My slides presentation when I got bachelor degree, Telecommunication Engineering. That is about Femtocell and Interference Management

1. Simulation and Analysis
Interference Management Algorithm
in LTE Femtocell
Toha Ardi Nugraha
111098027
1st Advisor : Nachwan Mufti A, ST.,MT
2nd Advisor : Hazim Ahmadi, ST.,MT

2. Contents
– Preliminarily
• Background
• Objectives
• Problems
• Limitations
– Basic Theory
– Scenario and Simulation
– Analysis

3. Background
Over Capacity
In Building
Pico Cell
BS indoor (DAS)
downlink Repeater (DAS)
Cell Edge
New Solution Added Services

4. Femtocell ?
Plug and Play
Broadband cable
Does not use network planning
Self organizing Network (SON)
Access Control (CSG), etc
Network License (UMTS, CDMA)

5. Objectives
Interference characteristic femto
Sub-carrier frequency allocation
Fractional Frequency Reuse (FFR)
Scenario and model

6. Problems
Scenario
Configuration, parameter (macro – femto)
Interference management algorithm
Simulations and analysis

7. Limitations
LTE , downlink and co-channel interference,
macro-femto, and femto-femto
2600 MHz, urban area, and bandwidth 10 MHz
Using SISO and Omni directional antenna.
Not discussing about power control and
handover schema.

8. Contents
– Preliminarily
– Basic Theory
• LTE Femtocell
• Access Control
• Inter-Cell Interference
• Fractional Frequency Reuse
– Scenario and Simulation
– Analysis

9. LTE Femtocell Architecture [3GPP TS.22.220]
HeNB : Home eNode B (LTE femto)
HeNB GW : HeNB Gateway
HSS : Home Subscriber Server

10. LTE Architecture [3GPP TS 36.300]
eNB : evolved Node B
MME : Mobility Management Entity
S-GG : Serving Gateway

11. Access Control
Close Access
Open Access
Hybrid Access
Status Close Open Hybrid
Preferential
Subscriber Access Access
Access
Non-
No Access Access Limited Access
Subscriber

12. Femtocell Problem #1: Inter-Cell Interference
Downlink Interference
Co-Channel Interference

13. Femtocell Problem : Co Channel Interference
• Co-Channel Interference: caused by the use of the same frequency
Formula :
• Signal to Interference Noise Ratio (SINR)
• Data Rate

14. Model Propagation
Formula :
• Outdoor (SUI)
c
• Indoor   a  bhb 
hb
 f 
PLf  6 log10  
 2000 
Lwalls = 7 dB, 10 dB, 15 dB
 h
  10,8 log10   ; typeA dan B
 2
PLh  
 h
 20 log10   ; typeC

 2

15. Contents
– Preliminarily
– Basic Theory
– Scenario and Simulation
• Cell Edge
• Close Access
• Open Access
– Analysis

16. Start
Procedure Scenario Simulation Parameters
(eNB and HeNB) LTE
Algoritma Management
Interference (FFR)
Simulation Scenarios with Access
Control Method (Cell Edge)
Open Access Close Access
Simulation and Collect
Data
Signal to
Interference Noise Data Rate
Ratio (SINR)
Scenario
is over?
Finish

17. Parameter Simulation
Simulation Software :
- Matlab , for SINR, data rate
- Planet Mentum, for SINR, Data Rate, and coverage visualization
Value
Parameter
macro femto
Cell 19 Macro(eNB) 20-160 in eNB1
Transmit power FFR : 15 : 22 W 20mW
Bandwidth 10 MHz
Sub-carrier 600
Sub-carrier spacing 15 KHz
Size of cell, and Center Zone 1 km, 63%
Pathloss SUI (Outdoor), Indoor Propagation

18. Fractional Frequency Reuse (FFR)
FFR (Fractional Frequency Reuse) is one effective solution of inter-cell interference
control.
FFR can control the interference in cell edges to enhance the frequency reuse factor
and performance in the cell edges.
System Layout Model

19. Scenario FFRm-fr
FFRm-f (FFR macro only)
Sub-Carrier
Identification Macro Femto
Center A 50 % 40% 60%
Sector 1 B (50/3 )% (60/3) % (40/3)% Random
Sector 2 C (50/3 )% (60/3) % (40/3)% Random
Sector 3 D (50/3 )% (60/3) % (40/3)% Random
Cell Center Cell Center Cell Center
Power Cell 1 Power Cell 1 Power Cell 1
Frequency Frequency Frequency
Cell Edge Cell Edge Cell Edge
Total System Total System Total System
BW BW BW
Ex : 50%, cell center 300 subcarrier,
Bandwidth : 10 MHz = 600 sub-carrier cell edge @100 sub-carrier

20. Scenario FFRm-f
eNB1
FFRm-f (FFR macro and femto)
Sub-carrier
No Location in cell
Sector 1 Sector 2 Sector 3
Center (Omni) C1 (A) C2(A) C3 (A)
1 Macro
Edge E1 (B) E2 (C) E3 (D)
Center C1 (C,D) C2(B,D) C3 (B,C)
2 Femto
Edge E1 (A,C,D) E2 (A,B.D) E3 (A,B,C)
Example : SINR UE macro (eNB1, sector E1)

21. Cell Edge (Femto Close Access)
User can not access femto
Weak signal from macro
Strong interference from femto

22. Cell Edge (Femto Open Access)
User can access femto and macro
Weak interference from macro

23. Contents
– Preliminarily
– Basic Theory
– Scenario and Simulation
– Analysis
• SINR
• Data Rate
• Simulator

24. Signal to Interference Noise Ratio (SINR)
Comparison SINR with distance (dB)
Distance
from macro
FFR FFRm-fr FFRm-f
(m)
300-400
23,37 23,37 23,37
8x
16,23 16,23 16,23
400-500
2,16 2,16 2,16
500-600
4,10 15,64 26,61
600-700
2.57 13,25 24,22
700-800
1.70 13,25 24,,22
800-900
0.64 12,19 23,16
900-1000
Cell Center Cell edge
SINR increased 8x ≈ 22 dB

25. SINR (open access)
SINR Increased
average 0,0002 dB
@20 femto

26. Data Rate (Open Access)
comparison data rate macro + femto (edge) (Mbps)
Femto
FFRm40-f FFRm50- f FFRm60-f FFRm40-fr FFRm50-fr FFRm60-fr
20 9,890 8,241 6,595 5,445 4,537 3,630
40 11,429 9,524 7,619 5,917 4,930 3,944
.. .. .. .. .. .. .
160 13,089 10,097 8,725 6,350 5,291 4,233
Using FFRm-f,
Data Rate
increased 2x
then FFRm-fr

27. SINR (close access)
“Close Access”
Decreased SINR
System

28. Data Rate (Close Access)
Data rate User Macro (Center+Edge) FFRm-f dan FFRm-fr (Kbps)
Femto
FFRm40-f FFRm50- f FFRm60-f FFRm40-fr FFRm50-fr FFRm60-fr
20 485,91 404,92 323,94 181,34 226,62 271,90
40 280,26 233,55 186,84 98,580 123,17 147,75
.. .. .. .. .. .. ..
160 80,293 66,911 53,528 26,549 33,127 39,705
“Close Access” Decreased
Data Rate System

29. Data Rate Total (Open Access)
Data rate Macro + Femto User (Center and Edge) (Mbps)
Femto
FFRm40-f FFRm50- f FFRm60-f FFRm40-fr FFRm50-fr FFRm60-fr
20 24,6551 26,693 26,275 20,206 22,989 23,312
40 26,190 27,975 27,301 20,678 23,382 23,626
.. .. .. .. .. .. ..
160 27,849 29,935 28,407 21,111 23,743 23,915
Up to ≈ 30 Mbps

30. Simulator : Mentum Planet 5.0 (LTE)
Downlink C/(I+N)
Downlink Average Data Rate

31. Simulation Result (Data Rate)
• In Simulator, FFRm50-f is also the best scenario
to increase data rate in network.
Average data rate in macro (Mbps)
femto
FFRm40-f FFRm50- f FFRm40-f FFRm40-fr FFRm50-fr FFRm60-fr
20 5,688 8,088 8,047 5,713 7,124 7.094

32. Conclusions
FFR (macro and femto) can increase SINR about 22 dB or 8x
in macro cell edge.
"close access" will cause a decrease in SINR and data rate of the macro
network due to the CCI (Co-Channel Interference). (FFRm40-f method)
Increase femto in macro cell edge and use the "open access ", then the
data rate at the cell edge network also grew. FFRm40-f is effective
method in cell edge and FFRm50-f (system)
Simulations indicate that the addition femto using-f FFRm50-f scenario is
also the most effective method

33. Suggestions
Research about femto (OFDMA)
Other Method (Power Control)
Tools Simulation (femto simulator)

34. Thank You
alhamdulillah.com