Maalin wacan.
Waxaan ku qaatay dhowrkii sano ee la soo dhaafay cilmi baarista iyo abuurista algorithms kala duwan oo loogu talagalay habaynta calaamadaha meel bannaan ee armaajooyinka anteenada la qabsiga, waxaanan sii wadaa in aan sidaas sameeyo iyada oo qayb ka ah shaqadayda hadda. Halkan waxaan jeclaan lahaa inaan ku wadaago aqoonta iyo xeeladaha aan nafteyda u ogaaday. Waxaan rajeynayaa in tani ay faa'iido u yeelan doonto dadka bilaabaya inay wax ka bartaan aaggan habaynta calaamadaha ama kuwa si fudud u xiisaynaya.
Waa maxay anteenada la qabsiga?
- Tani waa qaybo anteeno ah oo meel bannaan loo dhigay si uun. Qaab dhismeedka la fududeeyay ee isku xirka anteenada la qabsiga, oo aan tixgelin doono, ayaa lagu matali karaa qaabkan soo socda:
Qalabka anteenada la qabsiga ah waxaa badanaa loo yaqaan anteenooyinkooda "smart"). Maxaa ka dhigaya anteenada array "caqli leh" waa unugga farsamaynta calaamadaynta goobta iyo algorithms-yada lagu hirgeliyay dhexdeeda. Algorithms-yadani waxay falanqeeyaan calaamadda la helay oo waxay sameeyaan isku-dheellitirno miisaanno $inline$w_1…w_N$inline$, taasoo go'aamisa baaxadda iyo wejiga bilowga ee calaamadda shay kasta. Qaybinta baaxadda-wejiga la siiyay ayaa go'aamisa guud ahaan shabagga oo dhan. Awoodda lagu soo saari karo qaabka shucaaca ee qaabka loo baahan yahay oo lagu beddelo inta lagu jiro farsamaynta calaamaduhu waa mid ka mid ah sifooyinka ugu muhiimsan ee qalabyada anteenada la qabsiga, taas oo u oggolaanaysa xalinta dhibaatooyin badan oo kala duwan. . Laakiin marka hore wax walba.
Sidee loo sameeyaa qaabka shucaaca?
tilmaamaya awoodda ishaarada ee ka soo baxaysa jiho gaar ah. Si fudud, waxaan u qaadaneynaa in walxaha dhogorta ah ay yihiin isotropic, i.e. Mid kasta oo iyaga ka mid ah, awoodda signalka la sii daayay kuma xirna jihada. Kordhinta ama yaraynta awoodda ay ku sii daysay shabaggu jiho gaar ah ayaa la helay sababtoo ah Mowjadaha korantada ee ay soo saaraan walxo kala duwan oo ka mid ah xayndaabka anteenada. Habka faragelinta deggan ee mowjadaha elektaroonigga ah ayaa suurtagal ah oo keliya haddii ay jiraan , i.e. Farqiga wejiga ee calaamaduhu waa inuusan isbeddelin waqti ka dib. Fikrad ahaan, shay kasta oo ka mid ah xayndaabka anteenada waa inuu iftiimaa isla inta jeer ee side $inline$f_{0}$inline$. Si kastaba ha ahaatee, ficil ahaan waa in qofku la shaqeeyaa calaamadaha cidhiidhiga ah ee leh balaca xaddidan $ inline$Delta f << f_{0}$ inline$.
Dhammaan curiyayaasha AR ha ku sii daayaan calaamad isku mid ah $inline$x_n(t)=u(t)$inline$. Kadibna marka la joogo aqbalaha, signalka laga helay element n-th waxaa lagu matali karaa gudaha foomka:
$$muujin$$a_n(t) = u(t-tau_n)e^{i2pi f_0(t-tau_n)}$$muujin$$
halka $inline$tau_n$inline$ ay tahay daahitaanka fidinta ishaarada laga soo bilaabo curiyaha anteenada ilaa meesha laga helayo.
Calaamadaha noocan oo kale ah waa "quasi-harmonic", iyo si loo qanciyo xaaladda isku xirnaanta, waxaa lagama maarmaan ah in dib u dhigista ugu badan ee faafinta hirarka elektromagnetic ee u dhexeeya laba walxood ay aad uga yar tahay wakhtiga dabeecadda isbeddelka ee baqshadda calaamadda $ inline$ T$ line $, i.e. $inline$u(t-tau_n) ≈ u(t-tau_m)$line$. Haddaba, shuruudaha isku xidhnaanta ishaarada cidhiidhiga ah waxa loo qori karaa sidan soo socota:
$$muujin$$T≈frac{1}{Delta f}>>frac{D_{max}}{c}=max(tau_k-tau_m) $$muujin$$
halka $inline$D_{max}$inline$ ay tahay masaafada ugu badan ee u dhaxaysa curiyayaasha AR, iyo $inline$с$inline$ waa xawaaraha iftiinka.
Marka calaamada la helo, soo koobid isku xidhan ayaa si dhijitaal ah loogu sameeyaa unugga habaynta boosaska. Xaaladdan oo kale, qiimaha kakan ee calaamadda dhijitaalka ah ee soo saarista xanniban waxaa lagu go'aamiyaa odhaahda:
$$muujin$$y=sum_{n=1}^Nw_n^*x_n$$muujin$$
Way ku habboon tahay in lagu matalo tibaaxaha ugu dambeeya ee foomka N-cabbirka kakan vectors qaab matrix ah:
$$muujin$$y=(textbf{w},textbf{x})=textbf{w}^Htextbf{x}$$muujin$$
halkaas oo w и x waa tiirarka tiirarka, $inline$(.)^H$inline$ waa hawlgalka .
Matalaadda Vector ee calaamadaha waa mid ka mid ah kuwa aasaasiga ah marka la shaqeynayo arrays anteeno, sababtoo ah inta badan waxay kuu ogolaataa inaad iska ilaaliso xisaabaadka xisaabta ee dhibka badan. Intaa waxaa dheer, aqoonsiga calaamadda la helay waqti go'an oo leh vector inta badan waxay u ogolaataa qofku inuu ka soo baxo nidaamka dhabta ah ee dhabta ah oo uu fahmo waxa dhabta ah ee dhacaya marka loo eego aragtida joomatari.
Si aad u xisaabiso qaabka shucaaca ee xayndaabka anteenada, waxaad u baahan tahay inaad maskax ahaan iyo si isku xigta u "billowdo" set laga bilaabo dhammaan jihooyinka suurtagalka ah. Xaaladdan oo kale, qiyamka qaybaha vector x waxaa lagu matali karaa qaabkan soo socda:
$$display$$x_n=s_n=exp{-i(textbf{k}(phi,theta),textbf{r}_n)}$$muujin$$
halkaas oo k - , $inline$phi$inline$ iyo $line$theta$inline$ - и , oo tilmaamaysa jihada ay u socoto hirka diyaarada, $inline$textbf{r}_n$inline$ waa isku xidhka curiyaha anteenada, $inline$s_n$inline$ waa unug ka mid ah wejiga wejiga s mowjad diyaaradeed oo leh mowjadaha hirka k (Suugaanta Ingiriisiga, vector-ka wejiga waxaa loo yaqaan 'sterage vector). Ku-tiirsanaanta baaxadda labajibbaaran ee tirada y laga bilaabo $inline$phi$inline$ iyo $inline$theta$inline$ ayaa go'aamisa qaabka shucaaca ee diyaarinta anteenada ee soo dhawaynta isugeynta miisaanka w.
Astaamaha nidaamka shucaaca ee anteenada
Way ku habboon tahay in la barto sifooyinka guud ee qaabka shucaaca ee habab anteeno ah oo toosan oo toosan oo siman oo anteeno ah oo ku taal diyaaradda jiifka ah (ie, qaabku wuxuu ku xiran yahay kaliya xagasha azimuthal $ inline$ phi$ line $). Ku habboon labada dhinac ee aragtida: xisaabinta gorfaynta iyo bandhigga muuqaalka.
Aan u xisaabino DN-ga halbeegga culeyska miisaanka ($ khad $w_n=1, n = 1 ... N$inline$), iyadoo la raacayo sifaha habayn.
Xisaab halkan
Saadaasha mawjada vector ee dhidibka toosan: $inline$k_v=-frac{2pi}{lambda}sinphi$inline$
Isku xidhka toosan ee curiyaha anteenada leh index n: $inline$r_{nv}=(n-1)d$inline$
waa d - muddada diyaarinta anteenada (fogaanshaha u dhexeeya walxaha ku xiga), λ - dhererka hirarka. Dhammaan qaybaha kale ee vector r waxay le'eg yihiin eber.
Digniinta ay heshay xayndaabka anteenada waxa lagu duubay qaabkan soo socda:
$$muujin$$y=sum_{n=1}^{N}1 ⋅exp{i2pi nfrac{d}{lambda}sinphi}$$muujin$$
Aan ku dabaqno qaacidada и :
$$display$$y=frac{1-exp{i2pi Nfrac{d}{lambda}sinphi}}{1-exp{i2pi frac{d}{lambda}sinphi}}=frac{sin(pi frac{Nd}) {lambda}sinphi)}{sin(pi frac{d}{lambda}sinphi)}exp{ipi frac{d(N-1)}{lambda}sinphi}$$muujinta$$
Natiijo ahaan waxaan heleynaa:
$$display$$F(phi)=|y|^2=frac{sin^2(pi frac{Nd}{lambda}sinphi)}{sin^2(pi frac{d}{lambda}sinphi)} $ $muujin$$
Inta jeer ee qaabka shucaaca
Natiijadu waxay keentay qaabka shucaaca anteenada waa shaqo xilliyeedka ah ee seeska xagasha. Tani waxay ka dhigan tahay in qiimaha qaarkood ee saamiga d/λ waxay leedahay diffraction (dheeraad ah) maxima.
Qaabka shucaaca aan caadiga ahayn ee xayndaabka anteenada ee N = 5
Qaabka shucaaca caadiga ah ee xayndaabka anteenada ee N = 5 ee nidaamka isku xidhka dabada
Booska "diffraction detectors" si toos ah ayaa looga eegi karaa ee DN. Si kastaba ha ahaatee, waxaan isku dayi doonaa inaan fahanno halka ay ka yimaadeen jir ahaan iyo joomatari ahaan (ee meel N-cabbir ah).
Alaabada vector s waa jibbaaro kakan $inline$e^{iPsi n}$inline$, qiyamkooda waxaa lagu go'aamiyaa qiimaha xagasha guud $inline$Psi = 2pi frac{d}{lambda}sinphi$inline$. Haddii ay jiraan laba xaglo oo guud oo u dhiganta jihooyin kala duwan oo ay ka imanayso hirarka diyaaradda, kuwaas oo $inline$Psi_1 = Psi_2 + 2pi m$inline$, markaa tani waxay ka dhigan tahay laba shay:
- Jir ahaan: mawjada diyaaradeed ee hore ee ka imanaysa jihooyinkan waxay keenaysaa qaybinta baaxadda wejiga isku midka ah ee oscillations elektromagnetic ah oo ku saabsan walxaha diyaarsanaanta anteenada.
- Joometric ahaan: labadan jiho waa ay isku beegmaan.
Tilmaamaha imaatinka mawjada ee habkan la xidhiidha waa kuwo u dhigma marka loo eego dhinaca aragtida anteenada oo aan la kala saari karin midba midka kale.
Sida loo go'aamiyo gobolka xaglaha oo kaliya hal ugu badnaan ee DP had iyo jeer been abuurto? Aynu tan ku samayno agagaaraha azimuth eber anagoo tixgelinayna tixgalintan soo socota: baaxada isbedelka wejiga ee u dhexeeya labada walxood ee isku xiga waa inay ku jiraan inta u dhaxaysa $inline$-pi$inline$ ilaa $inline$pi$inline$.
$$muujin$$-pi<2pifrac{d}{lambda}sinphi
Xallinta sinnaan la'aantan, waxaan helnaa xaaladda gobolka gaar ahaan agagaarka eber:
$$muujin$$|sinphi|
Waxaa la arki karaa in xajmiga gobolka ee gaarka ah ee xagasha ay ku xiran tahay xiriirka d/λ. Hadday d = 0.5λ, ka dibna jihada kasta oo imaatinka calaamaduhu waa "qof", iyo gobolka gaar ahaaneed wuxuu daboolayaa xaglaha buuxa. Hadii d = 2.0λ, ka dibna jihooyinka 0, ± 30, ± 90 waa u dhigma. Lobes diffraction ayaa ka muuqda qaabka shucaaca.
Caadi ahaan, lobes diffraction ayaa la raadiyaa in la xakameeyo iyada oo la adeegsanayo walxaha anteenada jihada ah. Xaaladdan oo kale, qaabka shucaaca dhamaystiran ee xayndaabka anteenada ayaa ah sheyga qaabka hal element iyo iskudubarid walxo isotropic ah. Halbeegyada jaantuska hal element ayaa inta badan lagu xusaa iyadoo lagu saleynayo xaaladda gobolka ee aan mugdi ku jirin ee xayndaabka anteenada.
Ballaca laf-dhabarta
qaacidada injineernimada ee lagu qiyaaso ballaca laf-dhabarta nidaamka anteenada: $inline$Delta phi ≈ frac{lambda}{D}$inline$, halka D ay tahay cabbirka sifada anteenada. Qaaciddada waxaa loo isticmaalaa noocyo kala duwan oo anteenooyin ah, oo ay ku jiraan kuwa muraayadaha ah. Aynu tusno in ay sidoo kale ansax u tahay armaajooyinka anteenada.
Aynu ogaano ballaca laf-dhabarka weyn ee eberyada ugu horreeya ee qaabka agagaarka ugu sarreeya. Lambarka $inline$F(phi)$inline$ baaba'a marka $inline$sinphi=mfrac{lambda}{dN}$inline$. Eberkii hore waxay u dhigmaan m = ±1. $inline$frac{lambda}{dN}<<1$inline$ waxaan helnaa $inline$Delta phi = 2frac{lambda}{dN}$inline$.
Caadi ahaan, ballaca qaabka jiheynta anteenada waxaa lagu go'aamiyaa heerka nuska tamarta (-3 dB). Xaaladdan, isticmaal tibaaxaha:
$$muujin$$Delta phi≈0.88frac{lambda}{dN}$$muujin$$
Tusaale:
Ballaca laf-dhabarka weyn waxaa lagu xakameyn karaa iyada oo la dejinayo qiyamka baaxadda kala duwan ee isku-duwayaasha miisaanka ee anteenada. Aynu tixgelinno saddex qaybood oo kala ah:
- Qaybinta lebbiska baaxadda (miisaanka 1): $inline$w_n=1$ dhexda $.
- Qiimaha baaxadda leh ee hoos u dhacaya cidhifyada shabaggeedu (miisaanka 2): $inline$w_n=0.5+0.3cos(2pifrac{n-1}{N}-pifrac{N-1}{N})$line$
- Qiimaha baaxadda leh ee ku koraya cidhifyada shabaggeedii (miisaanka 3): $inline$w_n=0.5-0.3cos(2pifrac{n-1}{N}-pifrac{N-1}{N})$inline$
Shaxanku waxa uu muujinayaa natiijada shucaaca caadiga ah ee miisaanka logarithmic:
Isbeddellada soo socda ayaa laga heli karaa shaxanka: qaybinta baaxadda miisaanka isugeynta miisaanka oo hoos u dhacaya cidhifyada jeexjeexyada waxay keenaysaa ballaarinta laf-dhabarka ugu weyn ee qaabka, laakiin hoos u dhaca heerka laf-dhabarka. Qiimaha baaxadda leh ee ku sii kordhaya cidhifyada anteenada, liddi ku ah, waxay u horseedaan cidhiidhi galka laf-dhabarka iyo korodhka heerka xuubka dhinaca. Way ku habboon tahay in la tixgeliyo xaddididda kiisaska halkan:
- Baaxadda isugeynta miisaannada dhammaan walxaha marka laga reebo kuwa daran waxay la mid yihiin eber. Miisaanka xubnaha ugu dambeeya waxay la mid yihiin hal. Xaaladdan oo kale, xadhiggu wuxuu noqonayaa mid u dhigma laba-cunsur AR oo leh muddo D = (N-1)d. Ma adka in la qiyaaso ballaca tufaax weyn iyadoo la isticmaalayo caanaha kor lagu soo bandhigay. Xaaladdan oo kale, darbiyada dhinacyadu waxay isu rogi doonaan diffraction maxima waxayna la jaanqaadi doonaan ugu badnaan.
- Miisaanka curiyaha dhexe wuxuu la mid yahay hal, dhammaan kuwa kale waxay la mid yihiin eber. Xaaladdan oo kale, waxaan dhab ahaan helnay hal anteeno leh qaabka shucaaca isotropic.
Jihada ugu badan ee ugu weyn
Markaa, waxaanu eegnay sida aad u hagaajin karto ballaca xudunta weyn ee AP AP. Hadda aan aragno sida loo hago jihada. Aan xasuusano signalka la helay. Aan rabno ugu badnaan qaabka shucaaca inuu u eego jiho gaar ah $inline$phi_0$inline$. Taas macnaheedu waa in awoodda ugu badan laga helo jihadan. Jihadani waxa ay u dhigantaa wejiga wareega $inline$textbf{s}(phi_0)$inline$ in N-Meelaha vector-ka cabbirka, iyo awoodda la helay waxaa lagu qeexaa sida laba jibbaaran ee wax soo saarka scalar ee wejigan wejiga ah iyo vector ee isbarbardhigga miisaanka. w. Wax soo saarka scalar ee labada vector waa ugu badnaan marka ay jiraan , i.e. $inline$textbf{w}=beta textbf{s}(phi_0)$inline$, meesha β - arrin caadi ka dhigaysa. Sidaa darteed, haddii aan dooranno vector miisaan la mid ah vector wejiga jihada loo baahan yahay, waxaan u wareejin doonaa ugu badnaan qaabka shucaaca.
U fiirso arrimahan soo socda ee miisaanka tusaale ahaan: $inline$textbf{w}=textbf{s}(10°)$inline$
$$display$$w_n=exp{i2pifrac{d}{lambda}(n-1)sin(10pi/180)}$$muujin$$
Natiijo ahaan, waxaan helnaa qaabka shucaaca oo leh ugu badnaan ugu badnaan jihada 10 °.
Hadda waxaan codsanaa isku-dheellitirnaanta miisaanka, laakiin maaha soo-dhoweynta calaamadaha, laakiin gudbinta. Waxaa habboon in la tixgeliyo halkan marka la gudbinayo calaamad, jihada mawjada mawjada waxay u beddeshaa lidkeeda. Tani waxay ka dhigan tahay in curiyeyaasha soo dhawaynta iyo gudbinta waxay ku kala duwan yihiin calaamada jibbaarada, i.e. waxay isku xidhan yihiin isku xidhid adag. Natiijo ahaan, waxaan helnaa ugu badnaan qaabka shucaaca ee gudbinta jihada -10 °, taas oo aan ku habboonayn ugu badnaan qaabka shucaaca ee soo dhaweynta isku-dhafka miisaanka isku midka ah.Si loo saxo xaaladda, waxaa lagama maarmaan ah mari isku xidhka adag ee isku xidhayaasha miisaanka sidoo kale.
Tilmaamaha lagu sharraxay ee samaynta qaababka soo dhaweynta iyo gudbinta waa in had iyo jeer maskaxda lagu hayaa marka la shaqeynayo qalabyada anteenada.
Aynu ku ciyaarno qaabka shucaaca
Dhowr sare
Aynu dejinno hawsha samaynta laba maxima ugu weyn ee qaabka shucaaca ee jihada: -5 ° iyo 10 °. Si tan loo sameeyo, waxaanu dooranaynaa vector ahaan miisaan ahaan wadarta miisaanka wejiga ee jihooyinka u dhigma.
$$display$$textbf{w} = betatextbf{s}(10°)+(1-beta)textbf{s}(-5°)$$muujin$$
Iyadoo la hagaajinayo saamiga β Waxaad hagaajin kartaa saamiga u dhexeeya tufaaxyada waaweyn. Halkan mar kale way ku habboon tahay in la eego waxa ka dhacaya booska vector. Hadii β waa ka weyn yahay 0.5, ka dibna vector ee isbahaysiga miisaanka ayaa u dhow s(10°), haddii kale s(-5°). Markasta oo uu u dhawaado vector-ka miisaanku waxa uu u dhaw yahay mid ka mid ah wajiyada, way sii weynaataa badeecada scalar ee u dhiganta, oo markaa qiimaha u dhigma ugu badnaan DP.
Si kastaba ha noqotee, waxaa habboon in la tixgeliyo in labada tufaax ee waaweyni ay leeyihiin ballac xaddidan, iyo haddii aan rabno inaan ku dhejino laba jiho oo dhow, markaa caleemahani waxay ku biiri doonaan mid ka mid ah, oo u jihaysan jihada dhexe.
Hal ugu badnaan iyo eber
Hadda aynu isku dayno in aynu ku hagaajino habka shucaaca ugu badnaan jihada $inline$phi_1=10°$inline$ isla markaana aynu cabudhino calaamada ka imanaysa jihada $inline$phi_2=-5°$inline$. Si tan loo sameeyo, waxaad u baahan tahay inaad dejiso eber DN xagasha u dhiganta. Waxaad sidan u samayn kartaa sidan:
$$muujin$$textbf{w}=textbf{s}_1-frac{textbf{s}_2^Htextbf{s}_1}{N}textbf{s}_2$$muujin$$
halka $inline$textbf{s}_1 = textbf{s}(10°)$inline$, iyo $inline$textbf{s}_2 = textbf{s}(-5°)$inline$.
Macnaha joomatari ee doorashada vector miisaanku waa sida soo socota. Waxaan rabnaa vector-kan w lahaa saadaasha ugu badnaan dulsaar $inline$textbf{s}_1$inline$ oo isla mar ahaantaana orthogonal u ahaa vector $inline$textbf{s}_2$inline$. Vector $inline$textbf{s}_1$inline$ waxa loo matali karaa laba erey: collinear vector $inline$textbf{s}_2$inline$ iyo vector orthogonal $inline$textbf{s}_2$inline$. Si loo qanciyo bayaanka dhibaatada, waxaa lagama maarmaan ah in la doorto qaybta labaad sida vector of coefficients miisaanka w. Qaybta collinear waxa lagu xisaabin karaa iyadoo la saadaaliyo vector $inline$textbf{s}_1$inline$ duleelka caadiga ah $inline$frac{textbf{s}_2}{sqrt{N}}$inline$ iyadoo la isticmaalayo sheyga scalar.
$$display$$textbf{s}_{1||}=frac{textbf{s}_2}{sqrt{N}}frac{textbf{s}_2^Htextbf{s}_1}{sqrt{N}} $$muujin$$
Sidaas awgeed, ka-goynta qaybteeda collinear-ka ah ee asalka ah ee vector $inline$textbf{s}_1$inline$, waxaanu helnaa vector-ka miisaanka loo baahan yahay.
Qoraalo dheeraad ah
- Meel kasta oo kor ku xusan, waxaan meesha ka saaray arrinta caadiga ah ee vector miisaanka, i.e. dhererkeeda. Sidaa daraadeed, caadiga ah ee vector-ka culeyska ma saameynayo sifooyinka anteenada qaabka shucaaca sunta: jihada ugu badan ee ugu weyn, ballaca laf-dhabarka, iwm. Waxa kale oo la tusi karaa in caadadani aanay saamayn ku yeelanayn SNR marka la soo saaro qaybta farsamaynta boosaska. Marka tan la eego, marka la tixgelinayo algorithms-ka habaynta calaamadaha goobta, waxaan caadi ahaan aqbalnaa halbeegga caadiga ah ee vector miisaanka, i.e. $inline$textbf{w}^Htextbf{w}=1$inline$
- Suurtagalnimada samaynta qaabka isku xidhka anteenada waxaa lagu go'aamiyaa tirada curiyeyaasha N. Cunsuriyada badan, ayaa sii ballaaranaya fursadaha. Heerarka badan ee xorriyadda marka la fulinayo habaynta culeyska goobta, fursadaha badan ee sida loo "maroojinayo" vector culeyska ee booska N-cabbirka.
- Marka la helo qaababka shucaaca, xayndaabka anteenadu ma jiro jir ahaan, waxaanas oo dhan waxay ku jiraan "male-awaalka" cutubka xisaabinta ee socodsiiya calaamadaha. Tani waxay ka dhigan tahay in isla mar ahaantaana ay suurtogal tahay in la sameeyo qaabab dhowr ah oo si madaxbannaan loo farsameeyo calaamadaha ka imanaya jihooyin kala duwan. Xaaladda gudbinta, wax walba waa xoogaa ka sii dhib badan, laakiin sidoo kale waa suurtogal in la sameeyo dhowr DNs si loo gudbiyo xogaha kala duwan. Tignoolajiyadan hababka isgaarsiinta waxaa loo yaqaan .
- Adigoo isticmaalaya koodka matlab ee la soo bandhigay, waxaad la ciyaari kartaa laftaada DN-ga
Code% antenna array settings N = 10; % number of elements d = 0.5; % period of antenna array wLength = 1; % wavelength mode = 'receiver'; % receiver or transmitter % weights of antenna array w = ones(N,1); % w = 0.5 + 0.3*cos(2*pi*((0:N-1)-0.5*(N-1))/N).'; % w = 0.5 - 0.3*cos(2*pi*((0:N-1)-0.5*(N-1))/N).'; % w = exp(2i*pi*d/wLength*sin(10/180*pi)*(0:N-1)).'; % b = 0.5; w = b*exp(2i*pi*d/wLength*sin(+10/180*pi)*(0:N-1)).' + (1-b)*exp(2i*pi*d/wLength*sin(-5/180*pi)*(0:N-1)).'; % b = 0.5; w = b*exp(2i*pi*d/wLength*sin(+3/180*pi)*(0:N-1)).' + (1-b)*exp(2i*pi*d/wLength*sin(-3/180*pi)*(0:N-1)).'; % s1 = exp(2i*pi*d/wLength*sin(10/180*pi)*(0:N-1)).'; % s2 = exp(2i*pi*d/wLength*sin(-5/180*pi)*(0:N-1)).'; % w = s1 - (1/N)*s2*s2'*s1; % w = s1; % normalize weights w = w./sqrt(sum(abs(w).^2)); % set of angle values to calculate pattern angGrid_deg = (-90:0.5:90); % convert degree to radian angGrid = angGrid_deg * pi / 180; % calculate set of steerage vectors for angle grid switch (mode) case 'receiver' s = exp(2i*pi*d/wLength*bsxfun(@times,(0:N-1)',sin(angGrid))); case 'transmitter' s = exp(-2i*pi*d/wLength*bsxfun(@times,(0:N-1)',sin(angGrid))); end % calculate pattern y = (abs(w'*s)).^2; %linear scale plot(angGrid_deg,y/max(y)); grid on; xlim([-90 90]); % log scale % plot(angGrid_deg,10*log10(y/max(y))); % grid on; % xlim([-90 90]);
Dhibaato noocee ah ayaa lagu xalin karaa iyadoo la isticmaalayo anteenada la qabsiga?
Soo dhawaynta ugu fican ee calaamad aan la garanaynHaddii jihada imaatinka calaamaduhu aan la garanayn (iyo haddii kanaalka isgaarsiintu uu yahay multipath, guud ahaan waxaa jira dhowr jihooyin), ka dib marka la falanqeeyo calaamada ay heshay xayndaabka anteenada, waxaa suurtagal ah in la sameeyo vector miisaanka ugu fiican. w si SNR ee wax-soo-saarka unugga farsamaynta boosku uu u ahaado ugu badnaan.
Soo dhawaynta isha ugu fiicnayd ee ka soo horjeeda buuqa asalkaHalkan dhibaatadu waxay u taagan tahay sida soo socota: xuduudaha booska ee calaamadda faa'iidada leh ee la filayo waa la yaqaan, laakiin waxaa jira ilo faragalin ah oo deegaanka dibadda ah. Waa lagama maarmaan in la kordhiyo SINR ee wax soo saarka AP, iyadoo la yareynayo saameynta faragelinta ee soo dhaweynta calaamadaha sida ugu macquulsan.
U gudbinta isha ugu wanaagsan ee isticmaalahaDhibaatadan waxaa lagu xalliyaa hababka isgaarsiinta mobaylada (4G, 5G), iyo sidoo kale Wi-Fi. Macnuhu waa mid fudud: iyada oo la kaashanayo calaamadaha duuliyaha gaarka ah ee kanaalka jawaab-celinta isticmaalaha, sifooyinka isgaadhsiinta ee kanaalka isgaadhsiinta ayaa la qiimeeyaa, iyada oo ku saleysan, vector of coefficients miisaanka oo u fiican gudbinta ayaa la doortaa.
Isku dhufashada meel bannaan ee qulqulka xogtaNidaamyada anteenada ee la qabsiga ah waxay u oggolaanayaan gudbinta xogta dhowr isticmaale isla waqti isku mid ah isla inta jeer ee isku mid ah, iyaga oo u sameynaya qaab shakhsi ah mid kasta oo iyaga ka mid ah. Tignoolajiyadan waxaa loo yaqaan MU-MIMO waxaana hadda si firfircoon looga hirgeliyaa (iyo meel horeba) nidaamyada isgaarsiinta. Suurtagalnimada isku dhufashada boosaska waxaa lagu bixiyaa, tusaale ahaan, 4G LTE heerka isgaarsiinta mobaylka, IEEE802.11ay heerka Wi-Fi, iyo 5G heerarka isgaarsiinta mobaylka.
Qalabka anteenada Virtual ee raadaarkaNidaamyada anteenooyinka dhijitaalka ah ayaa suurtogal ka dhigaya, iyadoo la adeegsanayo dhowr walxood oo anteeno gudbinaysa, si ay u sameeyaan anteeno dalwad ah oo cabbirro weyn leh si loo habeeyo calaamadaha. Shabakadda casriga ah waxay leedahay dhammaan sifooyinka midda dhabta ah, laakiin waxay u baahan tahay qalab yar si loo hirgeliyo.
Qiyaasta qiyaasaha ilaha shucaacaQalabka anteenada ee la qabsiga ah ayaa oggolaanaya xallinta dhibaatada qiyaasidda tirada, awoodda, Ilaha qiiqa raadiyaha, la sameeyo xiriir xisaabeed oo u dhexeeya calaamadaha ilo kala duwan. Faa'iidada ugu weyn ee isku xidhka anteenada la qabsiga ee arrintani waa awoodda aad u xallinaysa ilaha shucaaca ee dhow. Ilaha, masaafada xaglaha ah ee u dhaxaysa taas oo ka yar ballaca laf-dhabarka weyn ee qaabka shucaaca anteenada (). Tani waxay inta badan suurtagal tahay sababtoo ah matalaadda vector ee calaamadda, qaabka calaamadda ee caanka ah, iyo sidoo kale qalabka xisaabta toosan.
Waad ku mahadsantahay dareenkaaga.
Source: www.habr.com