BSc senior project

1. Implementation of Synchronization
Algorithms for Media Flo Systems
1
By
Ahmad ElMoslimany
Supervised by:
Prof. Mirette Sadek

2. Agenda
• Introduction to Media FLO system
• Media FLO Transmitter
• Media FLO Receiver
– Synchronization
– Equalizer
– Turbo decoder
– Reed Solomon decoder
• Simulation results & !!!!!!
2

3. Agenda
• Introduction to Media FLO system
• Media FLO Transmitter
• Media FLO Receiver
– Synchronization
– Equalizer
– Turbo decoder
– Reed Solomon decoder
• Simulation results & !!!!!!
3

4. What is ?
•American standard for video broadcast.
•Mainly used in mobile TV.
•An OFDM based system.
4

5. Overview
• Multicarrier modulation.
• Orthogonality.
5

6. Overview (cont’d)
• Cyclic Prefix Addition.
• Avoid ISI and ICI.
6

7. Agenda
• Introduction to Media FLO system
• Media FLO Transmitter
• Media FLO Receiver
– Synchronization
– Equalizer
– Turbo decoder
– Reed Solomon decoder
• Simulation results & !!!!!!
7

8. Transmitter
Block diagram:
8

9. Super frame Structure
• OFDM symbol = 4000 active sub-carrier
• B.W = 5.55 MHz
• Frequency spacing = 1.35 KHz
9

10. Agenda
• Introduction to Media FLO system
• Media FLO Transmitter
• Media FLO Receiver
– Synchronization
– Equalizer
– Turbo decoder
– Reed Solomon decoder
• Simulation results & !!!!!!
10

11. Receiver
Block diagram:
11

12. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
12

13. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
13

14. Synchronization theory
Synchronization types
Frame
synchronizat
ion
CFO
estimation
Trigger point
estimation

15. Synchronization theory (cont’d)
Synchronization
Algorithms
Pilot aided method Blind method

16. Frame synchronization
• Detect the start of the frame.
• Search for known preamble.
• OFDM preamble has unique properties.
• Based on correlation technique.

17. Carrier Frequency Offset (CFO)
•Local oscillators mismatch.
• ICI occurs.
•Loss of orthogonality.

18. CFO(cont’d)
• Fine frequency offset, Through maximum
likelihood estimator
• Coarse frequency offset, through correlation
process.
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19. Trigger point estimation
•Select NFFT window.
• Avoid ISI.

20. Synchronization (cont’d)
Synchronization
Algorithms
pilot aided method Blind method

21. Blind Method
coarse trigger point estimation through ML estimator




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22
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22. Synchronization (cont’d)
Synchronization
Algorithms
pilots aided method Blind method

23. Pilots Aided Method
Trigger point fine tuning using pilots aided method
using the following metric.
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0
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2c
qPt
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24. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
– Frame synchronization
• Blind method
• Pilots aided method
– Symbol synchronization
– Carrier frequency offset estimation
24

25. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
– Frame synchronization
– Symbol synchronization
• Blind method
• Pilots aided method
– Carrier frequency offset estimation
25

26. Frame synchronization
Block diagram :

27. Frame synchronization (cont’d)
• Correlation properties of TDM1

28. Frame synchronization
28
• Running cross correlation between TDM1 and
another symbol

29. Frame synchronization
• Correlation properties of TDM1 (cont’d)

30. Frame synchronization (cont’d)
• Peaks of cross correlation

31. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
– Frame synchronization
– Symbol synchronization
• Blind method
• Pilots aided method
– Carrier frequency offset estimation
31

32. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
– Frame synchronization
– Symbol synchronization
• Blind method
• Pilots aided method
– Carrier frequency offset estimation
32

33. Maximum Likelihood (ML)
estimator
Block diagram :

34. Outputs from ML
34

35. Outputs from ML (cont’d)
35

36. Performance of ML
36
• Histogram of the estimated trigger point

37. Performance of ML (cont’d)
37
• Histogram of the estimated fine CFO

38. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
– Frame synchronization
– Symbol synchronization
• Blind method
• Pilots aided method
– Carrier frequency offset estimation
38

39. Trigger Point tuning using pilot aided
method
• Block diagram :

40. CIR estimated
40

41. Performance of the fine tuner

42. Synchronization
• Synchronization theory.
• Application of synchronization algorithms in
Media FLO system.
– Frame synchronization
– Symbol synchronization
• Blind method
• Pilots aided method
– Carrier frequency offset estimation
42

43. TDM1 correlation
43
• Cross and Auto correlation of TDM1, CFO=1

44. TDM1 correlation
44
• Cross and Auto correlation of TDM1, CFO=2

45. Coarse CFO estimator
45
Peaks of the correlation

46. Agenda
• Introduction to Media FLO system
• Media FLO Transmitter
• Media FLO Receiver
– Synchronization
– Equalizer
– Turbo decoder
– Reed Solomon decoder
• Simulation results
46

47. Simulation results
• AWGN , mode 0 (QPSK ,TR=1/3 ,RS=7/8)
47

48. Simulation results (cont’d)
• AWGN , mode 2 (16QAM ,TR=1/3 ,RS=7/8)
48

49. Simulation results (cont’d)
• TU6 ,mode 0
49

50. Simulation results (cont’d)
• TU6 ,mode 2
50

51. Any Questions ?
51

52. Thank You
52