Binary Phase Shift Keying

Binary Phase Shift Keying6. Ti liu tham kho

Li m uTrong nhng nm qua, k thut vin thng c nhng bc tin vt bc. Nhiu k thut cng ngh mi ra i sau nhanh chng tr nn lc hu v c thay th bi nhng k thut tin b hn, c nhiu u im hn ngay sau Tuy vy, trong lnh vc o to v in t vin thng, vic nm vng cc kin thc c s v tn hiu ph ca cc phng thc iu ch c in (iu ch tng t AM, FM, PM hoc iu ch s ASK, FSK, PSK) l v cng quan trng.V vy, nhm 12 s trnh by v qu trnh thc hin mch iu ch 2-PSK (Binary Phase Shift Keying). y l mt phng php iu ch tn hiu s c s dng rng ri trong nhiu lnh vc (nh wireless LAN, Bluetooth) v tnh n gin.Ni dung ca bi bo co gm cc phn: L thuyt v 2-PSK M phng Matlab Qu trnh thi cng mch ca nhm.Nhm cm n thy PGS. TS. L Tin Thng truyn t nhng kin thc cn thit v phng php iu ch 2-PSK ni ring v cc phng php iu ch tn hiu ni chung nhm c th hon thnh tt project.Project c thc hin bng s n lc ht mnh ca nhm, nhng do kh nng c hn nn vn cn tn ti nhiu thiu st, mong thy gp v ch dy thm nhm c th lm tt hn trong cc project sau ny. Mt ln na nhm xin chn thnh cm n thy.Thnh vin nhm:Trn Thanh Kha51101541Nguyn Nht Nam41102145MC LC1L THUYT41.1nh ngha41.2Gin chm sao41.3Phng thc iu ch 2-PSK51.4Bng thng52M PHNG MATLAB62.1Matlab code62.2Matlab Simulink72.3Kt lun93THI CNG MCH103.1S nguyn l v cc linh kin cn thit103.2M phng mch bng Multisim123.3Th mch trn breadboard143.4Thc hin v mch trn Eagle183.5Thi cng mch in204KT QU T C225PH LC235.1Code Matlab235.2Slide thuyt trnh256TI LIU THAM KHO30

Binary Phase Shift Keying

4Trn Thanh Kha Nguyn Nht NamDANH MC HNH NHHnh 1.1 Tn hiu c iu ch Binary Phase Shift Keying4Hnh 1.2 Gin chm sao Binary Phase Shift Keying5Hnh 2.1 Nhp cc s liu u vo cho chng trnh Matlab6Hnh 2.2 Kt qu ca chng trnh Matlab6Hnh 2.3 S khi m phng Simulink-Matlab7Hnh 2.4 Kt qu m phng Simulink-sng mang8Hnh 2.5 Kt qu m phng Simulink-tn hiu s8Hnh 2.6 Kt qu m phng Simulink-tn hiu c iu ch9Hnh 3.1 S nguyn l mch iu ch Binary Phase Shift Keying10Hnh 3.2 S chn ca Opamp LM74110Hnh 3.3 S cc switch bn trong IC401611Hnh 3.4 S mch m phng Multisim12Hnh 3.5 M phng Multisim-Tn hiu sin vi pha 0o v pha 180o12Hnh 3.6 M phng Multisim-Tn hiu s cn c iu ch (xung vung)13Hnh 3.7 M phng Multisim-Tn hiu c iu ch Binary Phase Shift Keying13Hnh 3.8 1-Opamp 2-IC4016 3-IC4011 4-VK Arduino14Hnh 3.9 Ng vo v ng ra ca Opamp khi dng LM35815Hnh 3.10 Ng vo v ng ra ca Opamp khi dng LM74115Hnh 3.11 Sng mang v tn hiu c iu ch cng pha (bit u vo l bit 1)16Hnh 3.12 th X-Y khi sng mang v tn hiu c iu ch cng pha16Hnh 3.13 Sng mang v tn hiu c iu ch ngc pha (bit u vo l bit 0)17Hnh 3.14 th X-Y khi sng mang v tn hiu c iu ch ngc pha17Hnh 3.15 Schematic ca mch c v bng phn mm Eagle18Hnh 3.16 Layout v bng phn mm Eagle (lp trn)19Hnh 3.17 Layout v bng phn mm Eagle (lp di)19Hnh 3.18 Mch in do nhm thi cng (lp trn)20Hnh 3.19 Mch in do nhm thi cng (lp di)20Hnh 3.20 Sng mang v tn hiu c iu ch cng pha (bit u vo l 1)21Hnh 3.21 Sng mang v tn hiu c iu ch ngc pha (bit u vo l 0)21

L THUYTnh ngha2-PSK hay Binary Phase Shift Keying l mt phng php iu ch tn hiu s (Digital) vi sng mang l tn hiu tng t (Analog). Tn hiu s cn iu ch 2-PSK l tn hiu c mt baud (hay mt symbol) ch cha mt bit l 0 hoc 1. Tn hiu sau khi iu ch s c dng sng sin vi pha l 0o (tng ng vi bit 1) v sng sin vi pha 180o (tng ng vi bit 0), hoc cng c th ngc li (pha 0o vi bit 0 v pha 180o vi bit 1).Cng thc cho tn hiu c iu ch 2-PSK:(1.1)

Hnh 1.1 Tn hiu c iu ch Binary Phase Shift Keying

Gin chm saong vi nh ngha, gin chm sao ca 2-PSK ch gm 2 im c bin bng nhau v lch pha nhau 180o.

Hnh 1.2 Gin chm sao Binary Phase Shift Keying

Phng thc iu ch 2-PSKC nhiu phng php thc hin iu ch tn hiu 2-PSK, y nhm dng phng php l to ra mt tn hiu ngc pha vi sng mang. u ra s c mt b chn tn hiu. Khi tn hiu s u vo l bit 1, u ra s chn tn hiu sng mang. Khi tn hiu s u vo l bit 0, u ra s chn tn hiu ngc pha vi sng mang.

Bng thngTn hiu PSK c bng thng bng ng baud rate, m i vi 2-PSK th baud rate cng bng bit rate (do mt baud ch cha 1 bit). Do bng thng tn hiu 2-PSK cng chnh l s bit rate.Binary Phase Shift Keying1. L thuyt

M PHNG MATLABMatlab codeon code Matlab m phng qu trnh iu ch tn hiu theo phng php 2-PSK. Chng trnh s yu cu nhp chui bit cn iu ch v tn s ca sng mang. (xem ph lc 6.1)Chy on code, sau ta nhp gi tr ca chui bit cng nh tn s sng mang

Hnh 2.1 Nhp cc s liu u vo cho chng trnh Matlab

Chng trnh s to nn mt khung cha hai th: tn hiu s c iu ch v tn hiu qua iu ch

Hnh 2.2 Kt qu ca chng trnh MatlabMatlab SimulinkS dng Matlab Simulink thc hin s khi sau

Hnh 2.3 S khi m phng Simulink-MatlabThng s ca khi Sine Wave: Bin : 2 Phase: 0 rad Tn s gc: 25.1327 rad/sThng s ca khi Pulse Generator: Bin : 2 Chu k: 2s rng xung: 50%

KT QU NHN C T CC SCOPESng mang

Hnh 2.4 Kt qu m phng Simulink-sng mang

Tn hiu s

Hnh 2.5 Kt qu m phng Simulink-tn hiu sTn hiu c iu ch

Hnh 2.6 Kt qu m phng Simulink-tn hiu c iu ch

Kt lunKt qu cc dng sng thu c bi qu trnh m phng bng Matlab (Code v Simulink) u chnh xc vi l thuyt ca phng php iu ch 2-PSK.Binary Phase Shift Keying2. M phng Matlab

THI CNG MCHS nguyn l v cc linh kin cn thit

Hnh 3.1 S nguyn l mch iu ch Binary Phase Shift Keying

Ngun sin (sng mang) c pht bng in thoi di ng.Ngun pht tn hiu s l vi iu khin Arduino.Opamp LM741 c nhim v o pha sng sin u vo (mch khuch i o du vi h s khuch i l -1 do Ri=Rf=10k). S chn ca Opamp lM741:

Hnh 3.2 S chn ca Opamp LM741IC 4016 l mt IC switch, c s nh sau:

Hnh 3.3 S cc switch bn trong IC4016

Chn s 13 v chn s 5 l hai ng vo iu khin ca IC4016. Hai sng sin c pha 0o v 180o s c a vo chn s 1 v chn s 3, hai chn s 2 v 4 cng c ni vo ng ra. Khi bit c a vo l 1, chn s 5 ln mc in p cao, chn 13 xung mc in p thp (Do chn 13 ni vi 1 cng NOT), khi switch s 1 ngt v switch s 2 ng, tn hiu ng ra l sng sin c pha l 0o. Tng t khi bit vo l 0, switch s 1 ng v switch s 2 ngt, tn hiu ng ra l sng sin c pha 180o.

M phng mch bng MultisimM phng mch bng Multisim. Do bn Multisim 13 khng c IC4016, nhm s dng thay th bi IC4066 (c chc nng tng t IC4016).

Hnh 3.4 S mch m phng MultisimKT QU CA OSCILLOSCOPE 1

Hnh 3.5 M phng Multisim-Tn hiu sin vi pha 0o v pha 180oKT QU CA OSCILLOSCOPE 3

Hnh 3.6 M phng Multisim-Tn hiu s cn c iu ch (xung vung)KT QU CA OSCILLOSCOPE 2

Hnh 3.7 M phng Multisim-Tn hiu c iu ch Binary Phase Shift KeyingKt lun: Qu trnh m phng mch trn Multisim cho cc dng sng ng vi l thuyt ca iu ch 2-PSK.

Th mch trn breadboardCc link kin, thit b s dng trong qu trnh th mch: Opamp LM741 (ban u s dng Opamp LM358 nhng chuyn sang LM741 v cho dng tn hiu tt hn) Hai in tr 10k IC 4016 Cng NOT dng IC 4011 (thc cht l cng NAND) Cp ngun v xung bi vi iu khin Arduino Pht sng mang bng in thoi di ng Quan st tn hiu bng phn mm Soundcard OscilloscopeMch trn breadboard

Hnh 3.8 1-Opamp 2-IC4016 3-IC4011 4-VK Arduino

KT QU CC DNG SNG THU C

Hnh 3.9 Ng vo v ng ra ca Opamp khi dng LM358

Hnh 3.10 Ng vo v ng ra ca Opamp khi dng LM741

Hnh 3.11 Sng mang v tn hiu c iu ch cng pha (bit u vo l bit 1)

Hnh 3.12 th X-Y khi sng mang v tn hiu c iu ch cng pha

Hnh 3.13 Sng mang v tn hiu c iu ch ngc pha (bit u vo l bit 0)

Hnh 3.14 th X-Y khi sng mang v tn hiu c iu ch ngc pha

Kt lun: Vic s dng in thoi pht tn hiu sin, cng nh vic s dng oscilloscope trn my tnh (c chnh xc khng cao) lm cho cc dng sng quan st c khng c chnh xc lm. Tuy nhin v cn bn, mch thc hin c mc ch ca n, l to ra 2 dng sng ng ra c s o pha khi tn hiu s u vo c s o bit.

Thc hin v mch trn EagleSchematic

Hnh 3.15 Schematic ca mch c v bng phn mm Eagle

Layout

Hnh 3.16 Layout v bng phn mm Eagle (lp trn)

Hnh 3.17 Layout v bng phn mm Eagle (lp di)

Thi cng mch inSau 2 ln thi cng nhm hon thnh mch in tng i hon thin

Hnh 3.18 Mch in do nhm thi cng (lp trn)

Hnh 3.19 Mch in do nhm thi cng (lp di)

Kt qu o c trn mch in:

Hnh 3.20 Sng mang v tn hiu c iu ch cng pha (bit u vo l 1)

Hnh 3.21 Sng mang v tn hiu c iu ch ngc pha (bit u vo l 0)Binary Phase Shift Keying3. Thi cng mch

Kt lun: Kt qu thu c trn mch thc l ng vi yu cu iu ch 2-PSK v tng t vi kt qu thu c khi th vi breadboard.KT QU T C Nm c l thuyt phng php iu ch 2 - PSK M phng thnh cng l thuyt thng qua Matlab, Multisim Hon tt vic thi cng mch thc, cho c kt qu nh mong mun

Binary Phase Shift Keying5. Ti liu tham kho

PH LCCode Matlab% MATLAB Script for a Binary PSK with two Phases % Clear all variables and close all figuresclear all;close all;clc; % Enter bit streambit_stream=input('Nhap chuoi bit: '); % Phase for bit 1P1 = 0; % Phase for bit 0P2 = pi; % Frequency of Modulating Signalfc = input('Nhap tan so song mang: '); % Time for one bitt = 0: 0.01 : 1; % This time variable is just for plottime = []; PSK_signal = [];Digital_signal = []; for ii = 1: 1: length(bit_stream) % The PSK Signal PSK_signal = [PSK_signal (bit_stream(ii)==0)*sin(2*pi*fc*t + P2)+(bit_stream(ii)==1)*sin(2*pi*fc*t + P1)]; % The Original Digital Signal Digital_signal = [Digital_signal (bit_stream(ii)==0)*zeros(1,length(t)) + (bit_stream(ii)==1)*ones(1,length(t))]; time = [time t]; t = t + 1; end % Plot the Original Digital Signalsubplot(2,1,1);plot(time,Digital_signal,'r','LineWidth',2);xlabel('Time (bit period)');ylabel('Amplitude');title('Original Digital Signal');axis([0 time(end) -0.5 1.5]);grid on; % Plot the PSK Signalsubplot(2,1,2);plot(time,PSK_signal,'LineWidth',2);xlabel('Time (bit period)');ylabel('Amplitude');title('PSK Signal with two Phase Shifts');axis([0 time(end) -1.5 1.5]);grid on;

Slide thuyt trnh

Binary Phase Shift Keying5. Ph lc

TI LIU THAM KHO PGS. TS. L Tin Thng, X L S Tn Hiu v Wavelet PGS. TS. L Tin Thng, Slide bi ging iu Bin Tng T v S PGS. TS. V nh Thnh, Nguyn L Thng Tin Tng T v S A . B . Carlson, P. B. Crilly, J.C. Rutledge, "Communication Systems", third ed., McGraw-Hill Inc., New York, 2002, ISBN: 0-07-112175-7 Simon Haykin, Communication Systems, John Wilet & Son Inc., 2001, ISBN 0-471-17869-1 H.P.E.Stern and S. A. Mahmoud, Communication Systems, Analysis and design,Prentice Hall, 2004, ISBN: 0-13-121929-4. Behrous A. Forouzan, Data Communications and networking, Mc. Graw Hill, 2003, ISBN 007- 123241-9 Mt s sch khc v h thng thng tin