Nako e monate ea letsatsi.
Ke qetile lilemo tse 'maloa tse fetileng ke etsa lipatlisiso le ho theha li-algorithms tse fapaneng bakeng sa ts'ebetso ea matšoao a sebaka ka har'a li-antenna tse feto-fetohang,' me ke tsoela pele ho etsa joalo e le karolo ea mosebetsi oa ka oa hajoale. Mona ke rata ho arolelana tsebo le maqheka ao ke iphumanetseng ona. Ke tšepa hore sena se tla ba molemo ho batho ba qalang ho ithuta sebaka sena sa ts'ebetso ea matšoao kapa ba thahasellang feela.
Lethathamo la li-antenna tse feto-fetohang ke eng?
- ena ke sehlopha sa li-antenna tse behiloeng sebakeng ka tsela e itseng. Sebopeho se nolofalitsoeng sa li-antenna tse feto-fetohang, tseo re tla li tšohla, li ka emeloa ka mokhoa o latelang:
Li-antenna tse ikamahanyang le maemo hangata li bitsoa "smart" antennas (). Se etsang hore "antenna" e be "bohlale" ke yuniti ea ts'ebetso ea matšoao a sebaka le li-algorithms tse kentsoeng ho eona. Li-algorithms tsena li sekaseka lets'oao le amohetsoeng mme li theha sehlopha sa li-coefficients tsa boima ba $ inline$w_1…w_N$inline$, tse khethollang boholo le mohato oa pele oa lets'oao bakeng sa element ka 'ngoe. Kabo e fanoeng ea amplitude-phase e etsa qeto letlapa lohle ka kakaretso. Bokhoni ba ho kopanya sebopeho sa mahlaseli a sebopeho se hlokahalang le ho se fetola nakong ea ts'ebetso ea lets'oao ke e 'ngoe ea likarolo tsa mantlha tsa li-antenna tse feto-fetohang, tse lumellang ho rarolla mathata a mangata. . Empa lintho tsa pele pele.
Mokhoa oa mahlaseli o thehoa joang?
e khetholla matla a lets'oao le hlahisoang ka nqa e itseng. Bakeng sa ho nolofatsa, re nka hore likarolo tsa lattice ke isotropic, i.e. bakeng sa e 'ngoe le e' ngoe ea tsona, matla a pontšo e hlahisitsoeng ha a itšetlehe ka tataiso. Ho phahamisa kapa ho fokotsa matla a hlahisoang ke grating ka tsela e itseng e fumanoa ka lebaka la Maqhubu a motlakase a hlahisoang ke likarolo tse fapaneng tsa sehlopha sa antenna. Mokhoa o tsitsitseng oa ho kena-kenana le maqhubu a motlakase oa motlakase o ka khoneha ha feela , ke. phapang ea mekhahlelo ea lipontšo ha ea lokela ho fetoha ha nako e ntse e ea. Haele hantle, karolo e 'ngoe le e' ngoe ea sehlopha sa antenna e lokela ho khanya ka lebelo le ts'oanang la mofani oa thepa $inline$f_{0}$inline$. Leha ho le joalo, ts'ebetsong motho o tlameha ho sebetsa ka mats'oao a narrowband a nang le sekhahla sa bophara bo lekantsoeng $inline$Delta f <<f_{0}$inline$.
Lumella likarolo tsohle tsa AR ho hlahisa lets'oao le ts'oanang le $inline$x_n(t)=u(t)$inline$. Ebe joale ho moamoheli, lets'oao le amohetsoeng ho tsoa ho karolo ea n-th le ka emeloa ho sebopeho:
$$pontsho$$a_n(t) = u(t-tau_n)e^{i2pi f_0(t-tau_n)}$$pontsho$$
moo $inline$tau_n$inline$ e leng tieho ea phatlalatso ea lets'oao ho tloha karolong ea antenna ho ea sebakeng sa kamohelo.
Pontšo e joalo ke "quasi-harmonic", le ho khotsofatsa boemo ba momahano, hoa hlokahala hore ho lieha ho hoholo ha ho phatlalatsoa ha maqhubu a motlakase pakeng tsa likarolo leha e le life tse peli ho fokotsehile haholo ho feta nako ea phetoho ea enfelopo ea pontšo $ inline $ T $ inline $, i.e. $inline$u(t-tau_n) ≈ u(t-tau_m)$inline$. Kahoo, boemo ba ho hokahana ha lets'oao la narrowband le ka ngoloa ka tsela e latelang:
$$display$$T≈frac{1}{Delta f}>>frac{D_{max}}{c}=max(tau_k-tau_m) $$display$$
moo $inline$D_{max}$inline$ e leng sebaka se seholo pakeng tsa likarolo tsa AR, le $inline$с$inline$ ke lebelo la khanya.
Ha lets'oao le amoheloa, ho kopanngoa ha kakaretso ho etsoa ka dijithale sebakeng sa ts'ebetso ea sebaka. Tabeng ena, boleng bo rarahaneng ba lets'oao la dijithale tlhahisong ea boloko bona bo khethoa ke poleloana e reng:
$$pontsho$$y=kakaretso_{n=1}^Nw_n^*x_n$$pontsho$$
Ho bonolo haholoanyane ho emela polelo ea ho qetela ka foromo Li-vector tse rarahaneng tsa N-dimensional ka sebopeho sa matrix:
$$pontsho$$y=(textbf{w},textbf{x})=textbf{w}^Htextbf{x}$$display$$
moo w и x ke li-vector tsa kholomo, 'me $inline$(.)^H$inline$ ke ts'ebetso .
Vector e emelang lipontšo ke e 'ngoe ea lintho tsa motheo ha u sebetsa ka lihlopha tsa antenna, hobane hangata e u lumella ho qoba lipalo tse boima tsa lipalo. Ntle le moo, ho tsebahatsa lets'oao le amohetsoeng ka nako e itseng le vector hangata ho lumella motho hore a se ke a tsoa tsamaisong ea 'mele ea' mele le ho utloisisa se etsahalang hantle ho latela pono ea geometry.
Ho bala sebopeho sa mahlaseli a sehlopha sa antenna, o hloka ho "hlahisa" sete ea kelello le ka tatellano. ho tsoa nqa tsohle tse ka khonehang. Tabeng ena, boleng ba likarolo tsa vector x e ka emeloa ka mokhoa o latelang:
$$display$$x_n=s_n=exp{-i(textbf{k}(phi,theta),textbf{r}_n)}$$display$$
moo k - , $inline$phi$inline$ le $inline$theta$inline$ - и , e khethollang tataiso ea ho fihla ha leqhubu la sefofane, $inline$textbf{r}_n$inline$ ke khokahanyo ea karolo ea antenna, $inline$s_n$inline$ ke karolo ea vector e tsoelang pele. s leqhubu la sefofane le nang le vector ea maqhubu k (lingoliloeng tsa Senyesemane vector ea mekhahlelo e bitsoa steerage vector). Ho its'etleha ka boholo ba squared amplitude ea bongata y ho tloha ho $inline$phi$inline$ le $inline$theta$inline$ e etsa qeto ea sebopeho sa mahlaseli a li-antenna bakeng sa kamohelo bakeng sa vector e fanoeng ea li-coefficients tsa boima. w.
Likarolo tsa sebopeho sa mahlaseli a li-antenna
Ho bonolo ho ithuta litšobotsi tse akaretsang tsa sebopeho sa mahlaseli a li-antenna ka har'a sehlopha sa li-antenna tse lekanang sefofaneng se otlolohileng (ke hore, mohlala o itšetlehile feela ka angle ea azimuthal $inline$phi$inline$). E bonolo ho tsoa lintlheng tse peli: lipalo tsa tlhahlobo le tlhahiso ea pono.
Ha re bale DN bakeng sa vector ea boima ba yuniti ($inline$w_n=1, n = 1 ... N$inline$), ho latela tse hlalositsoeng atamela.
Lipalo mona
Khakanyo ea vector ea wave holima axis e otlolohileng: $inline$k_v=-frac{2pi}{lambda}sinphi$inline$
Khokahano e otlolohileng ea lenaka le index n: $inline$r_{nv}=(n-1)d$inline$
ke d - nako ea li-antenna (sebaka se pakeng tsa likarolo tse haufi), λ - bolelele ba maqhubu. Lintho tse ling tsohle tsa vector r li lekana le zero.
Letšoao le amohetsoeng ke sehlopha sa li-antenna le tlalehiloe ka mokhoa o latelang:
$$display$$y=sum_{n=1}^{N}1 ⋅exp{i2pi nfrac{d}{lambda}sinphi}$$display$$
Ha re sebeliseng foromo bakeng sa 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}$$display$$
Ka lebaka leo, re fumana:
$$display$$F(phi)=|y|^2=frac{sin^2(pi frac{Nd}{lambda}sinphi)}{sin^2(pi frac{d}{lambda}sinphi)} $ $bontša$$
Khafetsa ea mohlala oa mahlaseli
Sephetho sa sebopeho sa mahlaseli sa antenna ke ts'ebetso ea nako le nako ea sine ea angle. Sena se bolela hore ka litekanyetso tse itseng tsa karo-karolelano d/λ e na le diffraction (tlatsetso) maxima.
Paterone ea mahlaseli a sa tloaelehang ea sehlopha sa antenna bakeng sa N = 5
Mokhoa o tloaelehileng oa mahlaseli a marang-rang a li-antenna bakeng sa N = 5 tsamaisong ea polar coordinate
Boemo ba "diffraction detectors" bo ka talingoa ka kotloloho ho tsoa bakeng sa DN. Leha ho le joalo, re tla leka ho utloisisa hore na ba tsoa hokae 'meleng le geometrically (sebakeng sa N-dimensional).
Lintho vector s ke li-exponents tse rarahaneng $inline$e^{iPsi n}$inline$, boleng ba bona bo laoloang ke boleng ba angle e akaretsang $inline$Psi = 2pi frac{d}{lambda}sinphi$inline$. Haeba ho na le li-angles tse peli tse akaretsang tse tsamaellanang le litsela tse fapaneng tsa ho fihla ha leqhubu la sefofane, leo $ inline $Psi_1 = Psi_2 + 2pi m$inline$, joale sena se bolela lintho tse peli:
- 'Meleng: maqhubu a sefofane a tsoang lintlheng tsena a etsa hore ho be le phallo e tšoanang ea amplitude-phase ea oscillation ea electromagnetic holim'a likarolo tsa lethathamo la antenna.
- Geometrically: hobane litsela tsena tse peli lia lumellana.
Litaelo tsa ho fihla ha maqhubu tse amanang ka tsela ena li lekana ho ea ka pono ea sehlopha sa li-antenna 'me ha li khethollehe ho tse ling.
U ka tseba joang sebaka sa li-angles moo boholo bo le bong feela bo ka sehloohong ba DP bo lulang bo le teng? Ha re etseng sena tikolohong ea zero azimuth ho tsoa menahanong e latelang: boholo ba phetoho ea mohato lipakeng tsa likarolo tse peli tse bapileng li tlameha ho ba sebakeng sa $inline$-pi$inline$ ho $inline$pi$inline$.
$$display$$-pi<2pifrac{d}{lambda}sinphi
Ho rarolla ho se lekane hona, re fumana boemo ba sebaka se ikhethang tikolohong ea zero:
$$pontsho$$|sinphi|
Ho ka bonoa hore boholo ba sebaka sa ho ikhetha ka mahlakoreng bo itšetlehile ka kamano d/λ. Haeba d = 0.5λ, joale tataiso e 'ngoe le e' ngoe ea ho fihla ha pontšo ke "motho ka mong", 'me sebaka se ikhethang se koahela li-angles tse feletseng. Haeba d = 2.0λ, joale litsela 0, ±30, ±90 lia lekana. Li-lobe tsa diffraction li hlaha mokhoeng oa mahlaseli.
Ka tloaelo, li-lobes tsa diffraction li batloa ho hatelloa ho sebelisoa likarolo tsa antenna tse lebisitsoeng. Tabeng ena, mokhoa o felletseng oa mahlaseli a lenaka la antenna ke sehlahisoa sa paterone ea element e le 'ngoe le letoto la likarolo tsa isotropic. Litekanyetso tsa mohlala oa ntho e le 'ngoe hangata li khethoa ho ipapisitsoe le boemo ba sebaka sa ho se hlaka ha sehlopha sa antenna.
Bophara ba lobe e ka sehloohong
foromo ea boenjiniere bakeng sa ho hakanya bophara ba lobe e kholo ea sisteme ea manakana: $inline$Delta phi ≈ frac{lambda}{D}$inline$, moo D e leng sebopeho sa boholo ba lenakana. Foromo e sebelisoa bakeng sa mefuta e fapaneng ea li-antenna, ho kenyelletsa le tsa seipone. A re bonts'eng hore e sebetsa le bakeng sa lihlopha tsa li-antenna.
A re ke re boneng bophara ba lobe e kholo ka li-zero tsa pele tsa mohlala o haufi le boholo bo ka sehloohong. Numerator bakeng sa $inline$F(phi)$inline$ e nyamela ha $inline$sinphi=mfrac{lambda}{dN}$inline$. Li-zero tsa pele li lumellana le m = ±1. $inline$frac{lambda}{dN}<1$inline$ re fumana $inline$Delta phi = 2frac{lambda}{dN}$inline$.
Ka tloaelo, bophara ba mokhoa oa ho tsamaisa li-antenna bo khethoa ke boemo ba halofo ea matla (-3 dB). Tabeng ena, sebelisa poleloana e reng:
$$display$$Delta phi≈0.88frac{lambda}{dN}$$display$$
Mohlala:
Bophara ba lobe ea mantlha bo ka laoloa ka ho beha litekanyetso tse fapaneng tsa amplitude bakeng sa li-coefficients tsa boima ba antenna. A re hlahlobeng likarolo tse tharo:
- Kabo e tšoanang ea amplitude (boima ba 1): $inline$w_n=1$inline$.
- Bophahamo ba boleng bo ntse bo theoha ho ea lipheletsong tsa grating (boima ba 2): $inline$w_n=0.5+0.3cos(2pifrac{n-1}{N}-pifrac{N-1}{N})$inline$
- Maemo a holimo a ntse a eketseha ho ea lipheletsong tsa grating (boima ba 3): $inline$w_n=0.5-0.3cos(2pifrac{n-1}{N}-pifrac{N-1}{N})$inline$
Palo e bonts'a mekhoa ea mahlaseli a tloaelehileng a hlahang ka tekanyo ea logarithmic:
Mekhoa e latelang e ka fumanoa ho tloha setšoantšong: ho ajoa ha li-coefficient amplitudes ho fokotseha ho ea ka mathōko a lihlopha ho lebisa ho atolosoeng ha lobe e kholo ea mohlala, empa ho fokotseha ha boemo ba mahlakoreng a mahlakoreng. Litekanyetso tsa amplitude li ntse li eketseha ho ea fihla lipheletsong tsa sehlopha sa li-antenna, ho fapana le hoo, li lebisa ho fokotseheng ha lobe e kholo le keketseho ea boemo ba li-lobes tse lehlakoreng. Ho bonolo ho nahana ka linyeoe tse fokotsang mona:
- Li-amplitudes tsa li-coefficients tse boima tsa likarolo tsohle ntle le tse feteletseng li lekana le zero. Boima ba likarolo tse ka ntle bo lekana le e le 'ngoe. Tabeng ena, latice e lekana le AR ea likarolo tse peli e nang le nako D = (N-1)d. Ha ho thata ho lekanya bophara ba petal e kholo ho sebelisa foromo e fanoeng ka holimo. Tabeng ena, marako a mahlakoreng a tla fetoha diffraction maxima 'me a ikamahanye le boholo bo ka sehloohong.
- Boima ba ntho e bohareng bo lekana le e le 'ngoe,' me tse ling kaofela li lekana le zero. Tabeng ena, re amohetse antenna e le 'ngoe e nang le mohlala oa mahlaseli a isotropic.
Tataiso ea boholo bo ka sehloohong
Kahoo, re shebile hore na u ka fetola bophara ba lobe e kholo ea AP AP joang. Joale a re boneng mokhoa oa ho tsamaisa tsela. Ha re hopoleng bakeng sa letshwao le amohetsweng. A re batle boholo ba mohlala oa mahlaseli ho sheba ka lehlakoreng le itseng $inline$phi_0$inline$. Sena se bolela hore matla a mangata a lokela ho amoheloa ho tloha tataisong ena. Tataiso ena e tsamaisana le vector ea mekhahlelo $inline$textbf{s}(phi_0)$inline$ in N-sebaka sa vector ea dimensional, 'me matla a amoheloang a hlalosoa e le sekwere sa sehlahisoa sa scalar sa vector ena e ntseng e tsoela pele le vector ea li-coefficients tse boima. w. Sehlahisoa sa scalar sa li-vector tse peli ke boholo ha li , ke. $inline$textbf{w}=beta textbf{s}(phi_0)$inline$, moo β - ntho e itseng e tloaelehileng. Ka hona, haeba re khetha vector ea boima bo lekanang le vector ea mekhahlelo bakeng sa tataiso e hlokahalang, re tla potoloha boholo ba mohlala oa mahlaseli.
Nahana ka lintlha tse latelang tsa boima e le mohlala: $inline$textbf{w}=textbf{s}(10°)$inline$
$$display$$w_n=exp{i2pifrac{d}{lambda}(n-1)sin(10pi/180)}$$display$$
Ka lebaka leo, re fumana mokhoa oa mahlaseli ka boholo bo ka sehloohong ho ea ho 10 °.
Hona joale re sebelisa li-coefficients tse tšoanang tsa boima, empa eseng bakeng sa kamohelo ea matšoao, empa bakeng sa phetiso. Ho bohlokoa ho nahana mona hore ha o fetisetsa lets'oao, tataiso ea vector ea wave e fetoha ho fapana. Sena se bolela hore likarolo bakeng sa kamohelo le phetisetso li fapane ka pontšo ea exponent, i.e. li hokahane ka kopano e rarahaneng. Ka lebaka leo, re fumana boholo ba mokhoa oa mahlaseli bakeng sa phetisetso ka tataiso ea -10 °, e sa lumellaneng le boholo ba mohlala oa mahlaseli bakeng sa ho amoheloa ka li-coefficients tse lekanang tsa boima. sebelisa conjugation e rarahaneng ho li-coefficients tsa boima hape.
Tšobotsi e hlalositsoeng ea ho thehoa ha mekhoa ea kamohelo le phetisetso e lokela ho lula e hopoloa ha u sebetsa ka lihlopha tsa li-antenna.
Ha re bapale ka mokhoa oa mahlaseli
Libaka tse 'maloa tse phahameng
A re ke re behe mosebetsi oa ho etsa maxima a mabeli a maholo a mokhoa oa mahlaseli ka tsela: -5 ° le 10 °. Ho etsa sena, re khetha e le vector ea boima ba 'mele kakaretso e lekantsoeng ea li-vector tse tsamaeang ka tsela e lumellanang.
$$display$$textbf{w} = betatextbf{s}(10°)+(1-beta)textbf{s}(-5°)$$pontsho$$
Ho fetola karo-karolelano β O ka fetola karo-karolelano pakeng tsa mahlaku a maholo. Mona hape ho bonolo ho sheba se etsahalang sebakeng sa vector. Haeba β e kholo ho feta 0.5, ebe vector ea li-coefficients tsa boima e lutse haufi le eona s(10°), ho seng joalo ho s(-5°). Ha vector ea boima e le haufi le e 'ngoe ea li-phasors, e kholoanyane sehlahisoa sa scalar, ka hona boleng ba DP e lekanang le eona.
Leha ho le joalo, ho bohlokoa ho nahana hore mahlaku a mabeli a ka sehloohong a na le bophara bo lekanyelitsoeng, 'me haeba re batla ho tsamaisana le litsela tse peli tse haufi, joale mahlaku ana a tla kopana ho ba a le mong, a lebisitsoe lehlakoreng le leng la bohareng.
Boholo bo le bong le zero
Joale a re lekeng ho fetola boholo ba mokhoa oa mahlaseli ho tataiso $ inline$phi_1=10°$inline$' me ka nako e ts'oanang re hatelle pontšo e tsoang ho $ inline$phi_2=-5°$inline$. Ho etsa sena, o hloka ho beha zero DN bakeng sa angle e lumellanang. U ka etsa sena ka tsela e latelang:
$$display$$textbf{w}=textbf{s}_1-frac{textbf{s}_2^Htextbf{s}_1}{N}textbf{s}_2$$display$$
moo $inline$textbf{s}_1 = textbf{s}(10°)$inline$, le $inline$textbf{s}_2 = textbf{s}(-5°)$inline$.
Moelelo oa geometri oa ho khetha vector ea boima ke tse latelang. Re batla vector ena w e ne e na le khakanyo e kholo ho $inline$textbf{s}_1$inline$' me ka nako e ts'oanang e ne e le orthogonal ho vector $inline$textbf{s}_2$inline$. Vector $inline$textbf{s}_1$inline$ e ka hlalosoa e le mantsoe a mabeli: collinear vector $inline$textbf{s}_2$inline$ le orthogonal vector $inline$textbf{s}_2$inline$. Ho khotsofatsa polelo ea bothata, ho hlokahala hore u khethe karolo ea bobeli e le vector of weighting coefficients. w. Karolo ea collinear e ka baloa ka ho hlahisa vector $inline$textbf{s}_1$inline$ ho vector e tloaelehileng $inline$frac{textbf{s}_2}{sqrt{N}}$inline$ sebelisa sehlahisoa sa scalar.
$$display$$textbf{s}_{1||}=frac{textbf{s}_2}{sqrt{N}}frac{textbf{s}_2^Htextbf{s}_1}{sqrt{N}} $$pontša$$
Ka hona, ha re tlosa karolo ea eona ea colinear ho vector ea mantlha ea $inline$textbf{s}_1$inline$, re fumana vector ea boima bo hlokahalang.
Lintlha tse ling tse eketsehileng
- Hohle ka holimo, ke ile ka siea taba ea ho normalizing vector boima, i.e. bolelele ba eona. Kahoo, ho tloaeleha ha vector ea boima ha ho ame litšobotsi tsa sebopeho sa mahlaseli a mahlaseli a antenna: tataiso ea boholo bo ka sehloohong, bophara ba lobe e kholo, joalo-joalo. Ho ka boela ha bontšoa hore ho tloaeleha hona ha ho ame SNR tlhahisong ea sebaka sa ts'ebetso ea sebaka. Tabeng ena, ha re nahana ka li-algorithms tsa ho sebetsana le matšoao a sebaka, hangata re amohela ho tloaeleha ha yuniti ea vector ea boima, i.e. $inline$textbf{w}^Htextbf{w}=1$inline$
- Menyetla ea ho etsa mohlala oa lethathamo la li-antenna li khethoa ke palo ea likarolo tsa N. Lintho tse ngata, li na le menyetla e mengata. Likhato tse ngata tsa tokoloho ha u kenya tšebetsong boima ba sebaka, ho na le likhetho tse ngata tsa ho "sotha" vector ea boima sebakeng sa N-dimensional.
- Ha o amohela lipaterone tsa mahlaseli, lethathamo la li-antenna ha li teng ka 'mele, 'me sena sohle se teng feela "maikutlong" a yuniti ea komporo e sebetsanang le lets'oao. Sena se bolela hore ka nako e ts'oanang hoa khoneha ho kopanya mekhoa e mengata le ho iketsetsa lipontšo tse tsoang mahlakoreng a fapaneng. Tabeng ea phetisetso, ntho e 'ngoe le e' ngoe e batla e rarahane, empa hape hoa khoneha ho kopanya li-DN tse 'maloa ho fetisetsa melaetsa e fapaneng ea data. Theknoloji ena ea mekhoa ea puisano e bitsoa .
- U sebelisa khoutu ea matlab e hlahisitsoeng, u ka bapala le DN ka bouena
khoutu% 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]);
Ke mathata afe a ka rarolloang ka ho sebelisa li-antenna tse feto-fetohang?
Kamohelo e nepahetseng ea lets'oao le sa tsejoengHaeba tataiso ea ho fihla ha lets'oao e sa tsejoe ('me haeba mocha oa puisano o le ngata, hangata ho na le litsela tse' maloa), ka ho sekaseka lets'oao le amohetsoeng ke sehlopha sa antenna, hoa khoneha ho theha vector ea boima bo nepahetseng. w e le hore SNR ka tlhahiso ea sebaka sa ts'ebetso ea sebaka e be boholo.
Kamohelo e nepahetseng ya letshwao kgahlanong le lerata la bokamoraoMona bothata bo hlahisoa ka tsela e latelang: likarolo tsa sebaka sa pontšo e lebeletsoeng ea molemo li tsejoa, empa ho na le mehloli ea tšitiso tikolohong ea ka ntle. Hoa hlokahala ho eketsa SINR ho tlhahiso ea AP, ho fokotsa tšusumetso ea ho kena-kenana le kamohelo ea matšoao ka hohle kamoo ho ka khonehang.
Phetiso e nepahetseng ea lets'oao ho mosebelisiBothata bona bo rarolloa mekhoeng ea puisano ea mehala (4G, 5G), hammoho le Wi-Fi. Moelelo o bonolo: ka thuso ea lipontšo tse khethehileng tsa lifofane ho mocha oa maikutlo a basebelisi, litšoaneleho tsa sebaka sa mocha oa puisano li hlahlojoa, 'me motheong oa eona, ho khethoa vector ea li-coefficients tse nepahetseng bakeng sa phetisetso.
Multiplexing ea libaka tsa melapo ea dataLi-antenna tse ikamahanyang le maemo li lumella ho fetisoa ha data ho basebelisi ba 'maloa ka nako e le' ngoe ka maqhubu a tšoanang, ho etsa mohlala oa motho ka mong bakeng sa e mong le e mong oa bona. Theknoloji ena e bitsoa MU-MIMO 'me hajoale e ntse e sebelisoa ka mafolofolo ('me kae-kae e se e ntse e le teng) mekhoeng ea puisano. Monyetla oa sebaka sa multiplexing o fanoa, ka mohlala, ka mokhoa oa puisano oa mohala oa 4G LTE, IEEE802.11ay Wi-Fi standard, le litekanyetso tsa puisano tsa 5G tsa mohala.
Li-antenna tsa sebele tsa li-radarLi-antenna tsa dijithale li etsa hore ho khonehe, ka ho sebelisa likarolo tse 'maloa tsa antenna, ho theha letoto la li-antenna tsa boholo bo boholo haholo bakeng sa ts'ebetso ea mats'oao. Sebaka sa marang-rang se na le litšobotsi tsohle tsa 'nete, empa se hloka lisebelisoa tse fokolang hore li sebelisoe.
Khakanyo ea mekhahlelo ea mehloli ea mahlaseliLi-antenna tse feto-fetohang li lumella ho rarolla bothata ba ho lekanya palo, matla, mehloli ea khase ea seea-le-moea, theha khokahano ea lipalo lipakeng tsa matšoao a tsoang mehloling e fapaneng. Monyetla o ka sehloohong oa li-antenna tse feto-fetohang tabeng ena ke bokhoni ba ho rarolla mehloli e haufi ea mahlaseli. Mehloli, sebaka sa antenna pakeng tsa sona se ka tlase ho bophara ba lobe e kholo ea sebopeho sa mahlaseli a antenna (). Sena se ka etsahala haholo ka lebaka la pontšo ea vector ea lets'oao, mohlala o tsebahalang oa lets'oao, hammoho le lisebelisoa tsa lipalo tsa linear.
Kea le leboha ka tlhokomelo
Source: www.habr.com