Corrupt the signal waveform Degrade the performance of communication systems

Transcription

1 Nie Nie : rd luui pwer i ye Crrup he igl wver Degrde he perre uii ye ure Nie: rd wderig ree eler i reir herl ie, rd lw hrge i eidur jui h ie, e. ddiive ie Zer-e Whie Gui-diribued Nie, pwer perl deiy / Urreled wih he igl Trier Chel Nie WGN eeiver erre eure: lg igl--nie i N y Digil i-errr-e E EG30-II p. II-89

2 Nie: igl--nie i ue he hel irdue diri d reeiver i lier eeived igl Nie eeiver y N verge pwer ege igl verge pwer ie he he reeiver upu reeiver upu y where d re he igl d ie wver he reeiver upu. N EG30-II p. II-90

3 Whie Nie d ilered Nie Whie ie: l perl deiy ver wide rge requeie τ / / ilered whie ie: τ iler H H H d H d / / EG30-II - Lw-p iler - bd-p iler p. II-9

4 dp Nie r bdp ye, whih lii he bdwidh he ie, e he ie luui re reried. he bdwidh he ie bee ll pred he eer requey, i bee pible pprie i wih phr repreei. θ Here i h pri he ie whih i he i-phe pe d i he qudrure pe i he phr repreei. The plee phr repreei he rrwbd rd ie i [ j ] e j θ EG30-II where i he eer requey. j e{[ j ] e } whih i kw he bdp repreei ie. i p. II-9

5 dp Nie L e 0 [ ] 0 i 0 0 i 0 The upu he lw-p iler i e [ 0] L The pwer perl deiy i I{ } I{[ T T 0 ] li li T T T T N N T 0 T 0 li T T L L } EG30-II p. II-93

6 EG30-II p. II-9 dp Nie r rd ie, he verge he r prdu ge zer, hu L ] [ 0 0 The e r llw i he e er by iderig i, yieldig L ] [ 0 0 Hee, L ] [ 0 0 Thu, heir e-qure vlue re equl; The e-qure vlue bdp rd ie i i Q

7 dp Nie EG30-II p. II-95

8 EG30-II p. II-96 Hee, d he perl deiie d re dp Nie Eple: Whie ie wih pwer perl deiy / i ilered by regulr bdp iler wih H, eered d hvig bdwidh W. id he pwer perl deiy d. Clule he pwer i, d. lui: ie he iler i regulr wih H, he pwer perl deiy he upu ie i: elewhere W W 0 r W wer d re W d W W wer i W W d d W W W W

9 Nie i ebd C. ye ebd rii: igl i ried wihu y duli. ue bh he rier iler d reeiver iler re idel lw-p iler wih bdwidh W L Chel Nie WGN L, ue dirile hel: K d where K d d re he pliii/eui d ie-dely, repeively. verge upu igl pwer: reeived pwer verge upu ie pwer: N d d EG30-II p. II-97

10 Nie i ebd C. ye Eple: Cider lg bebd uii ye wih ddiive whie ie. The rii hel i ued be dirile d he pwer perl deiy whie ie i / i 0-9 w per herz W/Hz. The igl be ried i udi igl wih -khz bdwidh. he reeiver ed, C lw p iler wih 3-d bdwidh 8kHz i ued lii he ie pwer he upu. Clule he upu ie pwer. lui: r C lw-p iler 3-d bdwidh8khz, he requey repe i / j C H where C / jc j H 3d bdwidh [ ] / 8000 verge upu ie pwer: H d d EG30-II µw p. II-98

11 Nie i pliude Mduled ye eeived duled igl Nie Deer Dedulr L y eeiver The bdp iler lii he u ie uide igl bd h rehe he dedulr u--bd ie N N N Nrrwbd ilered ie: i wer perl deiy: EG30-II eeived igl pwer: p. II-99

12 Nie i D-C ye I D-C ye, he reeived duled igl i: eeived duled igl Nie Cider he deduli by yhru deei: eeiver i where i he ege igl whih i bd-liied wih bdwidh Dedulr Ipu igl pwer he dedulr: Ipu ie pwer he dedulr: L y N 0 - EG30-II p. II-00

13 EG30-II p. II-0 Nie i D-C ye Oupu igl pwer er L: y Oupu ie er L: Oupu igl er L: y L { } i ] [ i L L L Oupu ie pwer er L: Q N bere dedulr: N i i N y N Oupu N er dedulr: The deer dedulr iprve he N i D-C ye by r. Thi iprvee reul r he h he here deer reje he qudrure ie pe i he ipu ie, hereby hlvig he e-qure ie pwer. N r D-C

14 EG30-II p. II-0 Nie i D-C ye Eple: D-C ye wih ddiive whie ie i deduled by yhru deer wih phe errr, i.e.. The rigil ege igl i. hw h where γ i he upu N whe he yhru deer h phe errr. Oupu igl pwer er L: y Oupu ie er L: i i Oupu igl er L: y L i L Oupu ie pwer er L: Q γ y N Oupu N er dedulr: i γ N γ lui:

15 Nie i ye I ye, he reeived duled igl i: ˆ i eeived duled igl Nie Cider he deduli by yhru deei: where i he ege igl whih i bd-liied wih bdwidh eeiver Dedulr L y ˆ i i N EG30-II p. II-03

16 EG30-II p. II-0 Nie i ye Ipu ie pwer he dedulr: Ipu igl pwer he dedulr: i ˆ i ˆ i ˆ i i ˆ Oupu igl he dedulr: y L Ipu igl he dedulr: Ipu ie he dedulr: Oupu ie he dedulr: L Oupu igl pwer he dedulr: Oupu ie pwer he dedulr: y

17 EG30-II p. II-05 N bere dedulr: N i i N y N Oupu N er dedulr: Nie i ye The deer dedulr de iprve he N i -C ye. N r

18 Nie i D-LC M ye I D-LC M ye, he reeived duled igl i: [ ] where i he ege igl whih i bd-liied wih bdwidh Cider he deduli by yhru deei: eeived duled igl Nie Dedulr L y eeiver i [ ] N EG30-II p. II-06

19 EG30-II p. II-07 Nie i D-LC M ye Ipu ie pwer he dedulr: Ipu igl pwer he dedulr: i Oupu igl he dedulr: y L Ipu igl he dedulr: Ipu ie he dedulr: Oupu ie he dedulr: L zer e ege igl 0 ue y revig he DC er, give y

20 EG30-II p. II-08 Nie i D-LC M ye Oupu igl pwer he dedulr: Oupu ie pwer he dedulr: y N bere dedulr: N i y N Oupu N er dedulr: r D-LC N vid diri ver-duli N N D-LC i le 3-d wre h h i D-C d ye

21 Nie D-LC M ye I D-LC M ye, he reeived duled igl i: [ ] Cider he deduli by evelpe deei: eeived duled igl i Nie where i he ege igl whih i bd-liied wih bdwidh Ipu he evelpe deer: eeiver Evelpe deer Dedulr r [ ] [ i ] EG30-II p. II-09

22 EG30-II p. II-0 Nie D-LC M ye r lrge ipu N:, >> { } i i Oupu he evelpe deer: { } r j e r r where Ipu he evelpe deer: ; r evig he DC pe, give r whih i billy he e he upu igl, y, r yhru deei D-LC igl wihu he lig r ½. Thu, r high N reeiver ipu, he perre yhru deer d evelpe deer i he e.

23 EG30-II p. II- Nie i D-LC M ye r ll ipu N:, << { } r ll uig le r ll v v v v v v v v v r α α α Thu, r ll N reeiver ipu, he igl d ie re lger ddiive. The igl uliplied by ie be diiguihble. N eigul upu N be deied.

24 Nie i pliude Mduled ye Eple: uig iuidl duli, hw h, i M ye wih evelpe deei, he upu N i give by N where i he duli ide r M. lui: r iuidl duli, Uig N r M r D-LC Thu, N N EG30-II p. II-

25 Nie i pliude Mduled ye Eple: Cider M ye wih ddiive herl ie hvig pwer perl deiy /0 - W/Hz. ue h he bebd ege igl h bdwidh khz d he pliude diribui hw by he igure. The igl i deduled by evelpe deei d pprprie p-deei ilerig. ue duli ide. - 0 id he iiu vlue he rrier pliude h will yield N 0d. EG30-II p. II-3

26 Nie i pliude Mduled ye lui: [ ] d 0 d 6 r, khz, /0 - W/Hz, 6 7 N wih 7 [ ] 6 r N N 0d 7 [ ] V Thu he iiu vlue required i 3V. EG30-II p. II-

27 EG30-II Nie i gle Mduled ye r ege igl, gle-duled igl: [ ] k p r M k τ dτ r M 0 The pre-deei iler h bdwidh WD where D i he requey devii ri d i he bdwidh he ege igl. Nie G Liier Diriir L eeiver Dedulr Ipu igl pwer he dedulr: [ ] Ipu ie pwer he dedulr: W W N bere he dedulr: N i W y p. II-5

28 EG30-II p. II-6 Nie i gle Mduled ye Le G he ipu he dedulr uh h i G θ The liier uppree y pliude vrii G, hu i gle duli, N i derived r ideri θ ly. σ σ σ θ r ll Q { } { } G i ] [ ; θ where T ilie he lyi he ie ly, we ue 0 Thu,

29 EG30-II p. II-7 Nie i gle Mduled ye θ r high ipu N, >>, >>, hu, θ G α Oupu ie r Liier: Thi peri i ju like pig hrugh diereir wih rer repe d d d α Oupu ie r Diriir egle DC er: j H α d H Thu, ider he reli pwer perl deiie: I he ipu ie i whie wih /, / / L α L

30 EG30-II p. II-8 Nie i gle Mduled ye Wih d, Thu, d H α d j H α r W Oupu igl r diriir: d d d α α Oupu ie pwer er L wih bdwidh : k k y L α Negleig he DC er, give k y k y α α Oupu N: k k y N α α

31 EG30-II p. II-9 Nie i gle Mduled ye k N I he ege igl i iuidl igle-e, i.e. d prdue requey devii, i 3 M igl: Diereiig, give 0 3 Q d k τ τ k Thu, k N β 3 3 N β 3 r M Ne: Whe β5, upu N M ye i 37.5 ie h bebd ye, bu he bdwidh M ye i bu ie h he bebd ye.

32 N i M & M ye EG30-II Uder he vrble dii i M, he duli ide i 00%, hu N M 3 r M: N M 3 β I hw h he upu igl--ie ri be de uh higher i M h i M by ireig he duli ide β. iree i β l iree he bdwidh h M ye prvide iprvee i igl--ie he epee iree i bdwidh. T relize y igl--ie iprvee i M ver M we u hve 3 β > β > Thi dii i ppriely he rii pi bewee rrwbd d widebd M. Nrrwbd M prvide igl--ie iprvee ver M. p. II-0

33 re-ephi d De-ephi i M ell: he pwer perl deiy he M diriir upu α d r W d -W/ 0 W/ Nie pwer i lrger higher requeie wihi he ege bdwidh. re-ephi: he high-requey pe i he ipu ege igl re ephized he rier bere he ie i irdued. De-ephi: he upu M dedulr, he ivere peri i perred de-ephize he high requey pe EG30-II p. II-

34 EG30-II p. II- re-ephi d De-ephi i M re-ephi iler De-ephi iler M rier M reeiver WGN upu H E H DE W W H H DE E < <, / ; DE E j K H j K H Eple: ipu upu C ipu upu r C α d d d Oupu ie pwer wihu de-ephi iler: Oupu ie pwer wih de-ephi iler: α d H d H E E d