Communication Systems, 5e

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1 Communiaion Syem, 5e Chape 4: Banpa Digial anmiion A. Bue Calon Paul B. Cilly he MGaw-Hill Companie

2 Chape 4: Banpa Digial anmiion Digial CW moulaion Coheen inay yem Nonoheen inay yem Quaaue-aie an M-ay yem Ohogonal equeny iviion muliplexing elli-oe moulaion he MGaw-Hill Companie

3 Binay moulae waveom a) ASK ) FSK ) PSK ) DSB wih aean pule haping 3

4 Ampliue Moulaion Meho Ampliue hi eying (ASK) i igial AM x A a o p On-O Keying ue an o a M-ASK ue n value a eihe,.,.,, M- o.5,.5,.5,, M-+.5 Quaaue AM ue eal an omplex ymol x A ai o aq in p 4-QAM an 4-PSK ae equivalen Reee o a onellaion moulaion eaue he ymol an e epeene a poin in a wo-imenional Real v. Imaginay o In-Phae v. Quaaue-Phae plo, ha i poin a (ai, aq ). D D 4

5 5 Ampliue Shi Keying (ASK) Digial Symol Ampliue Moulaion On-O Keying (OOK) Auo-oelaion Aveage Powe o A A o 4 o OOK OOK A A P R P R P P p p A

6 6 Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. ASK Powe Speum A A S vv 4 in 4 vv vv S S G 4 Figue 4.-

7 ASK MALAB Simulaion Symol Sequen in ime Symol Sequene Ciula Auo-oelaion.5-5 Ampliue -.5 Magniue (B) ime x -5 OOK Demoulaion ye Diagam -5 3 Fequeny x 8 Symol Sequene Ciula Auo-oelaion - Ampliue.5.5 Magniue (B) ime x Fequeny x 7 7

8 8 Phae Moulaion Meho Phae hi eying (PSK) i igial PM Poin on a uni ile o a onellaion plo Fequeny hi eying (FSK) i igial FM D p A x o D p a A x o

9 PSK ignal onellaion Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. (a) M=4 () M=8: Figue 4.-5 hi QAM, oae y pi/4 o 4-PSK 9

10 Phae Shi Keying Binay Phae Shi Keying A o A o A o A o M-ay PSK o MPSK A I Q o M, o o M, o,in, o o M M M

11 Binay PSK Signal Symol Auooelaion A o A o A o A o * A o Co Coelaion (he einiion o anipoal) * A o R R R

12 M-PSK An M-ay Signal M omplex ymol Quaaue ( poile epeenaion) Auo-oelaion, ingle ymol Peio Aveage Powe, Ampliue o negy M o o, M o A * o A o PSK A A P M o o, M,in M o,q I p A

13 BPSK Powe Speum Fom Chape S vv Baean o LPF analyi RF Analyi P m Pn n a, a A n a n G S vv a A in n P p e S S vv vv in 3

14 BSK Powe Speum G S vv A in S S 4 vv vv Simila o OOK: no aie, geae magniue Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. 4

15 BPSK MALAB Simulaion Ampliue ime x -6 BPSK Demoulaion ye Diagam.5 Magniue (B) Fequeny x Ampliue Magniue (B) ime x Fequeny x 7

16 Digial Fequeny Moulaion Fequeny Shi Keying (FSK) Coninuou Phae FSK (CPFSK) 6

17 Fequeny Shi Keying Binay FSK A o A o M-ay FSK o MFSK A o, o o M a Deie Coniion m, o m an inege ep S ep 7

18 M-FSK An M-ay Signal M omplex ymol A o, o o M a Deie Coniion (nomally) m, o m an inege ep Cooelaion * A o ep a ep Can mae expee value zeo ep Auooelaion * A o a ep 8

19 BFSK Signal Symol Auooelaion A o A o * A o Co Coelaion (ohogonal o x x=) * A o o * A o 9

20 BFSK Quaaue Repeenaion () A o a a A o o a A in in a he ign em o o i eome A o o a A in in A o o a A in in A o o a A in in I, Q o, a in Co em i onan, Sin em hange ign wih i value

21 BFSK Quaaue Repeenaion () a Q I in, o, 4 q i lp Q G G G he aean peum G lp in in 4 Q o 4 Q o 4 4 q i lp G G G

22 Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. Powe peum o BFSK o 4 4 vv S Figue 4.-8

23 Speum o M-FSK A one wih equal paing ae equie, MFSK equie aiional anwih o aiional ymol one. he anwih mu gow a a muliple o M, wheea o M-PSK he anwih i ae on he ymol peio. M-FSK i inheenly wiean moulaion. Moe i pe ymol equie moe anwih Alway iue o i-pe-ymol, anwih, an SNR ( /N ) 3

24 4 Speial Veion o FSK Coninuou Phae FSK (CPFSK) he phae i oninuou a he aniion eween i. hi i mo eaily aomplihe i he phae i π o a muliple o π a he a an en o eah i peio. x A x o a a a a a x j j,,,

25 Binay CPFSK he inay veion o CPFSK i alle Minimum-Shi Keying (MSK) Alo alle a FSK Capale o uing an / anwih! 5

26 6 MSK Baean Fequeny an phae (hioy) moulaion Q I, p a x i o p a x q in o o n even o m,,

27 Illuaion o MSK. Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. (a) phae pah () i an q waveom: Figue 4.- MSK inlue he phae hioy wih he equeny lope in ime o he new i. heeoe he phae plo in ime an appea a hown, wih he oeponing quaaue omponen. 7

28 Minimum Shi Keying (MSK) Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. MSK powe peum: Figue 4.-9 Ue.5 in BFSK Sim 8

29 Coheen Binay Deeion All he imulaion have ue oheen mahe eeive ignal eeion A goo a i an ge! 9

30 Opimum inay eeion Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. (a) paallel mahe ile () oelaion eeo: Figue

31 Coniional PDF Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. Figue 4.- 3

32 Banpa inay eeive Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. Figue 4.- Uing upepoiion o he paallel mahe ile, he BPF i he ieene o he wo ile. h h h BPF hi eul in an opimal inay eeo 3

33 h OOK BPSK BPF BFSK h h h h BPF h BPF Binay Reeive h h K K h K o h h h K o BPF h BPF h h K K o o h BPF in in 33

34 Coelaion eeive o OOK o BPSK Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. Figue 4.-4 Sine oh opimal ile oni o oine waveom, mix an inegae inea o ile an opimally ample. Noe ha he inegao an e a eangula winow ile ha i opimally ample. (Povie unionaliy nea ynhonizaion a well.) 34

35 35 Opimal Paallel Mahe File Reeive o Analyi valuaing he expee value max N z z max N N z z he o oelaion oeiien!

36 Opimal Paallel Mahe File Reeive o Analyi OOK z z N max PSK z z N max FSK z z N max Ohogonal v. Anipoal peomane 36

37 Genealize Poailiy o o Uing he opimal BPF ile an ampling o eah ymol, he elaionhip will e ae on: z z N N max he BR i hen ae on P e z z Q Q N heeoe piing aiay ymol i poile, u he ymol oelaion oeiien will ive he BR peomane. 37

38 Genealize FSK A o A o A o A o o o hee ae muliple ohogonal one epaaion. he oelaion oeiien an go negaive! he minimum ou a appoximaely in(.) = -.66 exp exp i i exp i i exp i i in in 4 4 in 38

39 Nonoheen Binay Syem Synhonou oheen eeive an e vey iiul o eign. Can nonoheen yem e moe eaily eigne wihou giving up igniian BR peomane? Fo a - B /N o peomane lo, YS! 39

40 Nonoheen OOK eeive Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. Figue 4.3- Uing an envelope eeo, he noie p o a zeo ymol eome Riian an i non-longe Gauian. he noie p o a one ymol emain Gauian 4

41 4 Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. Figue Coniional PDF o nonoheen OOK op A V op e op e V P V P exp N P e exp N P P P P e e e e

42 Nonoheen eeion o inay FSK Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. Figue

43 Nonoheen FSK Qualiaive ommen Uing envelope eeo on eah ymol oupu, he Riian eo iiuion ee he z eeion aii. P e exp N 43

44 Binay eo poailiy uve Copyigh he MGaw-Hill Companie, In. Pemiion equie o epouion o iplay. (a) oheen BPSK () DPSK () oheen OOK o FSK () nonoheen FSK (e) nonoheen OOK: Figue BR Simulaion o BPSK an BFSK - - BR BPSK imulaion BPSK (heoeial) BFSK imulaion BFSK (heoeial) /N o (B) 44

ECE 6640 Digital Communications

ECE 6640 Digital Communications C 664 Digial Communiaion D. Badley J. Bazuin ian Poeo Depamen o leial and Compue ngineeing College o ngineeing and pplied Siene Chape 4 4. Bandpa Modulaion and Demodulaion/Deeion.. Why Modulae?. Digial