Matekiniki ekutumira masaini edhijitari
Kuvandudzwa kwetekinoroji yemazuva ano yekutaurirana kwakabatana zvisingaparadzanisike nekugona kwevanhu kutumira data nekukurumidza, nemazvo, uye zvakavimbika. Kubva pakufona kwezwi kunobva kuVoIP uye kutenderera kwevhidhiyo kusvika pakutaurirana pakati pemidziyo paInternet of Things (IoT), zvese zvinoenderana nekutumira masaini edhijitari. Kusiyana nemasaini eanalog, ayo ari mafungu anoenderera mberi, masaini edhijitari anomiririra ruzivo muchimiro chakasiyana (kazhinji mabhiti 0 ne1). Nekuda kwehunhu hwavo hwakasiyana, masaini edhijitari anodzivirira zvakanyanya kukanganiswa uye ari nyore kugadzirisa nemidziyo yekombuta. Zvisinei, kuti data redhijitari rifambe madaro marefu uye ripe mhando yepamusoro, matekiniki akakodzera ekutumira anodiwa. Chinyorwa chino chinokurukura pfungwa huru nematekiniki mukutumira masaini edhijitari, kubva pakunyora makodhi, modulation, multiplexing, kusvika pakudzora kukanganisa.
1. Pfungwa huru dzekutapurirana kwedhijitari
Kutumira masaini edhijitari inzira yekutumira data redhijitari kubva kune chinotumira kuenda kune chinogamuchira kuburikidza nechinhu, senge waya yemhangura, fiber yemaziso, kana mafungu eredhiyo. Chinangwa chikuru ndechekuona kuti mabhiti anotumirwa anogamuchirwa nechiyero chidiki chekukanganisa, pasinei nemiganhu yakaita sekuderera kwesimba, ruzha, kupindira, uye kukanganiswa.
Kushanda kwekutumira kunowanzo kuyerwa nematanho akati wandei, anosanganisira:
- Bit rate (bps): huwandu hwemabhiti anotumirwa pasekondi.
– Bandwidth: huwandu hwemafrequencies anogona kupfuura nepakati pemidhiya.
– SNR (Signal-to-Noise Ratio): chiyero chesimba rechiratidzo kune ruzha.
– BER (Bit Error Rate): mukana wekukanganisa kwebit kana yagamuchirwa.
- Kunonoka uye kushamisika: kunonoka uye kusiyana kwaro, zvakakosha kumasevhisi enguva chaiyo.
Nekunzwisisa ma parameter aya, vagadziri vemasystem vanogona kuona matekiniki akakodzera kwazvo kuti vawane kugona kunodiwa uye kuvimbika.
2. Kunyora mitsara: kushandura mabhiti kuita zviratidzo pamidhiya
Kuti mabhiti "aonekwe" pamagetsi chaiwo, nzira dzekunyora mitsara dzinoshandiswa. Kunyora mitsara kunoratidza kuti 0s na1s zvinomiririrwa sei semavoltage, macurrents, kana shanduko yemazinga echiratidzo.
Dzimwe nzira dzakajairika dzekunyora makodhi emitsara ndeidzi:
– NRZ (Non-Return-to-Zero): mabhiti 1 ne 0 anotaridzwa nemazinga akasiyana emagetsi asingadzokeri ku zero pakati pebhiti. Zviri nyore, asi zvinogona kuva dambudziko pakuwiriranisa kana paine kutevedzana kwenguva refu kwemabhiti.
– RZ (Kudzokera kuZero): chiratidzo chinodzokera kuzero panguva yega yega yebit, zviri nyore kuenderana asi chinoda bandwidth yakakura.
– Manchester coding: shanduko iri pakati pechinhu inoshandiswa pakubatanidza (semuenzaniso, 1 = kuchinja kumusoro, 0 = kuchinja pasi). Inoshandiswa zvakanyanya muzvizvarwa zvekutanga zveEthernet.
– AMI (Alternate Mark Inversion): bit 0 i0 volts, bit 1 inochinjana pakati pezvakanaka nezvakaipa. Izvi zvinoderedza DC component uye zvinobatsira pakuona zvikanganiso.
Kusarudzwa kwekunyora mitsara kunokonzerwa nezvinodiwa pakuwiriranisa, kushanda zvakanaka kwebandwidth, uye hunhu hwemidhiya. Masisitimu emazuva ano anowanzo shandisa zvirongwa zvakaoma kunzwisisa kuti awedzere spectrum uye kuvimbika.
3. Kuchinja kwedhijitari: kutakura data pamudziyo wekutakura
Kana data redhijitari richitumirwa kuburikidza nechiteshi che bandpass senge redhiyo kana network yeserura, kuchinjika kwedhijitari kunodiwa. Kuchinjika kunobatanidza mabhiti nekuchinja kwema parameter emafungu emutakuriri, akadai se amplitude, frequency, kana phase.
Mhando huru dze digital modulation dzinosanganisira:
– ASK (Amplitude Shift Keying): mabhiti anomiririrwa nekuchinja kweamplitude. Zviri nyore, asi zviri nyore kukanganiswa neamplitude noise.
– FSK (Frequency Shift Keying): mabhiti anomiririrwa nekuchinja kwema frequency. Hainzwi ruzha zvakanyanya, inowanzoshandiswa mumasystem ekutaurirana ari nyore uye ma modem ekare.
– PSK (Phase Shift Keying): mabhiti anomiririrwa nekuchinja kwechikamu. Anowanzoonekwa nekuda kwekushanda kwayo zvakanaka uye kusimba kwayo.
– QAM (Quadrature Amplitude Modulation): inosanganisa amplitude uye phase changes kuti ikwanise kutakura ma bits akawanda pachiratidzo chimwe nechimwe. Mienzaniso inosanganisira 16-QAM, 64-QAM, uye kunyange 256-QAM paWi-Fi neLTE/5G.
Pfungwa dzakakosha mukuchinja kwezwi nderekuti symbol rate (baud) uye bits per symbol. Nekuwedzera modulation order (semuenzaniso, kubva kuQPSK kuenda ku16-QAM), system inogona kutumira ma bits akawanda per symbol, nokudaro ichiwedzera throughput. Zvisinei, ma oda akakwira anowanzo da SNR iri nani kuti irambe iine BER yakaderera.
4. Multiplexing: kugovana midhiya kune vashandisi vakawanda
Mukuita, masaini akawanda anowanzo shandiswa panguva imwe chete pane imwe nzira yekutumira data. Apa ndipo panoshanda multiplexing, nzira inosanganisa data streams dzakawanda kuitira kuti dzikwanise kutumirwa panguva imwe chete.
Dzimwe nzira dzakajairika dzekuwedzera huwandu hwema "multiplexing":
– TDM (Time Division Multiplexing): mushandisi wega wega anowana nguva. Yakakodzera masisitimu akarongwa anoda kugoverwa kwakatarwa.
– FDM (Frequency Division Multiplexing): chiratidzo chega chega chinoiswa pabhendi rema frequency akasiyana. Chinoshandiswa muredhiyo, cable TV, uye mamwe masystem e analog needhijitari.
– WDM (Wavelength Division Multiplexing): shanduro yeFDM pafiber ye optical, inoshandisa marefu akasiyana echiedza. WDM inogonesa kugona kwakanyanya pa internet backbone.
– CDM/CDMA: vashandisi vanosiyaniswa nekodhi yavo yekupararira. Izvi zvaimbove zvakanyanya pama network e3G cellular.
Mumatekinoroji emazuva ano akadai seLTE ne5G, matekiniki akavakirwa paOFDM (Orthogonal Frequency Division Multiplexing) anoshandiswa ayo anokamura nzira kuita ma subcarriers akawanda e orthogonal, zvichiita kuti kutapurirana kuve nyore kudzivirira multipath uye kushanda zvakanaka kwe spectrum.
5. Kubatanidza uye kuumba fremu
Mukutumira data nedhijitari, mugamuchiri anofanira kuziva kuti chikamu chinotanga uye chinopera riini, uye kuti angakamura sei data kuita zvikamu zvine musoro. Maitiro aya anosanganisira:
- Kudzoreredza wachi: kudzoreredza wachi kubva pachiratidzo chakagamuchirwa kuti chitore sampuli panguva chaiyo.
– Kuisa furemu: kuratidza kutanga/kuguma kwefuremu kana paketi, semuenzaniso netsamba yekutanga, musoro, uye checksum.
Pasina kuenderana zvakanaka, mabhiti anogona kudonha uye kukonzera zvikanganiso zvakawanda. Nokudaro, mapuroteni mazhinji anowedzera mapatani chaiwo kana kushandisa matekiniki ekunyora mitsara kuti zvive nyore kudzoreredza wachi.
6. Kudzora kukanganisa: kuona nekugadzirisa
Kukanganiswa kwechiteshi kunogona kukonzera zvikanganiso zvema bit. Kuti izvi zvisaitike, nzira dzekutonga zvikanganiso dzinoshandiswa, dzinosanganisira:
1. Kuonekwa kwezvikanganiso
– Parity bit: inowedzera 1 bit kuti ione kana nhamba ye1 bits isina kujairika/yakaenzana.
- Checksum: kuunganidzwa kwedata kwakanangana, kwakajairika mumaprotocol enetwork.
– CRC (Cyclic Redundancy Check): nzira ine simba uye inoshandiswa zvakanyanya muEthernet, Wi-Fi, uye mapuroteni akasiyana-siyana ekutaurirana.
2. Kugadzirisa kukanganisa (FEC: Kugadzirisa kukanganisa mberi)
- Kodhi yeHamming: inogona kugadzirisa zvikanganiso zve 1 bit mune imwe block yedata.
– Kodhi yeConvolutional, Reed-Solomon, LDPC, Turbo code: inoshandiswa mukutaurirana kwemazuva ano (Wi-Fi, 4G/5G, satellite) kudzvinyirira BER pasina kutumirazve.
Kunze kweFEC, kunewo nzira yeARQ (Automatic Repeat ReQuest), apo mugamuchiri anokumbira mutumi kuti atumirezve data kana paine chikanganiso chakaonekwa. Musanganiswa weFEC neARQ unowanzo shandiswa kuyera nguva yekunonoka, throughput, uye kuvimbika.
7. Nhepfenyuro yekutumira mashoko nematambudziko ayo
Maitiro ekutumira mashoko nedhijitari anokanganiswawo nenhau:
– Tambo yemhangura: yakachipa, asi inogona kukanganiswa nemagetsi uye inodzikira zvakanyanya pamagetsi akakwira.
– Fiber yemaziso: bandwidth yakakura kwazvo, kuderera kwesimba remagetsi, uye kuramba kukanganiswa, asi kuiswa kwemidziyo yemaziso nemaziso kwakaoma zvikuru.
– Wireless: inochinjika, asi inotarisana nematanho akawanda, kupera simba, kupindira, uye miganhu ye spectrum.
Saka, masisitimu emazuva ano asina waya anoshandisa nzira dzinochinja-chinja dzakadai se adaptive modulation and coding (AMC), uko maitiro e modulation ne coding anochinja zvichienderana nemamiriro echiteshi.
8. Mashandisirwo uye mafambiro ekuvandudza
Kutumirwa kwemasaini edhijitari kunoshandiswa munzvimbo dzinenge dzese: ma network emakomputa, nharembozha, masateraiti, masisitimu ekufambisa, uye kunyangwe kutaurirana kwemotokari nemaindasitiri. Mafambiro aripo parizvino ndeekushanda zvakanaka kwespectrum uye kuvimbika kwakanyanya, semuenzaniso mu5G/6G, network dze optical dzine simba reterabit, uye kutaurirana kwesimba shoma kweIoT.
Matekinoroji akadai seOFDM, MIMO (Multiple-Input Multiple-Output), uye advanced coding (LDPC/Polar) anoratidza kuti kutumira kwemashoko edhijitari kuri kuramba kuchichinja. Chinangwa chikuru chinoramba chiri chimwe chete: kutumira mashoko akawanda, nekukurumidza, uye nguva dzose, pasinei nekusakwana kwenzira dzekutaurirana.
Mhedziso
Matekiniki ekutumira masaini edhijitari anosanganisira maitiro akasiyana-siyana: kunyora mitsara kumiririra mabhiti pamedia, modulation yekutakura data mu bandpass channel, multiplexing kubvumira vashandisi vakawanda kugovera media, kuenderana kwekugamuchira panguva, uye nzira dzekuona nekururamisa zvikanganiso kuchengetedza kuvimbika kwedata. Kusarudzwa kwenzira yakakodzera kunoenderana nezvinodiwa zvekushandisa, hunhu hwemedia, uye zvinangwa zvekushanda zvakaita se bit rate ne BER. Nekufambira mberi kwetekinoroji, kutumira kwedhijitari kuri kuramba kuchishanda zvakanaka uye kuchichinja, zvichiita kuti masevhisi ekutaurirana akurumidze uye akavimbika muzvikamu zvakasiyana-siyana zvehupenyu.
