MIMO Principle
MIMO Principle
ZTE University
Objectives
Objectives
After the c
After the c
ourse, you wi
ourse, you wi
ll:
ll:
Know the MIMO mode in LTE
Know the MIMO mode in LTE
Know the benefits of MIMO
Know the benefits of MIMO
Understand the transit mode of
Understand the transit mode of
MIMO
MIMO
Objectives
Objectives
After the c
After the c
ourse, you wi
ourse, you wi
ll:
ll:
Know the MIMO mode in LTE
Know the MIMO mode in LTE
Know the benefits of MIMO
Know the benefits of MIMO
Understand the transit mode of
Understand the transit mode of
MIMO
MIMO
Contents
Contents
LTE MIMO Introduction
LTE MIMO Introduction
Transmit Modes Theory Introduction
Transmit Modes Theory Introduction
MIMO Performance
MIMO Performance
Inputs and Outputs
Single Input Single Output
Multi Input Single Output
What is MIMO?
MIMO (Multiple Input Multiple output)
A set of techniques that rely on the use of multiple antennas at the
receiver and/or transmitter. It can be used to achieve improved system
capacity and improved coverage area.
MIMO System Capacity
多输入多输出（
MIMO
）系统
：
单输入多输出（
SIMO
）系统
：
2 2 1log (1
| | )
/ /
M i iC
h
b
s
Hz
2 2 1log (1
| | )
/ /
N i iC
h
b
s
Hz
N
* 2 2 1log [det(
)]
log (1
)
/ /
m EP M i i
C
I
HH
b
s
Hz
N
N
In MIMO system, the number of antenna is related with the system capacity.
2 2
log (1
| | )
/ /
C
h
b
s Hz
单输入单输出（
SISO
）系统 ：
MISO System
：
MIMO System
：
SIMO System
：
SISO System
：
Why select MIMO ?
MIMO increase spatial dimensions
freedom for radio resources
Through space-time processing technology, make full use of space resource, to ascend the capacity of the communication system without increasing the spectrum resources and power, improving the reliability and Spectrum
efficiency.
MIMO can get more higher channel
capacity than SISO/SIMO/MISO
Contents
LTE MIMO Introduction
Transmit Modes Theory Introduction
MIMO Performance
MIMO System Model
11 12 1 1 1 1 21 22 2 2 2 2 1 2 t t t t r r r r t N N N N N N N N N h h h x n r h h h x n r x n r h h h
MIMO Signal Model Expression
LTE Key Technology---MIMO Theory
Space multiplexing & space diversity leads to higher bit rate.
Receiver
Data stream
Encode
Encode InterleaveChannel Channel Interleave Modulator QPSK 16QAM Modulator QPSK 16QAM Detector Detector MUX Data stream v12 v21 v11 v22 Trans mitter DeMUX
SFBC + FSTD
SFBC for two antenna ports
SFBC + FSTD for four antenna ports
Application Scenario for SFBC
SFBC enhance system coverage
SFBC application scenario
Application Scenario for Closed loop SM
Notes:
Support antenna ports 2/4;
Support one codeword and two codeword;
Require RI and PMI feed back from terminal;
RANK=1 corresponds to one codeword; RANK>=2 corresponds to two
codeword;
One codeword is referred to codebook beam-forming;
Application Scenario for Beam-Forming
Low correlation antenna
Beam-Forming in LTE
Codebook based
Beam-forming
Non Codebook based
Beam-forming
Contents
LTE MIMO Introduction
Transmit Modes Theory Introduction
MIMO Performance
MIMO Simulation Results-Case 1
Cell Spectrum efficiency
Cell Edge SE (5% CDF)
eNodeB
UE
0.04 5 0.04 7 0.05 4 1T2R 0 0.4 0.8 1.0 1.4 1.8 2.2 1.34 0.04 5 0.04 7 0.05 4 1T2R 0 0.01 0.02 0.03 0.04 0.05 0.06 0.042MIMO Simulation Results-Case 2
Cell Spectrum efficiency
Cell Edge SE (5% CDF)
Rank
eNodeB
UE
0.04 5 0.04 7 0.05 4 2T2R 0 0.4 0.8 1.0 1.4 1.8 2.2 1.6763 0.04 5 0.04 7 0.05 4 2T2R 0 0.01 0.02 0.03 0.04 0.05 0.06 0.0437MIMO Simulation Results-Case 3
Cell Spectrum efficiency
Cell Edge SE (5% CDF)
0.04 5 0.04 7 0.05 4 4T2R 0 0.4 0.8 1.0 1.4 1.8 2.2 1.7488 0.04 5 0.04 7 4T2R 0 0.01 0.02 0.03 0.04 0.05 0.06 0.0495 Rank
eNodeB
UE
MIMO Simulation Results
Cell Spectrum efficiency
Cell Edge SE (5% CDF)
46dBm/Antenna Macro ISD = 500m, 2*2 MIMO 0.04 5 0.04 7 0.05 4 4T2R 0 0.4 0.8 1.0 1.4 1.8 2.2 1.748 4T2R 0 0.01 0.02 0.03 0.04 0.05 0.06 0.0495 1.6763 2T2R 1.34 1T2R 0.0437 2T2R 0.042 1T2R 25% 30% 4% 18%
Simulation Results of Different MIMO Modes
FR Average Cell Throughput （Mbps） Frequency Efficiency （Mbps/Hz） Cell Edge Data Rates （Mbps）Cell Edge Frequency Efficiency
（Mbps/Hz）
Case 1
43dBm/Antenna Macro ISD =500m,10,2*2MIMO,Rank
Adaptive,20dB, 3km/h 1 8.5631 1.5774 0.2751 0.0507
Case 2
33dBm/Antenna Macro ISD = 500m,4TxBF,Single
Stream,20dB, 3km/h 1 13.9773 2.5747 0.9195 0.1694
Case 3
33dBm/Antenna Macro ISD 500m,4TxBFprecoding,
Dual Stream,20dB, 3km/h 1 13.4308 2.4741 0.8935 0.1646
Case 1
43dBm/Antenna Macro ISD = 500m,2*2MIMO,Rank
Adaptive,20dB, 3km/h 3 21.7142 1.3333 1.0842 0.0666
Case 2
33dBm/Antenna Macro ISD = 500m,4TxBF,Single
Stream,20dB, 3km/h 3 18.6087 1.1426 1.9028 0.1168
Case 3
33dBm/Antenna Macro ISD =
500m,4TxBF,precoding,Dual
Contents
LTE MIMO Introduction
Transmit Modes Theory Introduction
MIMO Performance
6
Mode 6 Codebook BFHigh priority
High priority for two antennas, Medium priority for four antennas Medium/Low priority
Medium priority for four antennas
1
Mode 1 Single Antenna Port2
Mode 2 Transmit Diversity3
Mode 3 Open Loop SM4
5
7
Mode 4 Closed-Loop SM Mode 5 MU-MIMO
Mode 7 Non Codebook BF
High priority for non-MIMO system
High priority for two antennas, Medium priority for four antennas
MIMO Modes in LTE
6
Mode 6 Codebook BFProvide Diversity Against Fading
Improve Peak data rates Improve system Capacity
Improve cell Coverage and Suppress Interference
1
Mode 1 Single Antenna Port2
Mode 2 Transmit Diversity3
Mode 3 Open Loop SM4
5
7
Mode 4 Closed-Loop SM Mode 5 MU-MIMO
Mode 7 Non Codebook BF
Correspond to Single Antenna Port
High Mobility Environment
MIMO Modes in Downlink Physical Channel
Mode1
Mode 2
Mode3
–
Mode 7
PDSCH
PBCH
PCFICH
PDCCH
PHICH
SCH
Application Selection of MIMO Modes
Cell Edge Cell Center Urban Area High Speed Cell Edge Low Speed（Indoor ） Medium SpeedHandset Adaptation to MIMO Modes
2
Transmit Diversity3
Open-Loop SM4
5
7
Closed-Loop SM MU-MIMO Non Codebook BF6
Codebook BF Mobility Speed ChangesRank Changes
MIMO Modes Conclusion
Transmit Scheme Rank Channel Correlation Mobility EnvironmentData Rates Location in the Cell Transmit Diversity (SFBC) 1 Low correlation High/Medium Speed Lower Data Rates Cell Edge Open-Loop SM 2/4 Low correlation High/Medium Speed Medium/ Lower Cell centre/ Cell Edge Double Stream Precoding 2/4 Low correlation
Low Speed Higher Date rates
Cell Centre
MU-MIMO 2/4 Low
correlation
Low Speed Higher Date rates Cell Centre Codebook Beam-forming 1 High correlation
Low Speed Lower Date rates Cell Edge Non Codebook Beam-forming 1 High correlation
Low Speed Lower Date rates
LTE Antenna Correlation
Two antenna at eNB
Four antenna at eNB
Case 2: Low Correlation (10 )
Be suitable for above 2GHz
Ant1 Ant2
Case 3: Low Correlation(4 or 10
between two Pairs )
Ant1 Ant2
Ant3 Ant4
Case 4: High correlation (0.5 )
Ant1 Ant2 Ant3 Ant4 Case 1: Medium Correlation (4 )
