Muva nje, imihlaba emibili ehluke ngokuphelele yahlangana ndawonye elabhorethri yethu: umhlaba wama-transceivers omsakazo angabizi kanye nomhlaba wezinhlelo ezibizayo zokuqopha amasignali omsakazo we-broadband.
Okokuqala, abangani bethu abalungile basondele kithi ukuze senze isofthiwe yokuqopha isiginali ngebhendi engu-500 MHz. Thina-ke asikwazanga ukwenqaba. Phela, kwakudingeka ukwenza lokhu ebhodini lenkampani "Instrumental Systems", engiyazi isikhathi eside. Ekuqaleni komsebenzi wami wobunjiniyela, kwadingeka ngisebenze nge-hardware yabo ne-software.
Kwabe sekufika umngane wami othandekayo kusuka ku futhi ucele ukwenza uhlelo lokubeka ama-drones ngaphandle kwe-GPS. Kudingekile, uthi, ukwethula umbukiso endlini. Futhi emgwaqeni kulezi zinsuku, awufuni ngempela ukwethula izigidi ezimbalwa zamadola esibhakabhakeni nge-GPS engathembekile. Ukuphazamiseka kokuzulazula kwe-Sat kanye ne-spoofing .
Ngokubeka ngaphandle kwamasathelayithi ngokunemba okungcono kunamasentimitha ayishumi endaweni engafika kukhilomitha, angitholanga lutho ngaphandle kobuchwepheshe be-UWB. I-DecaWave ibilokhu isemakethe isikhathi eside, ikhiqiza i-chip ye-DW1000 namamojula asekelwe kuyo. I-chip iyi-transceiver ye-UWB yezinga le-IEEE 802.15.4-2011. Ngendlela, le nto iyingqayizivele, enephansi eliphindwe kabili noma eliphindwe kathathu. Ngethemba ukuthi singafinyelela ukujula kwayo eminyakeni embalwa ezayo futhi sibhale ngayo. Ngeke neze ukwazi ukukwenza kusenesikhathi.
Kodwa namuhla asikhulumi ngokubeka; sizokhuluma ngalokho ochungechungeni olulandelayo.
Namuhla siqopha isignali ye-DW1000. Futhi i-bandwidth yalesi siginali ayikho ngaphezulu noma ngaphansi, kodwa i-1000 noma i-500 MHz, enqunywa inombolo yesiteshi. “Ngokuphelele ngephutha” kwakukhona ikhompiyutha enebhodi lesifunda etafuleni elilandelayo kusukela ku-"Instrumental Systems" nge-FMC mezzanine kusuka kumadivayisi we-Analog.
Kufanele kuqashelwe lapha "komshushisi" ukuthi i-AD9208 ADC iwubuchwepheshe obuvunyelwe namuhla. Awukwazi ukuyithenga ngokusemthethweni eRussia, nakuba ngezinye izikhathi ufuna ngempela. Kodwa le module ethile yathengwa kudala kakhulu, lapho kungakabi bikho unswinyo. Uhlanzekile, njengomphefumulo wengane. Ngethemba ukuthi lokhu kuvuma icala kuzofakwa necala futhi kuzofakwa kummangalelwa.
Ngeke manje singene emininingwaneni yokuthuthukisa isofthiwe yokurekhoda ukusakazwa kwamasampuli kumemori yekhompyutha. Ngeshwa, asikwazi okwamanje ukushicilela ikhodi yomthombo yohlelo lokusebenza lwe-Linux. Kodwa siyethemba ukuthi sizothola imvume yalokhu ngokuzayo. Kufanele kuqashelwe ukuthi lokhu kwakungelula, ngisho nokucabangela ukuthuthukiswa kwesofthiwe enikeziwe ye-Instrumental Systems. I-ADC ngokwayo kanye nesistimu yokuwasha nokukhipha amasampula kusetshenziswa ubuchwepheshe be-JESD204B kunzima ukuyiqonda, namapeshi ezingxenyekazi zekhompuyutha nawo ayedingeka kumojula evela ku-AD. Isignali ye-REFCLK iyadingeka ngokuphelele ohlelweni lokufaka, kodwa kumojula iya emilenzeni engalungile yesixhumi se-FMC futhi, ngokufanele, ayihambi emilenzeni yesokudla ye-FPGA. Kwadingeka ngifake i-patch, engabonakala esithombeni esingezansi - izintambo ezimbili ezibomvu. Yebo, kwakunokungabaza ukuthi kwakuzosebenza. Ijubane lewashi liphezulu ku-375 MHz futhi isiqeshana sibi. Kodwa uhlelo lwaphumelela.
Ikhishi lonke libukeka kanje.
Lapha ungabona ikhompuyutha enohlelo oluhle lwe-I/O, ibhodi le-FMC126P, kanye ne-AD9208-3000EBZ mezzanine. Phakathi kwamajeneretha: ijeneretha engu-3000 MHz yokuvala i-ADC, ijeneretha engu-770 MHz ye-REFCLK. Amakhebuli anezixhumi ze-SMA axhuma amajeneretha futhi anikeze isignali yokufaka.
Isivinini sedatha eluhlaza esivela ekuphumeni kwe-ADC, uma ungangeni emininingwaneni, ngu-12 GB/s eziteshini ezimbili. Ngokwezilinganiso nangokuvumelana nesimemezelo somkhiqizi webhodi le-FMC126P, isivinini sokufaka esiphezulu singu-5 GB/s. Ngakho-ke, sisebenzise isiteshi esisodwa kuphela ku-ADC futhi sayidlulisela ku-DDC (I-Digital Down Converter) eyakhelwe ku-AD9208 ngokuqedwa ngezine. Ngakho, ukugeleza kwedatha kwakungu-3 GB/s (imvamisa yesampula engu-750 MHz, isignali eyinkimbinkimbi engu-16-bit).
Ukuhlola ukuthi uhlelo lunesikhathi sokurekhoda amasampula kulula kakhulu: udinga nje ukuqapha izingcezu ezinamathelayo zesimo se-FPGA FIFO. Uma bekungekho imicimbi ye-FIFO Overflow ngobusuku obubodwa, ibhithi ngeke isethwe. Futhi sisho ngenjabulo ukuthi akukho ukulahleka kokufunda. Okokuqala sihlola, vele, ukuthi izingcezu zesimo se-latching ziyasebenza. Siphinde sibheke umumo wesignali efayelini ukuze siqiniseke ukuthi ikhwalithi yesignali ye-ADC ethwebuliwe ihambisana nokubhaliwe.
Kodwa yiluphi uhlobo lwesignali oluzofaneleka ohlelweni olunjalo lokufaka? Yebo i-UWB evela etafuleni elilandelayo!
Ngenhlanhla, sikhethe imvamisa yesiteshi esingu-4 GHz yohlelo lokumisa i-drone. Lokhu kuhambisana namashaneli 4 no-2 kumatemu e-DW1000 (Umfanekiso 13 wemininingwane). Senze ithikithi elakhelwe ebhodini lale mvamisa, noma, kangcono, kulobu bubanzi. Kwakungelula ukuyihlanganisa phezu kwebhendi ebanzi kangaka. Kodwa le nto yaphenduka inkanuko! Abanye bathi kubukeka njengophawu... ngezindlebe.
Isignali engu-4 GHz enomkhawulokudonsa ongu-500 MHz iwela ngaphakathi kwebhendi yesithathu yeNyquist futhi inezikhathi zokuqapha ezanele ukuze igweme ukubizwa ngamagama. Ngakho-ke, simane sixhuma isignali ye-DW1000 kokokufaka kwe-AD9208 ADC ngokuqondile.
Sithole amafayela amabili: elilodwa elinemvamisa ye-PRF engu-64 MHz, enye - 16 MHz. Ijubane lokudlulisela libekwe kwaba lincane kakhulu ku-DW1000 - 110 kbit/s.
Yilokho ifayela, lokhu . Qaphela, amafayela makhulu!
Efayeleni lokuqala sibona amaphakethe ahlala cishe amasampula angama-750 noma ama-nanoseconds ayi-1000.
Efayeleni lesibili, amaphakethe mafushane ngokuphindwe kane.
Futhi lokhu kuhambisana ngokugcwele nezinga le-IEEE 802.15.4-2011 ngokuya ngesendlalelo esibonakalayo se-UWB:
Ukushintshashintsha phakathi kwephakethe kufana nokushintshashintsha kwesigaba, nakho okuhambisana nalokho okushiwo kuzinga le-BPSK. Ungathola indinganiso ngokwayo ku-inthanethi, bheka i-“IEEE 802.15.4-2011”.
Uma unweba kancane iwindi lesikhathi sokubuka, ungabona futhi ukungalingani kwamaphakethe, okuhambisana nencazelo yokushintshashintsha kwe-hybrid IEEE 802.15.4-2011 UWB - isikhundla-isigaba (BPM-BPSK).
Ngokuvamile, ngithola i-chip ye-DW1000 kanye nokuguqulwa kwe-UWB PHY kube ibhomu, noma ngabe lokho kusho ukuthini, into ethile, ezingeni le-JTIDS yezempi. Lona umsebenzi wami omusha wokuzilibazisa. Kuzoqhutshwa!
Ngakolunye uhlangothi, sizomba i-DW1000, ngakolunye, sizobhekana nezinga le-IEEE 802.15.4.
Source: www.habr.com