臺灣博碩士論文加值系統

Heterogeneous Network (HetNet) is a combination networks such as macro cell
and small cell introduced as LTE-A standard in 3GPP Release 10 to provide higher
network capacity and coverage. In multilayer network, macro cell may has much higher
transmit power than small cell, and causes small cell users suffer interference with macro
cell. The cell-edge users of small cell may use the same radio resources with macro cell
users. To cope this interference problem, We propose optimization for resource
allocation using Taguchi’s method in scheduling users to achieve higher LTE-A system
throughput. Resource allocation has an important part in influencing the communication
networks performance to reduces inter-cell interference and improves the system’s
throughput.
Machine to Machine Communication (M2M) or known as Machine Type
Communication (MTC) is a future wireless communication technology will be carried
for industry 4.0. In HetNet, we consider some networks such as small cell, macro cell,
Wi-Fi and MTC or IoT devices operate in different bands, licensed and unlicensed.
Macro cell as the primary cell, while small cell as the secondary cell. 3GPP allows some
networks coexistence in the unlicensed band using Listen Before Talk (LBT) access
mechanism. We consider FBE-based LBT to possible coexistence among LTE-LAA
users, Wi-Fi and IoT devices in our simulation. Through matlab-based simulation, we
evaluate the LTE-A system throughput performance of different frequency band and
environment, and also compare with other optimization algorithm, such as Genetic
Algorithm. As the result, Proportional Fair (PF) is an appropriate scheduler to be used
both in licensed and unlicensed than Round Robin (RR) and Blind Equal Throughput
(BET) because it achieves higher throughput than other scheduler. We also observed that
system throughput of unlicensed band is higher than licensed band.

Heterogeneous Network (HetNet) is a combination networks such as macro cell
and small cell introduced as LTE-A standard in 3GPP Release 10 to provide higher
network capacity and coverage. In multilayer network, macro cell may has much higher
transmit power than small cell, and causes small cell users suffer interference with macro
cell. The cell-edge users of small cell may use the same radio resources with macro cell
users. To cope this interference problem, We propose optimization for resource
allocation using Taguchi’s method in scheduling users to achieve higher LTE-A system
throughput. Resource allocation has an important part in influencing the communication
networks performance to reduces inter-cell interference and improves the system’s
throughput.
Machine to Machine Communication (M2M) or known as Machine Type
Communication (MTC) is a future wireless communication technology will be carried
for industry 4.0. In HetNet, we consider some networks such as small cell, macro cell,
Wi-Fi and MTC or IoT devices operate in different bands, licensed and unlicensed.
Macro cell as the primary cell, while small cell as the secondary cell. 3GPP allows some
networks coexistence in the unlicensed band using Listen Before Talk (LBT) access
mechanism. We consider FBE-based LBT to possible coexistence among LTE-LAA
users, Wi-Fi and IoT devices in our simulation. Through matlab-based simulation, we
evaluate the LTE-A system throughput performance of different frequency band and
environment, and also compare with other optimization algorithm, such as Genetic
Algorithm. As the result, Proportional Fair (PF) is an appropriate scheduler to be used
both in licensed and unlicensed than Round Robin (RR) and Blind Equal Throughput
(BET) because it achieves higher throughput than other scheduler. We also observed that
system throughput of unlicensed band is higher than licensed band.

Cover ................................................................................................................................ i
Abstract .......................................................................................................................... iv
Acknowledgement ........................................................................................................... v
Table of Contents ........................................................................................................... vi
List of Figures .............................................................................................................. viii
List of Tables ................................................................................................................... x
Chapter 1. Introduction .................................................................................................... 1
Chapter 2. Theoretical Background ................................................................................. 4
2.1 LTE-LAA (Licensed Assisted Access) ................................................................. 4
2.1.1 Carrier Aggregation ........................................................................................ 5
2.2 Inter-Network Coexistence .................................................................................... 6
2.2.1 Listen before Talk (LBT)-Based LTE-LAA Mechanism ............................... 6
2.2.2 CSMA/CA Back-off Mechanism .................................................................... 8
2.2.3 Downlink (DL) LAA Categories .................................................................... 9
2.3 Optimization Algorithm ......................................................................................... 9
2.3.1 Taguchi’s Method ........................................................................................... 9
2.3.2 Genetic Algorithm (GA) ............................................................................... 11
Chapter 3. Adopted Algorithm ...................................................................................... 22
3.1 Taguchi’s Method ................................................................................................ 22
3.2 Genetic Algorithm (GA) ...................................................................................... 25
3.2.1 Initialization and Representation .................................................................. 26
3.2.2 Evaluation ..................................................................................................... 26
3.2.3 Roulette-Wheel Selection ............................................................................. 27
3.2.4 One-Point Crossover ...................................................................................... 29
3.2.5 Order Changing Mutation ............................................................................. 29
3.2.6 Termination Criterion .................................................................................... 30
Chapter 4. Simulation Setup, Results and Discussions ................................................. 31
4.1 Propagation and Channel Models ......................................................................... 31
4.1.1 ITU UMa ....................................................................................................... 31
4.1.2 WINNER II ................................................................................................... 32
4.1.3 Cost-231 Hata ............................................................................................... 33
4.1.4 Industrial Indoor Channel ............................................................................. 34
4.2 Resource Scheduling ........................................................................................... 34
4.2.1 Round Robin (RR) ........................................................................................ 35
4.2.2 Blind Equal Throughput (BET) .................................................................... 36
4.2.3 Proportional Fair (PF) ................................................................................... 38
4.3 OFDMA System .................................................................................................. 39
4.3.1 LTE Downlink Frame Structure ................................................................... 39
4.4 Fair Coexistence in Unlicensed Band .................................................................. 40
4.4.1 FBE-based LTE-LAA .................................................................................... 41
4.5 Network Simulation Framework and Parameter Settings ................................... 41
4.6 Simulation Platform ............................................................................................. 43
4.7 Simulation Results and Discussions .................................................................... 43
Chapter 5. Conclusion ................................................................................................... 48
Bibliography .................................................................................................................. 49

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