Cac He Thong Khong Gian Thoi Gian

Download Cac He Thong Khong Gian Thoi Gian

Post on 28-Dec-2015

76 views

Category:

Documents

4 download

Embed Size (px)

TRANSCRIPT

<p>86</p> <p>Ti liuCc h thng khng gian thi gianGV: nguyn quc khngEmail: la_vn@yahoo.comTel:0912016024</p> <p> MC LC</p> <p>Chng 1. Cc khi nim c bn101.1Thng tin v tn hiu101.1.1Tn hiu tng t:101.1.2Tn hiu s:111.1.2.11.2.1 Tn hiu iu ch PAM121.1.2.2Tn hiu iu ch QAM:131.2Mi quan h gia tc bit v rng bng tn truyn dn141.2.1Cng thc Shannol141.2.2Quan h gia tc bit v s mc iu ch161.3Nhiu truyn dn v li bit.161.3.1Xy dng cng thc tnh t l li bit171.3.2V d tnh gi tr z cho mt s tn hiu191.4S khi ca h thng thng tin21Chng 2. Knh v khi phc knh VT232.1H thng mt anten thu pht - knh SISO232.2H thng nhiu anten thu pht - knh MIMO272.3c lng knh v khi phc d liu trong h thng thng tin312.3.1Khi nim312.3.2c lng knh trong h thng OFDM342.3.2.1c lng knh cho h thng SISO-OFDM352.3.2.2c lng knh cho h thng MIMO-OFDM36Chng 3. h thng MIMO403.1Phng php kt hp vi t l ti a MRC413.1.1Gii m trung bnh413.1.2MRC413.2H thng nhiu anten pht mt anten thu beamforming443.3Kh nhiu knh MIMO453.3.1MIMO with Zero Forcing Successive Interference Cancellation equalizer463.3.2MIMO with ZF SIC and optimal ordering493.4STBC523.4.1Trng hp hai pht mt thu523.4.2Trng hp 2 pht 2 thu - Alamuoiti 2x2553.5Tin m ha Precoding603.5.1Tin m ha cho h thng SISO613.5.2Tin m ha cho h thng MIMO623.5.3Tin m ha cho h thng MIMO-OFDM623.5.4Thit k bng m653.5.5La chn ma trn tin m ha663.6M ha khng gian-thi gian li STTC69Chng 4. OFDM v MIMO OFDM764.1OFDM764.2MIMO-OFDM794.3STBC-MIMO-OFDM804.4ALAMOUTI80 </p> <p>CC T VIT TT AMCAdaptive Modulation and CoddingM ha v iu ch thch ng</p> <p>AWGNAdditive White Gaussian NoiseNhiu trng (nhiu cng)</p> <p>A/DAnalog/DigitalChuyn i Tng t/S</p> <p>BERBit Error RatioT l bit li</p> <p>BS Base StationTrm thu pht gc</p> <p>CCICo-Channel InterferenceNhiu ng knh</p> <p>CDMACode Division Multiple Accessa truy nhp phn chia theo m</p> <p>CPCyclic PrefixTin t lp</p> <p>CSIChannel State InformationThng tin trng thi ca knh truyn</p> <p>CSMA/CDCarrier Sense Multiple Access with Collision Detecta truy nhp theo cm nhn sng mang c pht hin xung t</p> <p>DABDigital Audio BroadcastingPht thanh s</p> <p>DCADynamic Channel AllocationCp pht knh ng</p> <p>DSADynamic Subcarrier AllocationCp pht sng mang ng</p> <p>DLDownLinkng xung</p> <p>DSPDigital Signal ProcessingB x l tn hiu s</p> <p>DVB-TDigital Video Broadcasting TerrestrialTruyn hnh s mt t</p> <p>FDDFrequency Division DuplexSong cng phn chia theo tn s</p> <p>FDMFrequency Division MultiplexingGhp knh phn chia theo tn s</p> <p>FFTFast Fourier TransformChuyn i Furier nhanh</p> <p>GIGuard IntervalKhong bo v</p> <p>HIPERLAN/2High Performance Local Area Network type 2Mng cc b cht lng cao kiu 2</p> <p>IEEE Institute of Electrical and Electronic EngineersVin ca cc k s in v in t</p> <p>ISI Inter-Symbol InterferenceNhiu xuyn k t</p> <p>ICIInter-Channel InterferenceNhiu xuyn knh</p> <p>LSLeast squareBnh phng nh nht</p> <p>MAIMultiple Access InterferenceNhiu a truy nhp</p> <p>MIMOMultiple Input Multiple OutputH thng nhiu u vo nhiu u ra</p> <p>MISOMultiple Input Single OutputH thng nhiu u vo mt u ra</p> <p>MMSEMinimum Mean Square ErrorTrung bnh bnh phng ti thiu</p> <p>MSMobile StationTrm di ng</p> <p>OFDM Orthoganal Frequency Division MultiplexingGhp knh phn chia theo tn s trc giao</p> <p>OFDMA Orthoganal Frequency Division Multiple Accessa truy nhp phn chia theo tn s trc giao</p> <p>QAMQuadrature amplitude modulationiu ch bin cu phng</p> <p>RFRadio FrequencyTn s v tuyn</p> <p>SERSymbol Error RatioT l li k hiu</p> <p>SISOSingle Input Single OutputH thng mt u vo mt u ra</p> <p>SIMOSingle Input Multiple OutputH thng mt u vo nhiu u ra</p> <p>SNIRSignal to Interference-plus-Noise RatioT l tn hiu trn tp m cng nhiu</p> <p>SNRSignal to Noise RatioT l tn hiu trn tp m</p> <p>STCSpace-Time CodingM ha khng gian thi gian</p> <p>TDDTime Division DuplexSong cng phn chia theo thi gian</p> <p>TDMATime Division Multiple Accessa truy cp phn chia theo thi gian</p> <p>ULUp Linkng ln</p> <p>WifiWireless Fidelity Mng khng dy chun 802.11</p> <p>WFWater FillingPhng php nc</p> <p>WiMaxWorldwide Interoperability for Microwave AccessKh nng khai thc lin mng trn ton cu i vi truy cp vi ba</p> <p>ZFZero ForcingB lc p khng</p> <p>CC K HIU S DNG TRONG LUN N</p> <p>T s gia cng sut tn hiu trn cng sut nhiu (SNR)</p> <p>T s gia bn knh hai vng trong trong mt </p> <p> Tr truyn dn ca knh truyn</p> <p>Hiu qu ti s dng tn s</p> <p>Gi tr k d ca ma trn</p> <p>Bc ca tn hao trong khng gian t do</p> <p>Bin c gi tr thay i ty thuc vo mi trng biu din tn hao knh truyn</p> <p>2Biu din phng sai ca nhiu cng</p> <p>Lc di knh v tuyn tnh bng s mu tn hiu</p> <p>NFFTS lng sng mang con ca h thng OFDM</p> <p>Np di khong bo v mi k hiu OFDM</p> <p>MmsTng s thu bao MS trong ton h thng</p> <p>NbsTng s BS bng tng s trong ton h thng</p> <p>MTS lng anten pht</p> <p>MRS lng anten thu</p> <p>|.|Php tnh det ca ma trn</p> <p>||.||pTnh norm cp p ca ma trn</p> <p>(.)HChuyn v v ly lin hip phc cho ma trn hay mt bin</p> <p>Php nhn Kronecker cho ma trn</p> <p>Vec(H)Php tnh bin ma trn thnh vector</p> <p>Ht+Nghch o Moore-Penrose ca ma trn</p> <p>|M| i vi tp M th dng tnh s phn t ca tp M Biu thc cng dng tnh gi tr tuyt i</p> <p>CN(0,2)Biu din phn b chun c gi tr trung bnh bng khng v phng sai l 2</p> <p>Gio trnh mn cc h thng khng gian thi gianDnh cho sinh vin i hc v cao hc</p> <p>Hc phn gii thiu cc kin thc v lnh vc x l tn hiu kt hp ca min thi gian v khng gian bao gm: Cc vn v tnh cht knh truyn min khng gian v thi gian, m hnh h thng a ng ten pht v thu MIMO, m hnh h thng knh MIMO, cc phng php m ha khng gian v thi gian c bn (s m ha v gii m STBC ca Alamouti). S kt hp ca cng ngh MIMO vi cc k thut anten thng minh, k thut iu ch trcgiao OFDM. Cc ng dng ca k thut x l tn hiu khng gian v thi gian trong cc h thng thng tin tin tin. The course introduces the knowledge of the space-time signal processing which include: the charateristics of channels in the space and time domain, the MIMO system with multipe transmit and receive antenna, the methods of space and time encoding and decoding(Scheme of Alamouti STBC). The combination of MIMO with OFDM technology to enhance the channel capacity and spectrum efficiency. The combination of MIMO technology with smart antenna for avanced communication systems. Beamforming technique and antenna array design methods for MIMO sytem </p> <p>Cc khi nim c bn Mt s khi nim c bn n v tnh, db, mdb, v, Cts, disc Orthonormal PAM, 1-D 2-D signal Mc nng lng (Cng sut) trung bnh trn mt tn hiu Es,Eb,SNR, spectral efficiency Shannol theory Power limited regime, bandwidth limited regime, ultimated shannol limited BER,SER, Q function ca knh AWGN, v RL MAP, ML, MDD,. TDM,FDM,CDM,OFDM ng b c lng knh truyn nhm m bo ti u ha qu trnh thu pht thng tin. Thng tin v tn hiuThng tin l nhng ci m con ngi mun trao i vi nhau. Trong thc t thng tin trong cc h thng thng c chia ra lm ba dng thun tin cho vic x l v truyn dn l m thanh- hnh nh v thng tin d liu.Tn hiu truyn tin c th c chia thnh hai dng l tn hiu tng t v tn hiu s. Tn hiu tng t: nh ngha tn hiu tng t l tn hiu c bin thay i lin tc theo thi gian nh hnh v 1. X(t)t</p> <p>Hnh 11: Tn hiu tng tc trng cho tn hiu tng t bi hai tham s l bin ca tn hiu v di tn lm vic W=[fmin-fmax]. Bin ca tn hiu cho ta bit cng tn hiu l mnh hay yu, cn di tn lm vic cho ta bit tn hiu c truyn i tn s cao hay thp. Ngoi ra ta cn c tham s l rng bng tn ca tn hiu B=fmax-fmin. rng bng tn th hin lng thng tin m tn hiu mang l nhiu hay t, V d tn hiu m thanh ca con ngi c di tn t 16-20000hz. Tuy nhin tn hiu in thoi, l tn hiu m thanh khi ni vo my in thoi v c lc bt cc thnh phn tn s khng cn thit ch c di tn t 300 3400 hz. Tn hiu s: Tn hiu s trong thng tin c hiu nh l vic truyn i cc bit 0,1. truyn tn hiu s ngi ta s dng cc tn hiu ri rc, tn hiu ri rc l cc tn hiu c s thay i v pha, tn s hoc bin ca tn hiu mt cch khng lin tc. Hnh v</p> <p>(a) Tn hiu iu ch pha</p> <p>(b) Tn hiu iu ch tn s</p> <p>(c) Tn hiu iu ch bin </p> <p>Hnh 12: Mt s dng tn hiu iu ch sc trng cho tn hiu s bng hai tham s. Th nht l s mc ca tn hiu ti thiu bng 2. Ty thuc vo s mc iu ch tn hiu m mi mt tn hiu c th i din cho log2M bit. V tham s th 2 l tc bit. Trong thng tin, tn hiu iu ch theo tn s t c s dng do kh nng chng nhiu v iu ch nhiu mc km. Cc tn hiu iu ch pha v bin c s dng nhiu hn. biu din cc tn hiu v phng thc iu ch, ngi ta thng t chng trong mt khng gian tn hiu N chiu gi l chm sao. Thc t s lng chiu ca khng gian N thng bng 1 hoc 2. Trng hp N=1 ta c tn hiu iu ch PAM cn N=2 ta c tn hiu iu ch QAM. Tuy nhin iu ch PAM thc ra l trng hp c bit ca iu ch QAM khi gi tr cc tn hiu theo mt chiu l bng khng.</p> <p>1.2.1 Tn hiu iu ch PAMTrng hp ny tn hiu theo mt chiu. V d nh hnh v</p> <p>Hnh 13 (a)iu ch PAM 2 mc, (b)iu ch PAM 4 mc, (c)iu ch PAM 8 mc</p> <p>Trong iu ch PAM m bo xc sut li tn hiu l ng u nhau th khong cch gia cc tn hiu c t bng 2a. Nhn xt rng s bt iu ch trn mi mt tn hiu bng log2M l s mc iu ch. Trng hp iu ch 2 mc ta c log22=1 bit/1 mc, Trng hp iu ch 4 mc ta c log24=2 bit/1 mc, Trng hp iu ch 8 mc ta c log28=3 bit/1 mc, . T vic iu ch ny ta c khi nim tc tn hiu (baud). vb=1/log2M vb. </p> <p>Tham kho . Vi s iu ch M mc (M l s chn) -(M-1) -5, -3, -, +,3, 5,,(M-1). E[M-PAM]=(2/M)12+32++M2). (Cng thc tng qut tnh mc nng lng ca mt tn hiu: Es=22(M2-1)/3V d vi M=1, chun ha gi tr =1. Trng hp iu ch 2 mc E=2, M=2 iu ch 4 mc E=10,..i khi trong thng tin ta c th biu din nng lng ca mt bit bng thng s Eb. V mt tn hiu c th l mt hoc nhiu bit thng tin nn quan h gia Eb v Es lEb=Es/log2M(11)</p> <p>C/N vs. Eb/No </p> <p> Eb/No = C/N + 10Log(Symbol Rate/Bit Rate) Eb is the Energy in a bit - Determines Bit Error Rate (BER) Bit Rates &gt;= Symbol Rates Eb/No </p>