Asset LTE- Practical's / Demostrations
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WELCOME
INSTRUCTOR - GRAHAM WHYLEY
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LTE – Frequency Bands
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LTE – Frequency Bands
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LTE – Frequency Bands Supported Channels (non-overlapping) E-UTRA Band
* X -
Downlink Bandwidth
Channel Bandwidth (MHZ)
1.4 3 1 60 2 60 42 20 3 75 53 23 4 45 32 15 5 25 17 8 6 10 7 70 25 8 35 11 9 35 10 60 11 25 12 18 12 6 13 10 7 3 14 10 7 3 ... 33 20 34 15 35 60 42 20 36 60 42 20 37 20 38 50 39 40 40 100 UE receiver sensitivity can be relaxed Channel bandwidth too wide for the band Not supported
5 12 12 15 9 5 2 14 7 7 12 5 3* 2* 2*
10 6 6 7 4 2* 1* 7 3* 3 6 2* 1* 1* 1*
15 4 4* 5* 3 X 4 2* 4 1* X X
20 3 3* 3* 2 X 3* 1* 3 1* X X X
4 3 12 12 4 10 8 -
2 1 6 6 2 5 4 10
1 1 4 4 1 3 6
1 X 3 3 1 2 5
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LTE – Frequency Bands E-UTRA Band
Bandwidth UL (MHz)
E-ARFCN UL
Bandwidth DL (MHz)
E-ARFCN DL
Duplex Mode
1
1920-1980
13000 – 13599
2110-2170
0 – 599
FDD
2
1850-1910
13600 – 14199
1930-1990
600 - 1199
FDD
3
1710-1785
14200 – 14949
1805-1880
1200 – 1949
FDD
4
1710-1755
14950 – 15399
2110-2155
1950 – 2399
FDD
5
824-849
15400 – 15649
869-894
2400 – 2649
FDD
6
830-840
15650 – 15749
875-885
2650 – 2749
FDD
7
2500-2570
15750 – 16449
2620-2690
2750 – 3449
FDD
8
880-915
16450 – 16799
925-960
3450 – 3799
FDD
9
1749.9-1784.9
16800 – 17149
1844.9-1879.9
3800 – 4149
FDD
10
1710-1770
17150 – 17749
2110-2170
4150 – 4749
FDD
11
1427.9-1452.9
17750 – 17999
1475.9-1500.9
4750 – 4999
FDD
12
698-716
18000 – 18179
728-746
5000 – 5179
FDD
13
777-787
18180 – 18279
746-756
5180 – 5279
FDD
14
788-798
18280 – 18379
758-768
5280 – 5379
FDD
...
…
…
…
…
33
1900-1920
26000 – 26199
1900-1920
26000 – 26199
TDD
34
2010-2025
26200 – 26349
2010-2025
26200 – 26349
TDD
35
1850-1910
26350 – 26949
1850-1910
26350 – 26949
TDD
36
1930-1990
26950 – 27549
1930-1990
26950 – 27549
TDD
37
1910-1930
27550 – 27749
1910-1930
27550 – 27749
TDD
38
2570-2620
27750 – 28249
2570-2620
27750 – 28249
TDD
39
1880-1920
28250 – 28649
1880-1920
28250 – 28649
TDD
40
2300-2400
28650 – 29649
2300-2400
28650 – 29649
TDD
…
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Frame Structures
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LTE – Frame Structure
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Frame Structures-TDD
0
1
2
3
19 10 ms
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Frame Structures-TDD
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Frame Structures-FDD
10 ms
0
1
2
3
19 In half-duplex FDD operation, the UE cannot transmit and receive at the same time while there are no such restrictions in full-duplex FDD.
One Subframe = 1 mS
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Frame Structures-FDD
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LTE Carriers
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Supported Channels (non-overlapping)
LTE Carriers
E-UTRA Band
Since the appropriate LTE Frequency Band and LTE Frame Structure have been selected or defined then the Carriers can be defined.
* X -
Downlink Bandwidth
Channel Bandwidth (MHZ)
1.4 3 1 60 2 60 42 20 3 75 53 23 4 45 32 15 5 25 17 8 6 10 7 70 25 8 35 11 9 35 10 60 11 25 12 18 12 6 13 10 7 3 14 10 7 3 ... 33 20 34 15 35 60 42 20 36 60 42 20 37 20 38 50 39 40 40 100 UE receiver sensitivity can be relaxed Channel bandwidth too wide for the band Not supported
5 12 12 15 9 5 2 14 7 7 12 5 3* 2* 2*
10 6 6 7 4 2* 1* 7 3* 3 6 2* 1* 1* 1*
15 4 4* 5* 3 X 4 2* 4 1* X X
20 3 3* 3* 2 X 3* 1* 3 1* X X X
4 3 12 12 4 10 8 -
2 1 6 6 2 5 4 10
1 1 4 4 1 3 6
1 X 3 3 1 2 5
Bandwidth (MHz)
1.4
3
5
10
15
20
# of RBs
6
15
25
50
75
100
Subcarriers
72
180 300 600 900 1200 Copyright 2011 AIRCOM International
Supported Channels (non-overlapping)
LTE Carriers
E-UTRA Band
Since the appropriate LTE Frequency Band and LTE Frame Structure have been selected or defined then the Carriers can be defined.
* X -
Assign Carrier to Frequency Band
Downlink Bandwidth
Channel Bandwidth (MHZ)
1.4 3 1 60 2 60 42 20 3 75 53 23 4 45 32 15 5 25 17 8 6 10 7 70 25 8 35 11 9 35 10 60 11 25 12 18 12 6 13 10 7 3 14 10 7 3 ... 33 20 34 15 35 60 42 20 36 60 42 20 37 20 38 50 39 40 40 100 UE receiver sensitivity can be relaxed Channel bandwidth too wide for the band Not supported
5 12 12 15 9 5 2 14 7 7 12 5 3* 2* 2*
10 6 6 7 4 2* 1* 7 3* 3 6 2* 1* 1* 1*
15 4 4* 5* 3 X 4 2* 4 1* X X
20 3 3* 3* 2 X 3* 1* 3 1* X X X
4 3 12 12 4 10 8 -
2 1 6 6 2 5 4 10
1 1 4 4 1 3 6
1 X 3 3 1 2 5
Bandwidth (MHz)
1.4
3
5
10
15
20
# of RBs
6
15
25
50
75
100
Subcarriers
72
180
300
600
900
1200
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LTE – Carriers
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LTE – Carriers
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LTE – Carriers
E-UTRA Band
Bandwidth UL (MHz)
E-ARFCN UL
Bandwidth DL (MHz)
E-ARFCN DL
Duplex Mode
1
1920-1980
13000 – 13599
2110-2170
0 – 599
FDD
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LTE – Carriers
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Slot Structure and Physical Resources •ONE slot = 12 consecutive subcarriers •One slot = 0.5mS •6 or 7 OFDM symbols (depending upon cyclic perfix size), thus a single resource block is containing either 72 or 84 OFDM symbols •12x 7 = 84 OFDM symbols Copyright 2010 AIRCOM International Copyright 2011 AIRCOM International
LTE – Carriers
Bandwidth (MHz)
1.4
3
5
10
15
20
# of RBs
6
15
25
50
75
100
Subcarriers
72
180
300
600
900
1200
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LTE – Carriers
E-UTRA Band
Bandwidth UL (MHz)
...
…
33
1900-1920
34
E-ARFCN UL
Bandwidth DL (MHz)
E-ARFCN DL
Duplex Mode
…
…
…
26000 – 26199
1900-1920
26000 – 26199
TDD
2010-2025
26200 – 26349
2010-2025
26200 – 26349
TDD
35
1850-1910
26350 – 26949
1850-1910
26350 – 26949
TDD
36
1930-1990
26950 – 27549
1930-1990
26950 – 27549
TDD
37
1910-1930
27550 – 27749
1910-1930
27550 – 27749
TDD
38
2570-2620
27750 – 28249
2570-2620
27750 – 28249
TDD
39
1880-1920
28250 – 28649
1880-1920
28250 – 28649
TDD
40
2300-2400
28650 – 29649
2300-2400
28650 – 29649
TDD
…
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LTE – Carriers
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
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LTE – Carriers
R1
R0
R0
R1
R1
R1
R0
R1
R1 R0
R0
R0
R1
R0
R0
R1
Configuration of Carrier- 2 antenna
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LTE – Carriers
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REUSE 1(PRIORITISATION) 15 Mhz
Carrier 1 A1 A1 5 Mhz
A3 A2
A3 Carrier 1
Carrier 1
A2
Each sector divides the available bandwidth into prioritised (one third) and non-prioritised (two third) sections.
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REUSE 1(PRIORITISATION) 15 Mhz Carrier 1 A 1 A 1 5 Mh z
Number of Partitions = 3
A 3
A Carrier 1 3
A 2 Carrier 1
A 2
The simplest way to minimize ICI within a Frequency Reuse 1 (FR 1) scenario is by prioritisation of resources. Reuse 1 (Prioritisation) scheme prioritises certain portions of the carrier bandwidth (i.e., number of RBs) in each cell according to a set plan. The whole bandwidth is still available for transmission in all cells, but the concept is that each cell uses its prioritised RBs more often than its non-prioritised RBs, so that it minimises the interference that it may cause to other cells.
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Coordination factor The improvement of Traffic & Control SINR with the deployment of Prioritisation is dependent on the Cell Loading and on the coordination factor. coordination factor of 0 assumes no coordination at all. No dB improvement. No ICI coordination factor of 1 means perfect coordination. Recommended 0.7
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REUSE 1(PRIORITISATION)
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Soft Frequency Reuse
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Soft Frequency Reuse
Soft Frequency Reuse Scheme (Power Ratio 50%, Bandwidth Ratio 50%) Copyright 2011 AIRCOM International
Soft Frequency Reuse
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inter-cell interference control (ICIC).
The available thresholds are “RSRP” and “Relative RSRP”. RSRP is self explanatory while the latter is defined in dBs and can be expressed as the difference between the RSRPs of the serving and the strongest interfering cell
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Global Editor
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Reuse Partitioning
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Reuse Partitioning •Multiple partitions. •Two dedicated zones, one for CCUs, the other for CEUs. •Each sector can only consume CE resources from its own dedicated CE partition
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Comparison
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Site Data Base
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Bearers
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LTE – Bearers
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LTE – Bearers
The Default Uplink and Downlink LTE bearers are defined per CQI providing 15 DL bearers and 4 UL bearers.
CQI is a report sent from the UE to the eNodeB suggesting the appropriate Modulation and Coding to be used by the eNodeB Copyright 2011 AIRCOM International
Channel Quality Indicator Reporting Each default Bearers has Control & Traffic SINR requirements according to PDSCH
PUSCH
PUCCH
CQI Report
57
The UE may not have PUSCH resources
CQI
Modulation
Actual coding rate
Required SINR
1
QPSK
0.07618
-4.46
2
QPSK
0.11719
-3.75
3
QPSK
0.18848
-2.55
4
QPSK
308/1024
-1.15
5
QPSK
449/1024
1.75
6
QPSK
602/1024
3.65
7
16QAM
378/1024
5.2
8
16QAM
490/1024
6.1
9
16QAM
616/1024
7.55
10
64QAM
466/1024
10.85
11
64QAM
567/1024
11.55
12
64QAM
666/1024
12.75
13
64QAM
772/1024
14.55
14
64QAM
873/1024
18.15
15
64QAM
948/1024
19.25 Copyright 2010 AIRCOM International
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Channel Quality Indicator Reporting
15 Defaulf Bearers PDSCH
PUSCH
PUCCH
CQI Report
57
The UE may not have PUSCH resources
CQI
Modulation
Actual coding rate
Required SINR
1
QPSK
0.07618
-4.46
2
QPSK
0.11719
-3.75
3
QPSK
0.18848
-2.55
4
QPSK
308/1024
-1.15
5
QPSK
449/1024
1.75
6
QPSK
602/1024
3.65
7
16QAM
378/1024
5.2
8
16QAM
490/1024
6.1
9
16QAM
616/1024
7.55
10
64QAM
466/1024
10.85
11
64QAM
567/1024
11.55
12
64QAM
666/1024
12.75
13
64QAM
772/1024
14.55
14
64QAM
873/1024
18.15
15
64QAM
948/1024
19.25 Copyright2011 2010 AIRCOM International Copyright AIRCOM International
coding rate CQI
Modulation
Efficiency
Actual coding rate
Required SINR
1
QPSK
0.1523
0.07618
-4.46
2
QPSK
0.2344
0.11719
-3.75
3
QPSK
0.3770
0.18848
-2.55
4
QPSK
0.6016
308/1024
-1.15
5
QPSK
0.8770
449/1024
1.75
6
QPSK
1.1758
602/1024
3.65
7
16QAM
1.4766
378/1024
5.2
8
16QAM
1.9141
490/1024
6.1
9
16QAM
2.4063
616/1024
7.55
10
64QAM
2.7305
466/1024
10.85
11
64QAM
3.3223
567/1024
11.55
12
64QAM
3.9023
666/1024
12.75
13
64QAM
4.5234
772/1024
14.55
14
64QAM
5.1152
873/1024
18.15
15
64QAM
5.5547
948/1024
19.25
The coding rate indicates how many real data bits are present out of 1024 while the efficiency provides the number of information bits per modulation symbol. 602/1024 = 0.5879 QPSK = 2bits Efficiency= 2x0.5879=1.1758 data bits per symbol Copyright 2011 AIRCOM International
coding rate CQI
Modulation
Efficiency
Actual coding rate
Required SINR
1
QPSK
0.1523
0.07618
-4.46
2
QPSK
0.2344
0.11719
-3.75
3
QPSK
0.3770
0.18848
-2.55
4
QPSK
0.6016
308/1024
-1.15
5
QPSK
0.8770
449/1024
1.75
6
QPSK
1.1758
602/1024
3.65
7
16QAM
1.4766
378/1024
5.2
8
16QAM
1.9141
490/1024
6.1
9
16QAM
2.4063
616/1024
7.55
10
64QAM
2.7305
466/1024
10.85
11
64QAM
3.3223
567/1024
11.55
12
64QAM
3.9023
666/1024
12.75
13
64QAM
4.5234
772/1024
14.55
14
64QAM
5.1152
873/1024
18.15
15
64QAM
5.5547
948/1024
19.25
The coding rate indicates how many real data bits are present out of 1024 while the efficiency provides the number of information bits per modulation symbol. 602/1024 = 0.5879 QPSK = 2bits Efficiency= 2x0.5879=1.1758 data bits per symbol Copyright 2011 AIRCOM International
Coding rate
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Bearers
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Bearers
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MIMO - Multiple Input Multiple Output
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MIMO - Multiple Input Multiple Output •The propagation channel is the air interface, so that transmission antennas are handled as input to the channel, whereas receiver antennas are the output of it
MIMO Types
Number of Antennas
SISO
MISO
SIMO
MIMO
(Single Input Single Output)
(Multiple Input Single Output
(Single Input
(Multiple Input
Multiple Output)
Multiple Output)
…
…
…
…
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MIMO LTE supports downlink transmission on 1, 2 or 4 cell specific antenna ports corresponding either to 1, 2 or 4 cell-specific reference signals. On their turn each one of the RS corresponds to one antenna port.
R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0
R0
R0
R0 R0 R0 R0 R0
each antenna is uniquely identified by the position of the reference signals On their turn each one of the RS corresponds to one antenna port.
R0
R0
R0
R1
R1
R1 R1
R1 R1
R1
R0
R1 Copyright 2011 AIRCOM International
MIMO • Single antenna port; port 0 • Single User – MIMO • Transmit diversity • Open loop spatial multiplexing • Closed loop spatial multiplexing • Multi User – MIMO • Closed-loop Rank=1 pre-coding
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Tx diversity: The first and simplest downlink LTE multiple antenna scheme is : Open-loop Tx diversity. It is identical in concept to the scheme introduced in UMTS Release 99. 010100
010100
T X
R X
SU-MIMO
010100
Closed loop Tx diversity The more complex, closed loop Tx diversity techniques from UMTS have not been adopted in LTE, which instead uses the more advanced MIMO, which was not part of Release 99.
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Open-loop spatial multiplexing, no UE feedback required SU-MIMO includes : conventional techniques such as Delay (cyclic for OFDM) Diversity •In open loop in which no feedback is provided from UE configuration collapse’s to time diversity and relies on Cyclic Delay Diversity (CDD) •Creates multi-path on the received signal. Prevents signal cancellation
In case of UEs with high velocity, the quality of the feedback may deteriorate. Thus, an open loop spatial multiplexing mode is also supported which is based on predefined settings for spatial multiplexing and precoding. Copyright 2011 AIRCOM International
Closed loop Tx diversity SU-MIMO includes :Spatial Multiplexing and Precoded Spatial Multiplexing.
The UE asks for two layersRank Indicator 2 from the enodeB. UE feels it can distinguish between to different layers
PUSCH
Data and Control Multiplexing Layer Mapping Rate Matching
CQI
PMI
4 bit 16 CS
RI
Layer 1
Layer 0
Pre Coding
Code Block Segmentation Turbo Coding
Transport Blocks
Data
Physical Uplink Shared Channel (PUSCH): This physical channel found on the LTE uplink is the Uplink counterpart of PDSCH Copyright 2011 AIRCOM International
SU-MIMO-Spatial Multiplexing Spatial multiplexing allows to transmit different streams of data simultaneously on the same resource block(s) SU-MIMO 010 CW0 CW1 010
100
R X
T X 100
R0 R0 R0 R0
Two code-word streams 2x2 SU-MIMO
Depending on the pre-coding used, each code word is represented at different powers and phases on both antennas.
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
Each antenna is uniquely identified by the position of the reference signals Copyright 2011 AIRCOM International
Single user MIMO principle 4 Closed-loop spatial multiplexing Closed-loop spatial multiplexing. Here the UE reports both the RI and index of the preferred pre-coding matrix.
Spatial Multiplexing does increase throughput but this comes at an expense of higher SINR requirements as shown on the LTE bearers
Rank Indicator (RI) is the UE’s recommendation for the number of layers, i.e. streams to be used in spatial multiplexing. RI is only reported when the UE is operating in MIMO modes with spatial multiplexing Copyright 2011 AIRCOM International
Spatial Multiplexing - Rate Gain Spatial Multiplexing (SM) targets increasing users’ throughput. Depending on the number of TX and RX antennae the user experiences a Rate Gain
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Single user MIMO principle Spatial Multiplexing does increase throughput but this comes at an expense of higher SINR requirements as shown on the LTE bearers SU-MIMO
SU-MIMO Tx Diversity
This is the coverage area for SU-MIMO
Roughly speaking Diversity is used to improve coverage
+22dB Copyright 2011 AIRCOM International
Single user MIMO principle When applying diversity This is the coverage area for SU-MIMO Spatial Multiplexing (SM) targets increasing users’ throughput. Depending on the number of TX and RX antennae the user experiences a Rate Gain
SU-MIMO
What changes, are the SINR requirements for the bearers that are reduced.
SU-MIMO Tx Diversity
SM is used to increase single users’ throughput
Roughly speaking Diversity is used to improve coverage
+22dB
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Achievable DL Bearer without and with – MIMO Coverage Improvement (2TX by 2 RX)
By increasing the coverage for each bearer respectively the result will be larger areas with higher CQI bearers.
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Achievable DL Bearer without and with – MIMO Coverage Improvement (2TX by 2 RX)
So from a system perspective Diversity not only increases coverage but network throughput as well. Copyright 2011 AIRCOM International
SU-MIMO – Diversity SU-MIMO
SU-MIMO Tx Diversity
SM is used to increase single users’ throughput
+22dB
Roughly speaking Diversity is used to improve coverage
What changes, are the SINR requirements for the bearers that are divided by the corresponding table value
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How do we set this up on Asset
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Bearers-LTE Parameters
Above this threshold switch to SU-MIMO If enabled
Below this threshold switch to SU-MIMO Diversity
SU-MIMO
SU-MIMO Diversity
+22dB Copyright 2011 AIRCOM International
Multi User – MIMO
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Multi User – MIMO MU-MIMO is used to increase the cells’ throughput. This is achieved by co-scheduling terminals on the same Resource Blocks. Spatial Multiplexing does increase throughput but this comes at an expense of higher SINR requirements as shown on the LTE bearers Copyright 2011 AIRCOM International
Multi User – MIMO
Applying MUMIMO will make no obvious changes to a network unless it is overloaded.
In order for MUMIMO to be used there is a higher Traffic & Control SINR requirement defined Spatial Multiplexing does increase throughput but this comes at an expense of higher SINR requirements as shown on the LTE bearers Copyright 2011 AIRCOM International
MU-MIMO
MU-MIMO increases cell throughput and number of terminals Copyright 2011 AIRCOM International
MU-MIMO Applying MU-MIMO will make no obvious changes to a network unless it is overloaded. To demonstrate the use of MU-MIMO we will spread terminals and run the SIM in snapshot mode. The density of terminals will be high enough for many of them to fail due to insufficient capacity. Then we will enable MU-MIMO and observe how the network is now capable to serve more of the terminals
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MU-MIMO
RSRQ changes when MU-MIMO is deployed because the number of served terminals changes.
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DL Data Rate without and with MU-MIMO
large improvements close to the cell edge Copyright 2011 AIRCOM International
DL Cell Throughput without and with MUMIMO DL Cell Throughout (per cell) when MUMIMO is enabled.
effect of the eNodeB now being capable to serve a higher number of users by scheduling them on the same resources Copyright 2011 AIRCOM International
The following table indicates how a highly loaded network can accommodate extra users by deploying MU-MIMO.
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Bearers Bearers
MU-MIMO is used to increase the cells’ throughput. In order for MU-MIMO to be used there is a higher Traffic & Control SINR requirement defined Spatial Multiplexing does increase throughput but this comes at an expense of higher SINR requirements as shown on the LTE bearers Copyright 2011 AIRCOM International
How do you set MU-MIMO in Asset
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Bearers-LTE Parameters
Above this threshold switch to SU-MIMO If enabled
Below this threshold switch to SU-MIMO Diversity
SU-MIMO
SU-MIMO Diversity
+22dB Copyright 2011 AIRCOM International
Bearers-LTE Parameters
If enabled
MU-MIMO
SU-MIMO Diversity +18dB Copyright 2011 AIRCOM International
Bearers-LTE Parameters
Above this threshold switch to MU-MIMO If enabled
Below this threshold switch to SU-MIMO Diversity
SU-MIMO
MU-MIMO
+22dB
Diversity +18dB Copyright 2011 AIRCOM International
Diversity As previously mentioned Diversity’s main purpose is to increase coverage and this is done by decreasing the bearers’ SINR requirements.
The bearers with the decreased SINR requirements are easier to achieve. When applying diversity the RSRP plot and the SCH/BSC SINR plot stay the same. RSRQ stays the same as well. R0 R0 R0 R0
What changes, are the SINR requirements for the bearers that are divided by the corresponding table value.
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
R0 R0 R0 R0
each antenna is uniquely identified by the position of the reference signals
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RSRP RSRP is not affected by cell loads. This is the reason why a network is usually firstly dimensioned to provide adequate signal strength at the desired areas.
WHY?
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RSRQ RSRQ on the other hand is affected by cell loads
WHY? Especially with MUMIMO
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Comparing all different options for SUMIMO and how they affect Data Rates.
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Summary
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Terminal Types
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Terminal Types
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Terminal Types
Path Loss
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Path Loss
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Terminal Types kTB :thermal noise level , in units of dBm, in the specified bandwidth The receiver Noise Figure (NF) is a measure of the degradation of the SINR caused by components in the RF signal chain. This includes the antenna filter losses, the noise introduced by the analogue part of the receiver SINR (IN)
SINR (OUT)
Ref Sens = KTB + NF + SINR
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Link Budget- Up link-Thermal noise Bandwidt Thermal noise h (Δf) power 1 Hz
−174 dBm
10 Hz
−164 dBm
100 Hz
−154 dBm
1 kHz
−144 dBm
10 kHz
−134 dBm
100 kHz
−124 dBm
180 kHz
−121.45 dBm
One LTE resource block
360Mhz
-118.4
Two LTE resource blocks
200 kHz
−120.98 dBm
1 MHz
−114 dBm
2 MHz
−111 dBm
6 MHz
−106 dBm
20 MHz
−101 dBm
Terminal noise can be calculated as:
“K (Boltzmann constant) x T (290K) x bandwidth”.
k = Boltzman constant (1.38*10-23 Joules/Kelvin) T = Temperature in degrees Kelvin R = Resistance in ohms B = Bandwidth in Hz Copyright 2011 AIRCOM International
Terminal Types Bandwidt Thermal noise h (Δf) power 180 kHz
−121.45 dBm
One LTE resource block
Terminal noise can be calculated as: “K (Boltzmann constant) x T (290K) x bandwidth 1.38*10-23 x 290000 x 180000=0.0000 0000 000072034 Convert to dBm = 10 log 0.0000 0000 000072034 -121.45 dBm for one resource block (180kHz)
k = Boltzman constant (1.38*10-23 Joules/Kelvin) T = Temperature in degrees Kelvin R = Resistance in ohms B = Bandwidth in Hz
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Terminal Types
DLRS TX Power
Downlink Reference Signal
Reference Signal Received Quality (RSRQ) RSRQ is defined as the ratio N×RSRP / (E-UTRA carrier RSSI), where N is the number of RB’s of the E-UTRA carrier RSSI measurement bandwidth. The measurements in the numerator and denominator shall be made over the same set of resource blocks.
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Terminal Types
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Terminal Types
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Terminal Types
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Terminal Types
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Traffic Raster
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Services
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Intoduction QoS differentiation, i.e. prioritisation of different services according to their requirements becomes extremely important when the system load gets higher. The most relevant parameters of QoS classes are: •Transfer Delay • Guaranteed Bit rate: Delay sensitive QoS Classes have guaranteed bit rate requirements. .
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Intoduction Allocation and Retention Priority (ARP):
Within each QoS class there are different allocation and retention priorities. The primary purpose of ARP is to decide whether a bearer establishment / modification request can be accepted or needs to be rejected in case of resource limitations . In addition, the ARP can be used (e.g. by the eNodeB) to decide which bearer(s) to drop during exceptional resource limitations
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Intoduction Users within the same QoS class and ARP class will share the available capacity. If the number of users is simply too high, then they will suffer from bad quality. In that case it is better to block a few users to guarantee the quality of existing connections, like streaming videos.
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Services When running a simulation, ASSET first attempts to serve the GBR demands of both Real Time and Non-Real Time services, taking into account the Priority values of the different services.
Allocation and Retention Priority (ARP)
Resources are first allocated to the service with the highest priority, and then to the next highest priority service, and so on.
If resources are still available after the GBR demands have been met, then different scheduling algorithms can be employed to attempt to serve the MBR of real time services. Copyright 2011 AIRCOM International
LTE QoS
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Services
No carrier defined OR BEARER
When running a simulation, ASSET first attempts to serve the GBR demands of both Real Time and Non-Real Time services, taking into account the Priority values of the different services.
After defining the General Service Parameters one or more Carriers can be related to the Service. Since a supporting Carrier has been assigned to the Service, all UL and DL Bearers will be available for selection as the Supporting Bearers.
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Services
A Minimum Bit Rate (Min-GBR) and a Maximum Bit Rate (Max-MBR) have been specified for the service. If a terminal achieves connection to one or more of the available bearers then the eNodeB will firstly allocate enough resources to it in order to achieve the MinGBR. It will keep allocating more resources to it until the terminal either reaches the Max-MBR ceiling or until there not more resources available due to cell loading.
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LTE – Bearers
The Default Uplink and Downlink LTE bearers are defined per CQI providing 15 DL bearers and 4 UL bearers. The most preferable bearer is DL-CQI-15 and the least preferable bearer is DL-CQI-1
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Services
The Default Uplink and Downlink LTE bearers are defined per CQI providing 15 DL bearers and 4 UL bearers
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Services
The Default Uplink and Downlink LTE bearers are defined per CQI providing 15 DL bearers and 4 UL bearers
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Services
After defining the General Service Parameters one or more Carriers can be related to the Service. Since a supporting Carrier has been assigned to the Service, all UL and DL Bearers will be available for selection as the Supporting Bearers.
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Packet Scheduler
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Packet Scheduler If resources are still available after the GBR demands have been met, then different scheduling algorithms can be employed to attempt to serve the Max Bit Rate.
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Round Robin Scheduler UE 1 Data Request
UE 2 Data Request
UE 6
UE 5
UE 1 Data sent
UE 2 Data sent
UE 3 data Request
UE 4
UE 3 Data sent
UE 4 Data Request
UE3
UE 4 Data sent
UE 5 Data Request
UE 2
The aim of this scheduler is to share the available/unused resources equally among the RT terminals
UE 5 Data sent
UE 1 UE 6 Data sent
UE 6 Data Request
NodeB Buffers
NodeB Packet Scheduler
The Round Robin approach is completely random asit simply allocates the same resources to all terminals in turns. Copyright 2011 AIRCOM International
Proportional Fair If resources are still available after the GBR demands have been met:
Terminals with higher data rates get a larger share of the available resources. Each terminal gets either the resources it needs to satisfy its RT-MBR demand.
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Proportional Demand If resources are still available after the GBR demands have been met: The aim of this scheduler is to allocate the remaining unused resources to RT terminals in proportion to their additional resource demands.
Proportional Demand completely ignores RF conditions Copyright 2011 AIRCOM International
Max SINR Terminals with higher bearer rates(and consequently higher SINR) are preferred over terminals with lower bearer rates (and consequently lower SINR). This means that resources are allocated first to those terminals with better SINR/channel conditions, thereby maximising the throughput.
where S is the average received signal power, I is the average interference power, and N is the noise power.
Best RF conditions are served first.
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Max SINR Own-signal interference in LTE an occur due to : •Inter-symbol interference due to multipath power exceeding cyclic prefix length •Inter-carrier interference due to Doppler spread (large UE speed) In LTE, orthogonality is often assumed unity for simplicity: a = 1 is assumed for LTE and hence Iown = 0.
where S is the average received signal power, I is the average interference power, and N is the noise power.
Best RF conditions are served first.
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The effect of different schedulers on a fairly loaded network
Best RF conditions are served first. Copyright 2011 AIRCOM International
The effect of schedulers on a heavily loaded network
Max SINR Scheduling will maximise the network throughput as terminals with the best RF conditions are served first. Copyright 2011 AIRCOM International
PCI Planning
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PCI
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PCI
GROUP
CODE
CELL SPECIFIC FREQ SHIFT
0
0
0
0
1
0
1
1
2
0
2
2
3
1
0
3
4
1
1
4
5
1
2
5
6
2
0
0
General
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PCI
GROUP
CODE
CELL SPECIFIC FREQ SHIFT
0
0
0
0
1
0
1
1
2
0
2
2
3
1
0
3
4
1
1
4
5
1
2
5
6
2
0
0
PCI
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PCI
GROUP
CODE
CELL SPECIFIC FREQ SHIFT
0
0
0
0
1
0
1
1
2
0
2
2
3
1
0
3
4
1
1
4
5
1
2
5
6
2
0
0
General
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General
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Minmise Groups
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Minmise Codes
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LTE Network Performance- Coverage and Capacity Predictions
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Cell Loads Option 1 - Cell loads Site Database and specifically under the LTE Parameters tab in the fields of Downlink Load (as a percentage) and Mean UL Interference Level (in dB)..
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Cell Loads The second option is to create a traffic raster spreading the defined LTE Terminal Type(s) and then the cell load levels get calculated by running Simulator Snapshots. In both cases a reference terminal type has to be specified for the calculation process.
Cell load levels get calculated by running Simulator Snapshots.
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Cell Loads The second option is to create a traffic raster spreading the defined LTE Terminal Type(s) and then the cell load levels get calculated by running Simulator Snapshots. In both cases a reference terminal type has to be specified for the calculation process.
You must run a traffic raster first
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Creating a Traffic Raster
Creating a Traffic Raster This is usually done per clutter type by assigning a terminal density or a relative weight to each one of the clutters.
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Creating a Traffic Raster
Creating a Traffic Raster This is usually done per clutter type by assigning a terminal density or a relative weight to each one of the clutters.
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Traffic
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Creating a Traffic Raster
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Creating a Traffic Raster
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Creating a Traffic Raster
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LTE Simulation - Resolution The decision on what resolution should be used for the simulations is based on what propagation models are assigned to the cell antennas. • Firstly, it is suggested to use a propagation model at the resolution it has been tuned for. Copyright 2011 AIRCOM International
Resolution Secondly, it is suggested to use two propagation models. •The first one (Primary) should be calculated at high resolution (2-20 meters) and for a relatively small radius (1-3 km). • The second one (Secondary) should be calculated at relatively lower resolution (20-100 meters) and for a larger radius (330km).
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Array Setting
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Path Loss •The first one (Primary) should be calculated at high resolution (2-20 meters) and for a relatively small radius (1-3 km).
The second one (Secondary) should be calculated at relatively lower resolution (20-100 meters) and for a larger radius (3Copyright 2011 AIRCOM International 30km).
Number of covering cells The number of covering cells mainly affects the accuracy of the interference based calculations. The more cells taken into account, the more accurate the interference values are.
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Results
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Best RSRP
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Path Loss
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Simulator Results
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Simulator Results
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Simulator Results
Default Beares
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BCH/SCH SINR BCH/SCH SINR is not affected by the cell load. BCH and SCH channels are positioned in the 6 central RBs of the Band Width and effect from interference is small.
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RSRQ RSRQ on the other hand is affected by cell loads. WHY?
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Diversity When applying diversity the RSRP plot and the SCH/BSC SINR plot stay the same. RSRQ stays thesame as well. What changes, are the SINR requirements for the bearers that are divided by the corresponding table value.
SU-MIMO
SU-MIMO Diversity
+22dB
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Diversity When applying diversity the RSRP plot and the SCH/BSC SINR plot stay the same. RSRQ stays thesame as well. What changes, are the SINR requirements for the bearers.
As previously mentioned Diversity’s main purpose is to increase coverage and this is done by decreasing the bearers’ SINR requirements. By increasing the coverage for each bearer respectively the result will be larger areas with higher CQI bearers.
So from a system perspective Diversity not only increases coverage but network throughput as well.
SU-MIMO
SU-MIMO Diversity
+22dB Copyright 2011 AIRCOM International
Diversity
What changes, are the SINR requirements for the bearers that are divided by the corresponding table value. Copyright 2011 AIRCOM International
Diversity
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DL Data Rate Improvement with Spatial Multiplexing
SU-MIMO
SU-MIMO Diversity
+22dB Copyright 2011 AIRCOM International
Adaptive Switching Diversity and Spatial Multiplexing provide significant gains to the network. Both of them can be deployed at the same time in Adaptive Switching mode by eNodeBs so as to provide higher throughput to users close to the cell and extended coverage to users at cell edge.
SU-MIMO Diversity
SU-MIMO
+22dB Copyright 2011 AIRCOM International
Simulator Results
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Cell Edge Threshold
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Cell Edge Threshold (Global Editor)
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