1. Report on Channel Model
Chrysovalantis Kosta
Good Afternoon Sir
This afternoon I will share with you my report of Femtocell
Let’s start with femtocell presentation!

2. Agenda Wireless Channel Characteristics Path loss Shadowing
And how we may simulate these??

3. Wireless Channel Characteristics
Wireless Channel of different com terminal
Path Loss
Large scale
Long duration
Shadowing
Medium Scale
Medium Duration
Multipath Fading
Small Scale
Small Duration
Generally, the wireless channel of different communication terminals can be expressed with a multiplicative propagation mechanism of three nearly independent fading components:
path loss, shadowing and multipath.
Each one of them has a different scale and different duration.
It can be scaled as ‘large’, ‘medium’ and ‘small’ and
It can be termed as ‘long, ‘medium’ and ‘short’, according its duration.
fading effect ?
duration ?

4. Path Loss (Large-scale fading effect)
Example
Path Loss for Urban
Free Space Loss
  is the path loss in decibels
  is the path loss exponent
is the distance between the transmitter and the receiver,
is a constant which accounts for system losses
  n=3.76
C= 128
colorbar
terminals can be formulated as
C= 127
  n=3

5. Example from LTE simulator50
100
150
200 20 40 60 80
120
140
160
180 70 90
110
130
networkPathlossMap.plot_pathloss(cell ID) / .plot_pathloss_all

6. Shadowing (Medium-Scale Fading effect)
Shadowing (Log-normal fading loss)
Shadow fading is cause by obstacles in the propagation path
Mainly from irregularities of the geographical terrain.
We may simulate this fading by using a normal/guassian variable with mean =0 and a positive std from 8 – 10 dB.

7. Shadowing (Medium-Scale Fading effect)
Shadowing (Log-normal fading loss)
1-D dimensional shadowing
New value
Old value
Forgetting factor

8. Shadowing (macro-cell diversity )
As shadowing effects occur over a large area, in order to be able to capture the dynamics affecting macro-cell diversity in a realistic way, a two-dimensional Gaussian process with appropriate spatial correlation is desirable.

9. Shadowing Shadowing (Log-normal fading loss) 2D dimensional shadowing
Impulse
Response
Table
Gaussian Table
2D convolution

10. Evaluation of Shadowing model
Calculating the mean value (should be 0)
Calculating the std value (should be std)
Plotting the histogram

11. Example from LTE simulator
networkPathlossMap.plot_shadowing(cell ID) /.plot_both_path_shawdow_all

12. Examples from LTE simulator

13. Examples from LTE simulator
networkPathlossMap.plot_pathloss_all
networkPathlossMap.plot_both_path_shawdow_all

14. Questions and Answers This brings me to the end of my presentation!
Thank you for your attention!
Now, I would be happy answering any question that you may have !

15. Fast Fading Channel Model
The channel model consists into mobile wireless channel with L moving scatters.
The Fourier transform of the channel response is the time varying frequency response which can be described as:
where
hl  the complex amplitude
τl  time delay of the lth path.

16. Simulating flat fast fading
Inputs:
Ns : number of samples in the generated fading impulse response
Ts : Sampling Interval in seconds
Fd : Maximum Doppler Frequency in Hz
M : # of Sinusoids
Output:
Gt : complex channel impulse response =

17. Modeling flat fast fading (Matthias method )Fd
Ns & Ts

18. Evaluation of flat fast fading channel model
Phase 1
Autocorrelation of Real part (Fig.1)
Autocorrelation of Imag. part (Fig.2)
Cross correlation of Real part (Fig.3)
Autocorrelation of Amplitude (Fig.4)
Phase 2
Normalized LCR (Level crossing rate) (Fig.5)
Normalized AFD (Average Fading Dur.) (Fig.6)
Fading Amplitude Fig.7

19. Matthias Patzold Autocorrelation of Real part
Autocorrelation of Imag. part
Cross correlation of Real part
Autocorrelation of Amplitude

20. Jakes Model Autocorrelation of Real part Autocorrelation of Imag. part
Cross correlation of Real part
Autocorrelation of Amplitude

21. Yahong Autocorrelation of Real part Autocorrelation of Imag. part
Cross correlation of Real part
Autocorrelation of Amplitude

22. Optimal Autocorrelation of Real part Autocorrelation of Imag. part
Cross correlation of Real part
Autocorrelation of Amplitude

23. Matthias Patzold Level crossing rate Average Fading Duration Fading
Amplitude

24. Jakes Model Level crossing rate Average Fading Duration Fading
Amplitude

25. Yahong
Level
crossing
rate
Average
Fading
Duration
Fading
Amplitude

26. Channel Impulse Response
Signal power
in dB
Delay of each path in sec

27. Examples of ITU models
Here, we display some examples of most favourable ITU models.
Some of the m they may charactarize as indoors or outdoor depending on their average delay spread.
All these are modeled in Vienna.

28. Simulating Selective Fading
Simulate multiple flat fading layers
Multiply and shift according to the channel profile
(in terms of multipath signal strength and delay)

29. Example of ITU model using PedB
Doppler frequency at 100Hz
Sampling interval 1/
Number of Samples 4000
Number of Sinusoids 10
Furthermore, we model the channel impulse response of the PedB channel model at this speed
The simulation code examples will be available on my personal webpage.
On this axis we may impulse response in time domain
And on this in frequency domain.
The frequency Doppler of this example is 100Hz, the total bandwidth is 1.4 MHz for 4 secs.
Note that the points with dark colour depict deep fading and the points with red color depict non-deep fading.

30. Questions and Answers This brings me to the end of my presentation!
Thank you for your attention!
Now, I would be happy answering any question that you may have !