fyp presentation sem1
DESCRIPTION
final year project presentationTRANSCRIPT
FYP SEM 1 PRESENTATION
INTERFERENCE MITIGATION IN LTE/LTE-A NETWORKS
NAME: INDIRA KARIMOVA MATRIC NUMBER: KEW100701 SUPERVISOR:ASSOC PROF.DR. CHOW CHEE ONN
OBJECTIVES
• To study of performance of LTE-Advances networks with and
without using interference mitigation approaches.
• To compare the performance of the three major frequency
reuse schemes which are Integer Frequency Reuse(IFR),
Fractional Frequency Reuse(FFR) and Soft Frequency
Reuse(SFR) in macrocell and femtocell networks in LTE
• By using Matlab result is investigated in our result.
INTRODUCTION • This project focuses on the performance of interference
mitigation techniques in LTE/LTE-A networks with focus on
frequency reuse.
• MITIGATION TECHNIQUES WITH IFR,FFR,SFR.
• MACRO AND FEMTOCELL
The Concept of Femtocell
Femtocells – very small size, low power home base station that works with frequency bands and can improve the network coverage. Base Station-Uplink/Downlink
Interfering mobile terminal - same cell
Interfering mobile terminal- adjacent cell
Interference Mitigation
Conventional [Integer] Frequency Reuse
• Frequency Reuse 1 • Same frequency is reused by each
sector • High spectral efficiency • Large inter-cell interference • Cell edge users can rarely retain
connection
Frequency Reuse 3 Same frequency is reuse every 3 sectors Low spectral efficiency Low inter-cell interference Cell edge users have fairly good connection quality.
- Cell-edge band using frequency reuse 3, allocated to the cell edge users - Cell center band using frequency reuse 1, allocated to the users in the center of the cell
-Whole bandwidth can be reused in each cell in contrast to FFR. -Inner-uses all sub-bands with less power; - Outer-uses pre-served sub-bands with higher power; (orthogonal to each other) - The reserved band at each cell is allocated for center users with restricted power
SIMULATION PARAMETERS • The following table summarizes the network’s parameter’s values
during the simulation.
Parameter Value
Celcullar layout Single macrocell
Macrocell radius 250m
Femtocell radius 30m
Bandwidth 20MHz
Modulation Mode QAM64
Carrier frequency 2Ghz
Subcarriers spacing 15kHz
Noise power density 174dBm/Hz
Size of one cell 500m
Macro BS TX power 46dBm
Femto BS TX power 11dBm
Outdoor wall loss 20dB
Size of map 500m
Size of center zone 0.63 of macro coverage
Correlation distance 40m
SIMULATION SCENARIOS
• Scenario 1: Co-channel operation. The worst case of
cross-tier interference, where no frequency partition or
power control is applied and both femto - macrocells are
using the same spectrum.
• Scenario 2: Apply of IFR. When Integer/Incremental
Frequency Reuse of factor 3 is employed by Macro base-
station and femtocells measurements
• Scenario 3: Apply of Soft Frequency Reuse or Fractional
Frequency Reuse.
SIMULATION RESULTS FOR CASE 1 Case 1 is presented in Figure below where I have considered 10 femtocells, 10
femtocell users and 1 macrocell user. The Bandwidth is chosen as 20 Mhz and the
modulation as 64QAM.
Worst case scenario where no interference
mitigation control. Experiencing low SINR
as depicted by dim red color intensity
Macro-User’s data rate map for
instance of the interference during
configuration stages.
SIMULATION RESULTS FOR CASE 1
• COMPARISON => IFR < FFR < SFR
SFR
FFR
It improves greatly the cell-edge throughput
It also greatly improve cell-edge throughput except at the bottom left.
It significantly improves the overall system SINR and hence data rate.
IFR
SIMULATION RESULTS FOR CASE 2
• Case 2 is presented in Figure below where I have considered 12 femtocells, 12
femtocell users and 2 macrocell users. The Bandwidth is chosen as 20 Mhz and the
modulation as 64QAM.
Worst case scenario where no interference
mitigation control. Experiencing low SINR
as depicted by dim red color intensity
Macro-User’s data rate map for
instance of the interference during
configuration stages
SIMULATION RESULTS FOR CASE 2
• COMPARISON =>IFR<FFR<SFR
FFR
SFR
It improves greatly the cell-edge throughput.
IFR
Also slightly improve cell-edge throughput except at the bottom left. It significantly improves
the overall system SINR and hence data rate.
SIMULATION RESULTS FOR CASE 3
• Case 3 is presented in Figure below where I have considered 24 femtocells, 24
femtocell users and 1 macrocell user. The Bandwidth is chosen as 20 Mhz and the
modulation as 64QAM.
Worst case scenario where no interference
mitigation control.
Macro-User’s data rate map for
instance of the interference during
configuration stages
SIMULATION RESULTS FOR CASE 3
• COMPARISON =>IFR<FFR<SFR
FFR
SFR
No improvement (as power control) the overall system SINR and hence data rate.
Its also slightly improve cell-edge throughput bellow/above-side .
It improves slightly the cell-edge throughput .
IFR
RESULTS = IFR < SFR
IFR performs better in cell center.
The comparison is made between IFR and SFR schemes to test which scheme will perform better in improving cell-edge throughput.
BUT! 10 femtocells
10 femtocell users 1 macrocell user
12 femtocells, 12 femtocell users 2 macrocell users
24 femtocells, 24 femtocell users 1 macrocell user
SFR method is implemented and showing the positive result in increasing the data rate at the cell-edge and all the cell-edge users experience high SINR (and hence throughput)
Explanation IFR < SFR
Conventional Frequency Reuse Soft Frequency Reuse
Reuse-1 Reuse -3
Each cell uses the same
frequency, high spectral
efficiency, large intercell
interference, cell edge users can rarely retain connection
Same frequency is reuse every 3 sectors , low spectral efficiency.
This methods uses the same
frequency expect for the cell-edge
areas. For the cell-edge areas, the
frequency band is changed so that
adjacent cells do not cause
interference.
Average throughput performance for macro users at center
CASE 1
CASE 2
CASE 3
Average throughput performance for macro users at center
Throughput for macro users at cell’s borders.
CASE 1
CASE 2
CASE 3
Throughput for macro users at cell’s borders.
Experimental Results The table presents a comparison of all methods, versus the number of femtocells.
Femtocells No IFR FFR SFR
Throughput
(Mbps)
Throughput
(Mbps)
Throughput
(Mbps)
Throughput
(Mbps)
2 68.99 69.35 68.99 69.17
4 68.81 69.17 68.81 68.99
6 68.03 68.38 68.03 68.21
8 65.19 65.51 65.19 65.35
10 56.97 57.20 56.97 57.08
15 51.12 51.30 51.12 51.21
20 14.11 14.12 14.11 14.12
25 11.64 11.65 11.64 11.65
No ICIC = Red
IFR = Yellow
FFR = ***
SFR = Green
Performance : Average
SEM 1 PROGRESS For semester 1, my works focused on analyzing the LTE different interference mitigation techniques and simulation study and the result
obtained was investigated and analyzed according to the Matlab
Simulation methods.
Gantt chart for sem 1 Week 1 2 3 4 5 6 7 8 9 10 11 12 13 14
LTE Network
Identify interference in LTE/LTE-Advanced network
Searching simulation software
Simple simulation on IFR,FFR, and SFR
Identify femtocell interference management methods
Learn basic coding of IFR,FFR, and SFR
Simulate femtocell interference on Matlab
Analyse different interference mitigation
Simulation campaign
Data Analysis
Progress Report
PLANNING FOR SEM 2 WORKS • In the next sem, I will attempt to combine the desirable features from the
various existing frequency reuse schemes into a new integrated scheme.
• And I will attempt to design a new method that can reduce the
interference that occur in the the frequency reuse schemes used to
mitigate the inter-cell interference that caused by femtocells section
highlighted in the previous diagram.
• Make some modifications on the coding which Matlab code used for
simulation will be conducted in order to improve the effectiveness of the
frequency reuse schemes.
Gantt chart
Scheduled To-Do Things 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Study the code on Frequency Reuse Schemes
Analyze the Frequency Reuse Schemes
Perform more comprehensive Comparison study
Analyze on simulation results
Write final report and presentation
CONCLUSION • IFR,FFR and SFR schemes proposed with three cases to enhance the system capacity.
• IFR used up all the frequency spectrum which gives a good amount of throughput but
it may lead to strong co-channel interference at cell edge.
• FFR can improve the cell edge data capacity but this scheme is not fully deploy the
entire frequency spectrum which wastes the frequency resources.
• SFR is a good frequency partition method with power control on the physical resource
block (PRB) can resolved FFR issues.
• My next job to investigate the implementation of frequency reuse scheme or power
control in femtocells.
• Power control is better in data capacity enhancement but at the expense of some
frequency channels as it involves a lot of communications between macrocell and
femtocells.
• Also, there may still be other new unexplored methods for us to discover to reduce the
interference mitigation.
Future Work For Interference Coordination Method
THANK YOU