Thuyết trình môn thông tin di động LỊCH SỬ CỦA OFDM.doc

THE HISTORY OF OFDM
STEPHEN B. WEINSTEIN
Group 3:





HỌC VIỆN CÔNG NGHỆ BƯU CHÍNH VIỄN THÔNG
contentS
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$), "*')$-!'!"$++*$*!
 *&!"$ & ),
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! '$++*$*!)
The fdm background
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 * 012345 6768664 9 :67;4 4;7 <4 7; =>78> 76 87 ;?  76>68 74=44; >6 @  46:6> ;76?6
?;=7;6>4
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"6C69:4;=>78>6AB"
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;6@46@99;6844@96>
•
*0D015$G968>;6974;<E:6B6>4476=7746;7B4;B4@6?6C6649686764
The fdm background
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*0DH3456I64476=4699;@>6496@9=8>796=;9>7;974=776987;I33=>64
•
*760D2345"64476=4<79:9>4@6>4?;:;64>4@657;@668>69@J"9864476=4
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64<67;748;@>6=<746>9774=44;9;?6C6K'"L6>4K9>76)<746:66>947;7696>4L<47;;
@M7;E6B69"5;6779776>644?9694@6>4
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6468;@>6=46;:6;=69@"7;@6;=6=;6;=8>6764476=4!"
FDM had two drawbacks:
N6<476;?46<6>644?6C64867=94864@67<66764@6>4
N6>6;=8>6A7;?=>78>7;?46876=;9>7;4?;769??6674@6>4
*!"4476=469;=8>6A97O
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P5764@6>4>45
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'67>9?>>B;46B;>>;??8>464964>7!"4867

DENSE SUBCHANNELS
( ) ( )
( )
( )
2 ,
/ , 0 –1,
1 ; 0

0 ; 0 (1)
( )

n n n
n
s t a g t exp j f t
f n T n N
g t t T
g t t hoac t T
π
=
= ≤ ≤
= < <
= ≤ ≥
DENSE SUBCHANNELS
•
$B8;7:646"K*"L;867;76K8;44@>;=8>6AL97@>;M
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3
5
0
5Q5
B0
P
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667644=8>64577=676:>4J5;?76!"4>774764=;?764@6>4>496E69 C0
•
!867;7666:694><776"5>M6 CI@7<767:66A8;6756;:647697
1
0

2{ } 2/ ( )
N
k n
n
s a exp j nk N
π
−
=
=
∑
!"4476=
DENSE SUBCHANNELS
•
96:6>;86966>;97;4?;764864;?8>464596E69476;=@7;;?74=776E>7696>76475<7
@9>=769@747>>;:6>884867
4476=?;!"<76>B968696774=776E>764
DENSE SUBCHANNELS
•
)>7R@66A76969S4<;M7;;=8>6A975>>69!"B!$K;??467$L
•
;4M;7@769?7666=6747;!"J!$587>>=?4768;6447;68>6=67;?B8;7"<7
JIB8;7"
OFDM-OQAM implementation with staggered time-delayed subchannels(adapted from Saltzberg and Hirosaki ).
SIGNAL GENERATION USING THE DFT AND ITS FFT IMPLEMENTATION
•
646;98;@>6=;?"56?E67>667=>76>5>;46>8M69K!"L974>5<44;>:69@76""=8>6=677;;?76
"
•
%$'.6676976;7;;>4@6>4>4476">;9<6=8>6=677;66<66TU4@@6>4T
%R@9<97

SIGNAL GENERATION USING THE DFT AND ITS FFT IMPLEMENTATION
•
6 ""5 6A8>;7 76 86;97 9 4==67 8;86764 ;? 6A8;67>45 ?7;4  >67  " 7;  =@6 ;? 4;76B>67 "4 <7
=>78>66B46;?7664>74;?76464;76B>67"4
•
!"<;>9>4;5 4 V==6= 9%4;7690DH25488;7E>6A@>67>R7;;?4867=77<44@F677;?9;K4 $)L
?6C6B46>67:676?666
•
(476""=96!":@>65@77696@76;:6766>7:6;=8>6A7;?!"4>8;64494>66<96B6>6C>R7;
;7647;749
•
)W0HX9;764W02501X;76977667996767!"4>44=>7;6C>R4>664476=76?6C6
9;=6E>6A@>7;?!"88647;:6=96776<667876
ADSL: THE FIRST MAJOR OFDM APPLICATION
•
6E47=F;;4=6B;676988>7;<4$)K4==6797>4@4@6>6L)9@66:6477697#6>>@4<66&7>
9;76496E694>66>4476=477;>9<;M7=6@776;4@4@6>644>;401M>;?667
•
$=7S48;7;786  $) =;96=,8@>7 7; :;9 6A869 8;<6 874;? 76 4867= 76R69 @ :6 >6 ;46 ; 9668
6>>>58@>79?E>77;6:6?;4>6B64476=4
•
6$=7;896:4699=@744=6747766477446997K94>8;<6L;96<776E>776>9
;46;97;478>;?7<476984@4@6>6
ADSL: THE FIRST MAJOR OFDM APPLICATION
ADSL1 Technology
•
(464IYHB8;7"<74@64468769@UT0IYMR9
K@>;ML4=@;>76;?U333J4
•
&986;9;?U34=8>64

•
64=8>76;?7674=77694>4II31=>>;J4
•
697764=>78>6;?TIM@J487;88;A=76>1@J4
•
)@@943ZTI6469?;8476=9TTZIYY?;9;<476=
•
67;7>4@4@6>6@9<97,00R
ADSL2 + Technology
•
Y0I4@@946469
•
64=8>764UU0H=>>;J4
[ Note: 6 47>> 6<6 )5  @9 4476=4 <7 76 4;7647
4@4@6>64546764=64@64894=@;>76
49;64$)@787;U3DH4@@945;4=@;702HR;?
@9<97 $>767:6>5 )  46  1 MR 4=@;> 76 9
1HIY MR 4@6 485 488;7 8 7; 0Y3 @J4
9;<476=977692Y@J48476=
MEETING OFDM CHALLENGES:
THE CYCLIC PREFIX
•
";;9!"<767>8>4694864:66>464764=@;>76?666
•
$976:>;>86?A6C>7;76\=6=;]K94864;7=6L^;?766>@64697;=77674
•
$>86EA47668677;;?76>4787;?7674=77694>97686EA76:>
•
6>86EA<457;767;S4M;<>6965E478;8;469@+6>699'RWITX0D13
MEETING OFDM CHALLENGES:

THE CYCLIC PREFIX
•
$44=674=77694>4=8>64K4
B:
5Q54
B0
54
3
54
0
5Q54
B0
L_8797K
3
5Q5
B0
L_764=8>64;?766>=8>46648;466K
3
5Q5
:
L_
764=8>6966:694>K
B:
5Q5
B0
5
3
5
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5Q5

B0
5
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5Q5
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L
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-M)>R667>96:6>;86987>>6>67>7=7A6A8>7;?;<768797B*"B>86EAB6>B"4664;?
;867;496;8>64764@6>4
•
";6A=8>65:aI

MEETING OFDM CHALLENGES:
OVERCOMING HIGH PEAK TO AVERAGE RATIO
•
686M7;:668;<67;K+$+'L;?!"<4446;48;@>6=4764=@;>76?666
•
b6764=6=;9>7;>6:6>4469?;>>764@644;94_77a376<>>>>:6764=68;>799987;>6:>6
•
86M:>64;?6C67>@7@6:6
•
966944469=@6;?88;647;>=7+$+'>9=8>796>885;957;6646:7;;F67;59=
;476>>7;6A764;5Q
•
&664769"7R6>9;7@7696><;M;4>847;==R6+$+'
OFDM-based frequency-hopping systems of Hedy Lamarr
•
$)<476E47<96>46988>7;?;""B@469!"5
@7768696644;;?;7688>7;5!"B@469
?6C6B;884476=4

•
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4867=76C6?;:;976?666?;7;77F==
•
*7<4;7@>=8>6=676976#>67;;74799
K* 13I0Y0L
•
*78866976;76A7;?6>>>=;@>6;==7;476">;
">4!"4476=
Frequency-hopping system
DVB-T:Digital Video Broadcasting – Terrestrial
•
6#B@;9476464I3U1K\I%]L;10DIK\1%]L"96=8>;4;969!"K!"L
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$>67669976:>587;;6?;776!"4=@;>>6758;:96499698;767;776;47;?>;<64867>6?E6)867>6?E664?;=
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6#B4476=
The other major two-way wireless applications of OFDM
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b$/K* 13I0HL,<6676"=:64=4U3DH8;745;4?6<40I157;;==;9766>4?;=76;=>I3R
9;<76;96;?0R
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(b#,4>7<96@9K(b#L864;>667<;M44!"564867=446=6769YI1RM456488;70I1!"
4@6>4
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THANK YOU !