠𝑃𝑟𝑏 ∗
− 𝑃𝐻𝑅𝑆𝑐𝑎𝑙𝑒𝑑
𝑀𝑎𝑥𝑁𝑢𝑚𝑃𝑢𝑠𝑐ℎ𝑃𝑟𝑏
NumPuschPrb  number of PUSCH PRBs corresponding to UL transmission carrying PHR
MaxNumPuschPrb  Number of PRBs available for PUSCH in the particular bandwidth system
PHRUE  Received Power Headroom Report
NumSrsPrb  Number of PRBs involved in wideband SRS configuration – the wideband SRS configuration is
indicated by BSRS=0, depends on BW specific SRS configuration (CSRS parameter)
* If the SINR is evaluated based on the sounding reference signal (SRS) and the UE runs during
transmission of the SRS into power limitation the SINR is corrected based on the allocated SRS
resources instead of the allocated PUSCH resources
Nokia Internal Use
54
© Nokia 2019
MCS
Max
#PRBs
Technical Details
Inner Loop Link Adaptation / OLLA correction
• WB-SINR free of systematical bias – OLLA correction:
- To eliminate systematical errors from SINR measurements
OLLA correction is applied
- OLLA provides so called OLLA offset (Delta SINR) which is
simply added to already averaged WB-SINR
- Rule for calculating the Corrected Average WB-SINR is
following:
𝑪𝒐𝒓𝒓𝑨𝒗𝒈𝑺𝒊𝒏𝒓𝑼𝒍 = 𝐴𝑣𝑔𝑆𝑖𝑛𝑟𝑈𝑙 + 𝐷𝑒𝑙𝑡𝑎𝑆𝐼𝑁𝑅
Calculated based on SINR and
SinrCorrection (coming from PHR)
55
© Nokia 2019
Nokia Internal Use
OLLA SINR offset based
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
Target
BLER
ILLA
OLLA
Offset
MCS
#PRBs
Technical Details
UL MCS selection algorithm
Uplink
xPUSCH
HARQ
Feedback
WB-SINR
OLLA
OLLA
Offset
ILLA
MCS
Max
#PRBs
Target
BLER
• Before corrected, averaged SINR is used for MCS selection, corrected, average WB-SINR is rescaled
• The rescaled, corrected average SINR is calculated in two steps starting with the rescaling factor of
the PHR to reflect the UEs’ power condition related to the number of PUSCH PRBs under evaluation
• Next PhrRescaled value is added to CorrAvgSinrUl
𝑷𝑯𝑹𝑹𝒆𝒔𝒄𝒂𝒍𝒆𝒅 = 10 ∙ log10
𝑀𝑎𝑥𝑁𝑢𝑚𝑃𝑢𝑠𝑐ℎ𝑃𝑟𝑏
+ 𝑷𝑯𝑹𝑺𝒄𝒂𝒍𝒆𝒅
𝐸𝑣𝑎𝑙𝑁𝑢𝑚𝑃𝑟𝑏𝑈𝑙
𝑹𝒆𝒔𝒄𝒂𝒍𝒆𝒅𝑪𝒐𝒓𝒓𝑨𝒗𝒈𝑺𝒊𝒏𝒓𝑼𝒍 = 𝐶𝑜𝑟𝑟𝐴𝑣𝑔𝑆𝑖𝑛𝑟𝑈𝑙 + min(0, 𝑃𝐻𝑅𝑅𝑒𝑠𝑐𝑎𝑙𝑒𝑑 )
where:
PHRRescaled  PHR correction factor related
# of PRBs allocated to UE
MaxNumPuschPrb  Number of PRBs
available for PUSCH in the particular
bandwidth system
EvalNumPrbUl  number of PRBs for
PUSCH transmission under evaluation
PHRScaled  Power Headroom Report scaled to
a system bandwidth
CorrAvgSinrUl Corrected average WB-SINR
RescaledCorrectedAvgSinrUl is used by the Link Adaptation to choose proper MCS
56
© Nokia 2019
Nokia Internal Use
57
© Nokia 2019
Low band 3.5 GHz, Rank 1
Corrected,
average WBSINR is mapped
to MCS using
mapping tables,
which are taking
into
consideration:
-Bandwith
-Rank Indicator
-PRB allocation
(10 PUSCH symbols, 10%BLER 2Tx2Rx, 1 DMRS symbol, PTRS on)
Technical Details
Inner Loop Link Adaptation in UL- TDD deployments
Modulat
ion
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
QPSK
16QAM
16QAM
16QAM
16QAM
16QAM
16QAM
16QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
64QAM
MCS
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
PRB8
PRB16 PRB32 PRB64 PRB128 PRB273
-2,7
-2,9
-3,8
-4,5
-4,7
-3,6
-3,0
-1,9
-1,0
-0,1
0,7
1,7
2,6
3,4
4,7
5,5
6,4
7,4
8,4
8,9
10,2
11,3
12,2
13,0
13,9
15,1
16,3
17,2
18,3
19,0
20,7
• The mapping tables skip two MCSes (10 and 17),
which are not used in UL link adaptation.
- These MCSes are in each case the least MCS of the
next higher-order modulation scheme
• Since the TBS is equal or smaller for the lowest MCS
of the next higher-order modulation scheme
(MCS10 and MCS17) and the top MCS of the lowerorder modulation scheme (MCS9 and MCS16) these
MCSes are skipped.
- the lower-order MCS guaranteed a more robust
transmission compared to the higher-order MCS
• Due to code rate restrictions defined by 3GPP TS
38.214, 5.1.3), effective channel code rate must be
smaller or equal to 0.95 in DL transmission,
therefore some MCSes have to be excluded by the
link adaptation when PTRS is activated.
- PRB/MCS combinations which are not supported
due to code rate≥0,95 are listed in excel file
Technical Details
Inner Loop Link Adaptation UL- TDD deployments
Uplink
xPUSCH
HARQ
Feedback
• SINRto MCS Mapping tables were created for following scenarios:
FR1 (below 6GHz)
WB-SINR
OLLA
OLLA
Offset
ILLA
MCS
Max
#PRBs
Target
BLER
FR2 (above 6GHz)
10 PUSCH
symbols
40,50,60,80 and 100 MHz - PTRS on/off Rank 1&2, 64
QAM
-
11 PUSCH
symbols
40,50,60,80 and 100 MHz - PTRS on/off Rank 1&2, 64
QAM
50 and 100 MHz, PTRS on, Rank 1 & 2, 64 QAM
12 PUSCH
symbols
100 MHz - PTRS on/off Rank 1&2, 64 QAM
50 and 100 MHz, PTRS on, Rank 1 & 2, 64 QAM
Detailed mapping tables for FR1 & FR2 available here (see Measured SINR - Post Equalizer SINR). Please note that mapping tables are
Nokia confidential!
58
© Nokia 2019
Technical Details
Inner Loop Link Adaptation UL- FDD deployments
• 5G FDD is introduced with 5GC000836 5-20 MHz cell bandwidth functionality to be used below 3 GHz
• Separate SINR to MCS mapping tables are determined by 5GMax, covering following scenarios:
Below 3GHz
12 PDSCH symbols
5 (25PRBs),10 (52PRBs),15 (79PRBs),20 MHz (106 PRBs) - Rank
1&2, PTRS on/off, 64 QAM
13 PDSCH symbols
5 (25PRBs),10 (52PRBs),15 (79PRBs),20 MHz (106 PRBs) - Rank
1&2, PTRS on/off 64 QAM
Detailed mapping tables for FDD available here (see Measured SINR - Post Equalizer SINR). Please note that mapping tables are Nokia confidential!
• General Link Adaptation mechanisms from 5G TDD are reused for FDD deployments
-
59
In FDD slot duration equals 1 ms, therefore LA calculations are also based on 1 ms granurality
© Nokia 2019
Nokia Internal Use
Technical Details
-
273 PRBs for frequency below 6 GHz and 66 PRBs above 6 GHz
• Algorithm verifies whether rescaled, corrected, avarage
WB-SINR satisfies SINR assigned to specific MCS within the
mapping table
-
-
Next lower
MCS
No
Minimum
MCS
reached ?
Yes
ILLA starts from the highest MCS
Execute
ATBNo
If rescaled, corrected, average WB-SINR is equal or greater than
the required WB-SINR of the highest available MCS, this MCS is
selected
if comparison fails, ILLA compares WB-SINR with the next smaller MCS and repeats
the process until SINR condition is satisfied
•
No
Corrected, average WB-SINR
≥ Required SINR for MCS
with full PRB allocation
Yes
Use this MCS
Loop through all MCSes
starting from the highest
• MCS selection is started with the highest possible MCS
and full PRB allocation
Rescale the SINR
(RescaledCorrAvgSinrUl)
Use default
MCS*
the first MCS index that passes the SINR comparison is selected and forwarded to the UL
scheduler
• In case of reaching minimum MCS (0) and the rescaled, corrected, average
WB-SINR is still too small compared to the required SINR for the maximum
PUSCH allocation Adaptive Transmission Bandwidth (ATB) algorithm is
started
End of MCS selection
* Default MCS (NRCELL: ullaIniMcs) is used for the transmissions in UL starting at the time the UE is instantiated until a short delay after finalization of the Random Access
60
© Nokia .2019
Procedure.
Furthermore, the default MCS isNokia
sentInternal
to the Use
UL scheduler if the LA doesn’t receive a wideband SINR report for a period specified by SINR Timer Expiry
(1000ms). If the default MCS is MCS0 then 14 PRBs are used for the Rank1 initial transmissions (PR447753)
Technical Details
ATB algorithm (1/4)- TDD
-
After rescaling the corrected average WB-SINR for the PRB allocation
under evaluation, ATB compares RescaledCorrAvgSinrUl with the
required SINR
• Similar as for the MCS selection the ATB stops the comparison
if the rescaled corrected average SINR is equal or greater than
the required SINR
-
In that case ATB forwards the selected PRB allocation size to the UL
scheduler as the proposed one
WB-SINR
PUSCH
HARQ
Feedback
OLLA
© Nokia 2019
ILLA
Target
BLER
MCS
Max
#PRBs
Start ATB
Yes
Yes
EvalNumPrbUl = Min. PRB
amount?
Next lower
PRB
candidate
No
Rescale the SINR for candidate PRB
amount (RescaledCorrAvgSinrUl)
RescaledCorrAvgSinrUl ≥ Required
SINR for minimum MCS (MCS 0)
and PRB candidate ?
Yes
Use this PRB
allocation
61
OLLA
Offset
End of MCS
selection
No
Candidate PRB amounts:
TDD: 128, 64, 32,16, 8 (1TX)
• Adaptive Transmission Bandwidth (ATB) algorithm evaluates
in descending order the corrected, average WB-SINR with the
required SINR starting from the highest possible PRB allocation
• Before SINR condition is checked for the given PRB allocation,
corrected, average WB-SINR is rescaled to consider current
number of PRBs under evaluation
Uplink
Technical Details
ATB algorithm (2/4)- TDD
Uplink
PUSCH
HARQ
Feedback
WB-SINR
OLLA
OLLA
Offset
ILLA
Target
BLER
• If the SINR comparison fails the ATB continues with SINR
required by the next smaller PUSCH PRB allocation
-
• ATB works as long as the proper PRB allocation is found (SINR
requirement is passed) or the smallest possible PRB
allocation is chosen
• The minimum allocation of 8 PRBs is applied only for UEs in
single layer transmission with one physical antenna (singleTx
mode UE)
Start ATB
Yes
Yes
EvalNumPrbUl = Min. PRB
amount?
No
Rescale the SINR for candidate PRB
amount (RescaledCorrAvgSinrUl)
RescaledCorrAvgSinrUl ≥ Required
SINR for minimum MCS (MCS 0)
and PRB candidate ?
Yes
Use this PRB
allocation
62
© Nokia 2019
Nokia Internal Use
Next lower
PRB
candidate
End of MCS
selection
No
Candidate PRB amounts:
TDD: 128, 64, 32,16, 8 (1TX)
New rescaled, corrected, average SINR is calculated and it is
compared with the SINR required by minimum MCS from lower PRB
allocation
MCS
Max
#PRBs
Technical Details
ATB algorithm (3/4)-TDD
Uplink
PUSCH
HARQ
Feedback
Number of PRBs used by ATB algorithm depends on cell bandwidth
and frequency
-
• 12 PUSCH symbols
-
63
100 MHz: ATB follows the PRB sequence 273 – 128 – 64 – 32 -14* –84-3-2
© Nokia 2019
* Introduced via PR450522/PR447753
for Rank1 only
Nokia Internal Use
OLLA
Offset
ILLA
MCS
Max
#PRBs
Start ATB
Yes
Yes
EvalNumPrbUl = Min. PRB
amount?
Next lower
PRB
candidate
No
Rescale the SINR for candidate PRB
amount (RescaledCorrAvgSinrUl)
RescaledCorrAvgSinrUl ≥ Required
SINR for minimum MCS (MCS 0)
and PRB candidate ?
Yes
Use this PRB
allocation
End of MCS
selection
No
Candidate PRB amounts:
TDD: 128, 64, 32,16, 8 (1TX)
-
100 MHz: ATB follows the PRB sequence 273 – 128 – 64 -48* – 32 14* – (8 singleTx only when 11 PUSCH symbols used)
80 MHz: 217 – 128 – 64 – 48*- 32 -14* – (8 singleTx only when 11
PUSCH symbols used)
60 MHz: 162 – 128 – 64 – 48*- 32 -14* – (8 singleTx only when 11
PUSCH symbols used)
40 MHz: 106 – 64 –48*- 32 -16-14* – (8 singleTx only when 11 PUSCH
symbols used)
20 MHz: 51-16-14* – (8 singleTx only when 11 PUSCH symbols used)
OLLA
Target
BLER
FR1:
• 10 &11 PUSCH symbols
-
WB-SINR
Technical Details
ATB algorithm (4/4)-TDD
Uplink
WB-SINR
PUSCH
HARQ
Feedback
OLLA
OLLA
Offset
Target
BLER
Number of PRBs used by ATB algorithm depends on cell
bandwidth and frequency
Yes
- 50 MHz: 32 - 16-14* – (8 singleTx only when 11 &12 PUSCH
symbols used)
Yes
EvalNumPrbUl = Min. PRB
amount?
No
Rescale the SINR for candidate PRB
amount (RescaledCorrAvgSinrUl)
RescaledCorrAvgSinrUl ≥ Required
SINR for minimum MCS (MCS 0)
and PRB candidate ?
Yes
Use this PRB
allocation
* Introduced via PR450522/PR447753 for Rank1 only
Nokia Internal Use
Next lower
PRB
candidate
End of MCS
selection
No
Candidate PRB amounts:
TDD: 128, 64, 32,16, 8 (1TX)
- 100 MHz: 66 – 48*- 32 -16-14* – (8 singleTx only when 11
&12 PUSCH symbols used)
© Nokia 2019
MCS
Max
#PRBs
Start ATB
• FR2:
64
ILLA
Technical Details
ATB algorithm – FDD deployments
Uplink
PUSCH
HARQ
Feedback
• Number of PRBs used by ATB depends on system bandwidth:
-
20 MHz: ATB follows the PRB sequence 106 – 48 – 24-16-12-8-6 – 4 -3
-
15 MHz: 79 – 48 – 24-16-12-8-6 – 4 -3
-
10 MHz: 52 – 48 – 24-16-12-8-6 – 4 -3
-
5 MHz: 25 – 24 –16-12-8-6 – 4 -3
• SINR values required for abovementioned PRB portions are
available in FDD SINR to MCS mapping tables attached here
© Nokia 2019
Nokia Internal Use
ILLA
MCS
Max
#PRBs
Start ATB
Yes
Yes
EvalNumPrbUl = Min. PRB
amount?
Next lower
PRB
candidate
No
Rescale the SINR for candidate PRB
amount (RescaledCorrAvgSinrUl)
RescaledCorrAvgSinrUl ≥ Required
SINR for minimum MCS (MCS 0)
and PRB candidate ?
Yes
Use this PRB
allocation
65
OLLA
Offset
End of MCS
selection
No
Candidate PRB amounts depends on
system bandwidth
The only change is different number of PRB allocations
considered by ATB
OLLA
Target
BLER
• In FDD deployments ATB algorithm principles are the same as
for TDD
•
WB-SINR
Uplink MCS and PRB reduction
•
•
•
•
•
•
In case the calculated Transport Block Size provides more capacity then required by
the buffered data volume, downlink scheduler will downgrade MCS
The downgraded MCS should be selected as the smallest from supported list of
MCS’s that with allocation of all PRBs will map into a TBS that is larger or equal to
total UL data volume needed to be sent by a UE
If such MCS will not be found, MCS will not be downgraded
If MCS is downgraded to MCS 0 and rank1 transmission is used but TBS is still much
bigger than required, scheduler will decrease number of PRBs to the smallest
possible value so that selected TBS is larger or equal to total UL data volume
needed to be sent by a UE
If MCS is downgraded, scheduler sends an indication to the DL link adaptation to
allow correct deltaSINR calculation
This functionality is introduced by 5GC001854 Spillover for basic TDD scheduler for
multi-UE support
1.
2.
3.
4.
Example:
UE needs 2 kb data to be scheduled
UE is in good radio conditions therefore it MCS 26 from link adaptation
MCS will be downgraded to 0 but still much larger than required
Number of PRBs is decreased to value 32 this will give smallest TBS in
which 2 kb data will fit
Possible PRB combinations with MCS0 (11 PUSCH symbols)
66
# of PRBs
1 layer
© Nokia 2019
2 layers
8
240
-
16
504
984
32
984
2024
64
2024
3976
66
2088
4040
128
3976
7944
256
7944
15896
273
8448
16896
Exemplary DL TBS mapping table [bits]
•
•
MCS
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
64QAM modulation
273PRBs
10 PUSCH
symbols
1 layer
7680
9984
12296
16136
19464
24072
28680
33816
38936
43032
43032
48168
55304
62504
71688
77896
83976
83976
90176
98376
108552
118896
127080
139376
147576
159880
167976
176208
180376
10 PUSCH
symbols
2 layers
15376
19992
24616
32304
38936
48168
57376
67584
77896
86040
86040
96264
110632
125016
143400
155776
167976
167976
180376
196776
217128
237776
254176
278776
295176
319784
335976
352440
360488
11 PUSCH
symbols
1 layer
8448
11016
13576
17416
21504
26632
31752
36896
42016
48168
48168
53288
61480
69672
77896
86040
92200
92200
98376
108552
118896
129128
139376
151608
163976
172176
184424
192624
200808
11 PUSCH
symbols
2 layers
16896
22056
27176
34856
43032
53288
63528
73776
83976
96264
96264
106576
122976
139376
155776
172176
184424
184424
196776
217128
237776
262376
278776
303240
327888
344376
368872
385272
401640
Technical Details
1 2 3 4
Link Adaptation
for PDSCH
67
© Nokia 2019
Link Adaptation
for PDCCH
Nokia Internal Use
Link Adaptation
for PUSCH
Additional features
impacting Link
Adaptation
5G19A 5GC01347 Additional DMRS configuration
68
© Nokia 2019
Nokia Internal Use
<feature:5GC001347>
5GC01347 Additional DMRS configuration
• This feature introduces additional DMRS configuration for PDSCH and PUSCH to support moving(up
to 120km/h, i.e. vehicle speed) UEs.
-
It is assumed that either UE moves or UE has clock error, in both cases, frequency offset estimation and
compensation (FoE and FoC) are needed
• The additional DMRS configuration is expected to be used for both FDD & TDD configuration, for
both FR1 and FR2.
•
In case UE has capability for PTRS, then it could be also used for FoC/FoE, which means additional
DMRS configuration support is not critical anymore for such UE
-
the additional DMRS in that case is mainly provide further help for channel estimation
Frame structure: tdLTE, FR1 (special & CSI-RS slots not shown):
69
© Nokia 2019
Nokia Internal Use
Additional
DMRS Symbol
5GC01347 Additional DMRS configuration
• With additional DMRS, higher system performance is expected with the cost of signalling overhead
-
This comes from the fact that better channel estimation is in place when addtional DMRS is used especially for the
UEs under varying RF conditions
• For UEs with PTRS capability, additional DMRS can help only for varying channel environment which
can have impact on throughput
• For UEs without PTRS capability, additional DMRS could also enable frequency offset estimation
which will result in better throughput for high speed UEs
• If UE is not moving and clock error is not siginificant, the additional DMRS will reduce throughput due
to higher reference signal overhead
Additional
Frame structure: semi-static 4:1, (CSI-RS slots not shown):
Dc
Dc
Ud
Dmrs
Dc
Ud
Dd
Dmrs
Dmrs
DMRS Symbol
Dd
Dd
Ud
Dd
Dd
Ud
Dd
Dd
Ud
Dd
Dd
Ud
Dd
Dd
Ud
Dd
Dd
Ud
Dd
Dd
Ud
Dmrs
GP
Dmrs
Dd
GP
Ud
Dd
Uc
Uc
Dd
Uc
Uc
Frame structure: FDD, FR1:
70
Dc
Dc
Dmrs
Dd
Dd
Dd
Dd
Dd
Dd
Dd
Dmrs
Dd
Dd
Dd
Ud
Ud
Dmrs
Ud
Ud
Ud
Ud
Ud
Ud
Ud
Dmrs
Ud
Ud
Uc
© Nokia 2019
Nokia Internal Use
Technical Details
PDSCH mapping tables when 5GC001347 Additional DMRS configuration is ON
TDD
When feature 5GC001347 Additional DMRS configuration is activated:
FR1:
•
For both 64QAM and 256QAM MCS tables, FR1, each rank, the average WB-CQI to MCS mapping table for {X PDSCH
symbols, 2DMRS symbols} reuses the table for {X-1 PDSCH symbols, 1DMRS symbol}, except that {8 PDSCH
symbols, 2DMRS symbols} reuses the table {8PDSCH symbols, 1DMRS symbol}
FR2:
•
The mapping table for {66PRB, 11PDSCH symbols, 1DMRS symbol is reused for {66PRB, 12PDSCH symbols, 2DMRS
symbols}.
•
The mapping table for {64PRB, 11PDSCH symbols, 1DMRS symbol} is reused for { 32PRB, 12PDSCH symbols,
2DMRS symbols}
•
The mapping table for {8PDSCH symbols, 1DMRS symbol} is reused for {8/9PDSCH symbols, 2DMRS symbols}.
•
The mapping table for {12PDSCH symbols, 1DMRS symbol} is reused for {13PDSCH symbols, 2DMRS symbols}.
•
The mapping table for {10PDSCH symbols, 1DMRS symbol} is reused as for {10/11PDSCH symbols, 32/64/66PRBs,
2DMRS symbols}.
FDD
When feature 5GC001347 Additional DMRS configuration is activated:
•
71
FDD mapping tables for {X PDSCH symbols, 1DMRS symbol} are reused as for {X+1 PDSCH symbols, 2DMRS
symbols}, except that table for {11PDSCH symbols, 1DMRS symbol} is reused for {11PDSCH symbols, 2DMRS
symbols}.
© Nokia 2019
Nokia Internal Use
Technical Details
PUSCH mapping tables when 5GC001347 Additional DMRS configuration is ON
When feature 5GC001347 Additional DMRS configuration is activated:
TDD
FR1:
•
The tables for the case {11 PUSCH symbols, 1 DMRS symbol, FR1} are reused for the case {12 PUSCH symbols, 2
DMRS symbols}.
•
The tables for the case {10 PUSCH symbols, 1 DMRS symbol, FR1} are reused for the case {11 PUSCH symbols, 2
DMRS symbols}.
FR2:
•
The tables for the case {10 PUSCH symbols, 1 DMRS symbol, FR2} are resued for the case {11 PUSCH symbols, 2
DMRS symbols}.
•
The tables for the case {11 PUSCH symbols, 1 DMRS symbol, FR2} are resued for the case {12 PUSCH symbols, 2
DMRS symbol}.
FDD
When feature 5GC001347 Additional DMRS configuration is activated:
•
For FDD UL, the tables for the case PTRS off, 12 PUSCH symbols, 1 DMRS symbol are reused for the case PTRS off, 13
PUSCH symbols, 2 DMRS symbols
•
The tables for the case PTRS off, 13 PUSCH symbols, 1 DMRS symbol are reused for the case PTRS off, 14 PUSCH
symbols, 2 DMRS symbols.
72
© Nokia 2019
Nokia Internal Use
5G19A DL & UL HARQ Incremental Redundancy
73
© Nokia 2019
Nokia Internal Use
For more details on e.g. k1 & k2 variables
please see 5G Scheduler materials: TDD; FDD
Technical Details
HARQ handling
Scheduling of retransmission
DL HARQ
New transmission (Tx) or Retransmission (ReTx) need is signaled by UEs over PUCCH by
ACK (transmission was successful) or NACK, if last transmission failed and retransmission
is needed. Timing for HARQ feedback is defined by variable k1 (details shown on slide 36)
Tx ACK/NACK Tx/ReTx
New transmission (Tx) or Retransmission (ReTx) need is signaled on PDCCH [DCI: New
Data Indicator (NDI)  0 or 1]. If the value is the same as the previously transmitted one
for given HARQ process, UL retransmission is expected. In turn, toggled value indicates
new transmission request. Timing for PUSCH transmission is defined by variable k2
k2=4
k2=10
74
© Nokia 2019
Tx
UL Grant Tx/ReTx
Downlink slot
The same TBS and Rank is used as for initial
transmission
The same HARQ process is used as for initial
transmission
NDI value of that HARQ process is not toggled
The same number of PDSCH symbols is used as for
the initial transmission. If there are less PDSCH
symbols available in a slot a retransmission is blocked
In case of NACK or DTX
If the maximum number of HARQ retransmissions
has been reached:
UL HARQ
Uplink slot
•
•
•
k1=1
UL Grant Tx
•
Tx/ReTx
SSB slot
PRACH slot
Nokia Internal Use
•
•
Retransmission scheduling of related TB is stopped
HARQ process is freed
•
Scheduler will consider UE as a candidate to
retransmission in the same carrier
Otherwise:
In case of ACK
HARQ process can be freed
Incremental redundancy (IR) in HARQ
• Incremental redundancy (IR) helps to increase
successfull retransmission rate
• Whenever retransmissions is needed, it is sent with
different redundancy version which means that
retransmission does not have to be identical to the
original transmission (as in case of chase combining
(CC))
-
different redundancy versions help to limit the number
of retransmissions e.g. in case of CC, 3 transmissions are
needed whereas IR never needs more than two
transmissions
-
IR has also positive effect on BLER performance of the
retransmission -see chart, where red ReTX curves for IR
are ~10dB improved against blue CC curves
• According to PR444146, IR in DL HARQ is available
already in 5G19 release, whereas IR for UL HARQ
seems to be supported with 5G19A
Source: 5GMax Link Level simulations
75
© Nokia
2019
Nokia
Internal
Use via R&D flags rdHARQDisableIncrRedundancyDl/Ul set to false
Nokia
internal
info: please note that DL & UL
IR is
activated
5G Link Adaptation mechanisms
Benefits and Gains
Table of contents
<chapter:benefits_and_gains>
76
© Nokia 2019
Nokia Internal Use
Benefits and Gains
Throughput - TDD
5G throughput
calculator
(click to follow the link)
• Exact throughput figures depend on the DL/UL ratio, number and bandwidth of configured CCs as
well as on the number of layer and modulation scheme
• For single UE with single, 100 MHz carrier and 1 beam and semi-static frame structure:with 2 OFDM
symbols
Additional DMRS (5GC001347)
77
UL
(273)
DL
(273)
UL
(273)
N
2x2
516,56
126,52
432,51
198,81
Y
2x2
698,54
126,52
583,43
198,81
cm
N
4x4
1033
126,52
864,91
198,81
cm
Y
4x4
1397
126,52
1167
198,81
Wave
mm
mm
N
cm
4:1
7:3
256QAM
cm
MIMO
DL
DL
(66)
UL
(66)
DL
(66)
UL
(66)
N
2x2
537,48
121,29
453,99
189,52
4x4
1075
121,29
908,14
189,52
© Nokia 2019
PRACH config 34, SS
Burst periodicity
10ms, 10% BLER,
csiReportPeriodicity
=80 ms
Throughput
values are given in Mbps!
Customer Confidential
4:1
7:3
256QAM
DL
(273)
Wave
PRACH config 90, SS
Burst periodicity
10ms, 10% BLER,
csiRsTrackingPeriod
=80 ms
MIMO
DL
DL
(273)
UL
(273)
DL
(273)
UL
(273)
N
2x2
484,61
113,55
404,91
178,44
Y
2x2
650,24
113,55
542,58
178,44
cm
N
4x4
969,11
113,55
809,70
178,44
cm
Y
4x4
1300
113,55
1085
178,44
Wave
mm
mm
N
Wave
cm
cm
4:1
7:3
256QAM
7:3
256QAM
4:1
MIMO
DL
MIMO
DL
DL
(66)
UL
(66)
DL
(66)
UL
(66)
N
2x2
493,95
110,96
419,43
173,38
4x4
988,33
110,96
839,21
173,38
Benefits and Gains
Throughput - FDD
5G throughput
calculator
(click to follow the link)
• Exact throughput figures depend on bandwidth, number of configured CCs as well as on the
number of layer and modulation scheme. For single UE with 1 beam:
Wave
256QAM
20 MHz
MIMO
DL
cm
N
2x2
126,18 128.50
cm
Y
cm
cm
DL
UL
15 MHz
10 MHz
5 MHz
DL
UL
DL
UL
DL
UL
94,60
97,22
61,39
64,24
29,89
30,55
2x2
169,27 128,50 126,18
97,22
82,96
64,24
39,83
30,55
N
4x4
252,21 128,50 189,22
97,22
122,80
64,24
59,76
30,55
Y
4x4
338,56 128,50 252,21
97,22
166,03
64,24
79,69
30,55
Additional DMRS (5GC001347)
Wave
256QAM
78
20 MHz
MIMO
DL
cm
N
2x2
112,90 119,17
cm
Y
cm
cm
UL
10 MHz
5 MHz
DL
UL
DL
UL
DL
UL
84,64
89,35
56,43
57,98
27,39
28,23
2x2
152,75 119,17 112,90
89,35
74,68
57,98
35,67
28,23
N
4x4
225,81 119,17 169,27
89,35
112,90
57,98
54,74
28,23
Y
4x4
305,29 119,17
225,81
89,35
Customer
Confidential
149,38
57,98
71,33
28,23
© Nokia 2019
DL
15 MHz
PRACH config 12, SS Burst periodicity
10ms,
10% BLER, csiRsTrackingPeriod=off
PRACH config 12, SS Burst periodicity
10ms,
10% BLER, csiRsTrackingPeriod=off
Throughput values are given in Mbps!
5G Link Adaptation mechanisms
Configuration
Management
Table of contents
<chapter:configuration_management>
79
© Nokia 2019
Nokia Internal Use
Configuration Management
Definition of terms and rules for parameter classification*
The ‘Basic Parameters’ category contains
primary parameters which should be considered
during cell deployment and must be adjusted to
a particular scenario:
• Network Element (NE) identifiers
• Planning parameters, e.g. neighbour definitions, frequency,
scrambling codes, PCI, RA preambles
• Parameters that are the outcome from dimensioning, i.e. basic
parameters defining amount of resources
• Basic parameters activating basic functionalities, e.g. power
control, admission control, handovers
• Parameters defining operators’ strategy, e.g. traffic steering,
thresholds for power control, handovers, cell reselections, basic
parameters defining feature behaviour
The ‘Advanced Parameters’ category contains
the parameters for network optimisation and
fine tuning:
• Decent network performance should be achieved without tuning
these parameters
• Universal defaults ensuring decent network performance need
to be defined for all parameters of this category. If this is not
possible for a given parameter it must be put to the ‘Basic
Parameters’ category
• Parameters requiring detailed system knowledge and broad
experience unless rules for the ‘Basic Parameters’ category are
violated
• All parameters (even without defaults, e.g. optional structures)
related to advanced and very complex features
The ‘Obsolete parameters’ category is intended for parameters that are candidates to be removed
from the product in a future release: * - purpose: Categories of parameters have been defined to simplify network
• Parameters always used with default value
• Parameters that are not used by operators
• Parameters that are not relevant anymore
80
© Nokia 2019
Nokia Internal Use
parametrization. Parameterization effort shall be focused mainly on Basic
ones. Categorization is reflected in a ‘view’ definition in NetAct CM Editor.
Configuration Management
New parameters
Abbreviated name
Full name
Description
Range and step
Default
NRCELL: dllaIniMcs
Initial MCS for DL
transmission
This parameter defines the default MCS for DL transmissions.The
default MCS is applied as long as CQI reports are missing or when the
CQI reports are outdated.
0...28, step 1
3
NRCELL: dllaBlerTarget
BLER Target for DL
Transmission
This parameter defines the target Block Error Ratio (BLER) of initial
downlink transmissions for DL Outer Loop Link Adaptation in percent
0.01...0.99,
step 0.01
0,1
(10%)
NRCELL: dllaDeltaCqiMax
Delta CQI maximum of
DL OLLA
This parameter defines the maximum value of the CQI offset
0...15, step 0.1
3
NRCELL: dllaDeltaCqiMin
Delta CQI minimum of
DL OLLA
This parameter defines the minimum value of the CQI offset
-15...0, step 0.1
-3
NRCELL: dllaDeltaCqiStepdown
Delta CQI stepdown of
DL OLLA
This parameter defines the size of the delta CQI step down in OLLA
for a NACK.
0...1.0, step
0.001
0.25
NRCELL: aggregationLevel
Aggregation Level
This parameter selects the aggregation level in number of control
channel elements (CCEs). Specification is detailed in 3GPP 38.211
chapter 7.3.2.1
1 CCEs (1), 2
CCEs (2), 4 CCEs
(3), 8CCEs (4),
16CCEs (5)
4 CCEs
NRCELL: actDl256Qam
Activate 256QAM in DL
This parameter activates/deactivates the support of 256QAM in DL
[false, true]
false
NRCELL:dlQam256PowerBackoffSub6
PDSCH Power Back-off
for 256QAM
This parameter defines the power back-off applied for UEs
supporting the 256QAM scheme in DL bands of below 6GHz
0.0...10.0 dB,
step 0.1 dB
1.5 dB
81
© Nokia 2019
ONLINE MODIFIABLE
REQUIRES OBJECT LOCKING
REQUIRES BTS RESTART
Configuration Management
New parameters
Full name
Description
NRCELL: ullaIniMcs
Initial MCS for UL
transmission
This parameter indicates the default MCS for UL
transmissions. The default MCS is applied as long as
SINR reports are missing or when the SINR reports are
outdated.
0...28, step 1
0
NRCELL: ullaBlerTarget
BLER Target for UL
Transmission
This parameter indicates the target Block Error Ratio
(BLER) of initial uplink transmissions for UL Outer Loop
Link Adaptation in percent
0.01...0.99, step
0.01
0.1
(10%)
NRCELL: ullaDeltaSinrMax
Delta SINR maximum of
UL OLLA
This parameter indicates the maximum value of the
SINR offset
0...15, step 0.1
3
NRCELL: ullaDeltaSinrMin
Delta SINR minimum of UL
OLLA
This parameter indicates the minimum value of the
SINR offset
-15...0, step 0.1
-3.0
NRCELL: ullaDeltaSinrStepdown
Delta SINR stepdown of
UL OLLA
This parameter indicates the size of the delta SINR
step down in OLLA for a NACK.
0...1.0, step 0.001
0.25
ONLINE MODIFIABLE
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REQUIRES OBJECT LOCKING
Nokia Internal Use
REQUIRES BTS RESTART
Range and step
Defaul
t value
Abbreviated name
Configuration Management
New parameters to be removed with introduction of 5GC000517-B
Full name
Description
NRCELLGRP:actUlla
Activate uplink link
adaptation
This parameter activates/deactivates the UL Link
Adaptation (UL LA). The default MCS is applied for all
transmission in UL when the UL LA is deactivated
[false, true]
false
NRCELLGRP:actDlla
Activate downlink link
adaptation
This parameter activates/deactivates the DL Link
Adaptation (DL LA).The default MCS is applied for all
transmission in DL when the DL LA is deactivated
[false, true]
false
This parameter defines the code rate, which is next to
the maximum supported code rate for DL
transmissions.
0.80...0.99, step
0.01
0,93
The parameter defines the code rate, which is next to
the maximum supported code rate for UL
transmissions.
0.80...0.99, step
0.01
0,93
NRCELLGRP: dllaMaxCodeRate
NRCELLGRP: ullaMaxCodeRate
ONLINE MODIFIABLE
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Supported code rate in DL
Supported code rate in UL
REQUIRES OBJECT LOCKING
Nokia Internal Use
REQUIRES BTS RESTART
Range and step
Defaul
t value
Abbreviated name
Configuration Management
New parameters related to Link Adaptation
Abbreviated name
NRBTS/phrConfig: tPeriodicPhr
NRBTS/phrConfig: tProhibitPhr
ONLINE MODIFIABLE
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Default
value
Full name
Description
Range and step
Periodic PHR timer
This parameter specifies UE configuration for
sending periodic power headroom reports
10sf (0), 20sf (1), 50sf
(2), 100sf (3), 200sf
(4), 500sf (5), 1000sf
(6), infinity (7)
20sf
0sf (0), 10sf (1), 20sf
(2), 50sf (3), 100sf (4),
200sf (5), 500sf (6),
1000sf (7)
0sf
Prohibited PHR timer
REQUIRES OBJECT LOCKING
Nokia Internal Use
This parameter specifies minimum of intermediate
time between two consecutive power headroom
reports.
REQUIRES BTS RESTART
Configuration Management
New parameters introduced with 5GC001038
Abbreviated name
Full name
Description
NRCELL:dlQam256PowerBackoffAbove6
PDSCH Power
Back-off for
256QAM (mmWave)
This parameter defines the power backoff applied for UEs supporting
the 256QAM scheme in DL bands above 6GHz
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ONLINE MODIFIABLE
REQUIRES OBJECT LOCKING
REQUIRES BTS RESTART
Range and step
Default
0.0...10.0 dB,
step 0.1 dB
4.5 dB
5G Link Adaptation mechanisms
Performance
Aspects
Table of contents
<chapter:performance_aspects>
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Nokia Internal Use
5G Link Adaptation mechanisms
Counters overview
• Please find the full list of LA related counters (for the latest updates please visit NIDD):
• Overview of DL counters:
PDSCH initial transmissions with 64QAM/256QAM MCS table using MCSxx
Successful PDSCH transmissions by initial transmission with 64QAM/256QAM MCS table using MCSxx
Successful PDSCH transmissions by any transmission with 64QAM/256QAM MCS table using MCSxx
Unsuccessful PDSCH transmissions by last HARQ reTx with 64QAM/256QAM MCS table using MCSxx
PDSCH transmissions in Rank1 with 64QAM/256QAM MCS table using MCSxx
PDSCH transmissions in Rank2 with 64QAM/256QAM MCS table using MCSxx
PDSCH transmissions in Rank3 with 64QAM/256QAM MCS table using MCSxx
PDSCH transmissions in Rank4 with 64QAM/256QAM MCS table using MCSxx
Wideband CQI Histogram when UE reports related to 64QAM table - CQI Level 0…15
Wideband CQI Histogram when UE reports related to 256QAM table - CQI Level 0…15
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Nokia Internal Use
5G Link Adaptation mechanisms
Counters overview
• Overview of UL :
PUSCH initial transmissions with CP-OFDM and 64QAM MCS table using MCSxx
Successful PUSCH transmissions by initial transmission with CP-OFDM and 64QAM MCS table using MCSxx
Successful PUSCH transmissions by any transmission with CP-OFDM and 64QAM MCS table using MCSxx
Unsuccessful PUSCH transmissions by last HARQ reTx with CP-OFDM and 64QAM MCS table using MCSxx
PUSCH initial transmissions with CP-OFDM and 64QAM MCS table using MCSxx
Successful PUSCH transmissions by initial transmission with CP-OFDM and 64QAM MCS table using MCSxx
Successful PUSCH transmissions by any transmission with CP-OFDM and 64QAM MCS table using MCSxx
Unsuccessful PUSCH transmissions by last HARQ reTx with CP-OFDM and 64QAM MCS table using MCSxx
PUSCH initial transmissions with CP-OFDM and 64QAM MCS table using MCSxx
Successful PUSCH transmissions by initial transmission with CP-OFDM and 64QAM MCS table using MCSxx
PUSCH transmissions in Rank1 with CP-OFDM and 64QAM MCS table using MCSxx
PUSCH transmissions in Rank2 with CP-OFDM and 64QAM MCS table using MCSxx
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Nokia Internal Use