White Paper pa UAV Interference Technology Yotengera VCO DDS ndi SDR Technology (1)

Mwachidule

M'zaka zaposachedwa, makampani opanga ma drone akukula mwachangu, ndipo kugwiritsa ntchito ma drones kwakula kwambiri, ndipo kuchuluka kwa ma drones kukuwonetsanso zomwe zikuchitika chaka ndi chaka. Komabe, nthawi yomweyo, ma drones amakhalanso pachiwopsezo chachikulu chachitetezo m'malo osiyanasiyana pagulu. M'zaka zaposachedwa, zochitika za drones zomwe zimakhudza ndi kuwukira zida zofunikira zachitika pafupipafupi, ndipo pakufunika kufunikira kwachangu.Drone Countermiyeso luso. Pali njira zingapo zodziwira zoyeserera za drone, kuphatikiza:

• Ukadaulo wosokoneza ma siginecha opanda zingwe: Potumiza ma siginecha osokoneza mawayilesi, amasokoneza ma siginecha opanda zingwe monga chiwongolero chakutali, kutumiza zithunzi, kuyenda, ndi zina zambiri zamagalimoto apamlengalenga opanda munthu kuti akwaniritse cholinga chothamangitsa, kusokoneza, kapena kukakamiza kutera kwa drone.
• Ukadaulo wachinyengo wamawu opanda zingwe: Potumiza ma siginecha achinyengo opanda zingwe kwa ma drones, ma drones amatha kupeza zidziwitso zolakwika, potero kukwaniritsa cholinga chobera ma drones. Pali mitundu iwiri ikuluikulu ya njira zachinyengo zama siginecha opanda zingwe: kunyenga kwa chizindikiro cha malo ndi kubera ma siginolo akutali.
• Ukadaulo wowongoleredwa wowononga mphamvu: Potulutsa ma siginecha amphamvu kwambiri a laser kapena ma elekitiroma, imawononga magalimoto apamlengalenga osayendetsedwa ndi anthu, makamaka kudzera munjira ziwiri zaukadaulo: kuwononga kwa laser ndi kuwononga ma microwave kwamphamvu kwambiri.
• Kuwonongeka kwakuthupi / ukadaulo wojambula: Poyambitsa zipolopolo, mizinga yoyenda panyanja, kapena kugundana ndi ma drones, ma drones owukira amatha kuonongeka, kapena kuwombera maukonde kuti agwire ma drones.

Nkhaniyi makamaka ikukamba zaukadaulo wosokoneza ma signal opanda zingwe.

UAV Communication Protocol

Drones nthawi zambiri amagwiritsa ntchito mitundu inayi ya mawayilesi:

Chithunzi 1 Chidziwitso chofananira ndi ma waya opanda zingwe agalimoto yopanda munthu

1. RC: kutaliCndintrndil:Kutumiza malangizo kuchokera kwa woyendetsa kupita ku drone kudzera pazizindikiro zakutali, kulola drone kuchita zofananira zowuluka;
2. Mundidndindikufala:Chizindikiro cha kanema chomwe chimatengedwa ndi kamera ya drone chimatumizidwa kubwerera kumtunda wakutali, ndipo woyendetsa ntchitoyo amagwiritsa ntchito drone pogwiritsa ntchito chizindikiro chojambulidwa kuti asankhe njira yoyenera yothawa ndikupewa kugunda zopinga;

Namundigatndindin:Ma Drones amalandira ma siginecha oyimilira kuchokera ku ma satelayiti oyenda pa malo awoawo

Zizindikiro zoyendera zomwe zimawonedwa zikuphatikiza GPS, Beidou, GLONASS, ndi zina zambiri, ndipo ma frequency ogwirira ntchito amagawidwa makamaka mozungulira 1.2GHz ndi 1.6GHz.

3. Tndilndimnditrndi:Amagwiritsidwa ntchito pogawira zidziwitso za telemetry monga komwe kuli ma drones, omwe amalandilidwa ndi zowongolera zakutali ndi malo owunikira apafupi.

Pakati pawo, zizindikiro zakutali ndi zizindikiro zowonetsera zithunzi ndizo zomwe zimayang'ana kwambiri zotsutsana ndi ma radio frequency interferences, ndipo nthawi zina zimatha kusokoneza kayendedwe ka kayendedwe kake. Posokoneza ma siginecha akutali, drone sangathe kulandira malangizo kuchokera kwa wogwiritsa ntchito ndipo adzachita zozungulira kapena zobwerera; Posokoneza chizindikiro cha ndemanga za chithunzi, chowongolera chakutali sichingawonetse chithunzi chomwe chikuwoneka ndi drone, chomwe chingapangitse kuti drone iwonongeke; Ikasokoneza ma siginecha onse akutali ndi ma sign oyika ma navigation, drone siyitha kupeza chidziwitso cholondola ndikutera molunjika, kudalira masensa akupanga kuti asagwire pansi ndikuyendayenda pamtunda wina pamwamba pa nthaka.

Gome lotsatirali limatchula njira zodziwika zakutali za drone ndi njira zotumizira zithunzi. Opanga amphamvu monga DJI ndi AUTEL apanga njira zotumizira zithunzi zakutali, zomwe DJI's OcuSync ndi LightBridge ndizofala kwambiri komanso zimagwira bwino ntchito. Kwa opanga omwe alibe ma protocol odzipangira okha, ma protocol a Wi Fi nthawi zambiri amasankhidwa. Kwa DIY FPVs, protocol ya ELRS ndi TBSCrossFire zakhala miyezo yeniyeni.

 OFDM ukadaulo woyamba

LightBridge, OcuSync,Zithunzi za SkyLinkprotocol, ndiWifi, tukadaulo wa encoding wa wosanjikiza wake umatenga ukadaulo wa OFDM. Gawoli lifotokoza mwachidule zaukadaulo wa OFDM.

OFDMtechnology ndi njira yosinthira ma carriers angapo modulation multiplexing yomwe imagwiritsa ntchito ma subcarrier angapo kuti atumize deta nthawi imodzi, yokhala ndi mipata yofanana pakati pa chonyamula chilichonse. Ngakhale pali kuphatikizika kwa mawonedwe pakati pa ma subcarriers oyandikana, ndi orthogonal kwa wina ndi mnzake, kotero ma sign omwe amafalitsidwa ndi subcarrier aliyense samakhudzana. Izi zimalola kuti chidziwitso cha data chifalitsidwe nthawi imodzi pama subcarriers ambiri.

OFDMukadaulo nthawi zambiri umachokera paukadaulo wamakina a digito, ndipo njira yake yokhazikitsira ili motere: gwero la data lomwe liyenera kusinthidwa limaperekedwa kwa ma N subcarriers, subcarrier iliyonse ndi IQ modulated, ndiyeno IQ modulated data ya N subcarriers imasinthidwa ndi IFFT Fourier kusinthika kuti apeze deta ya nthawi ya IQ ya chizindikiro cha OFDM.

Chithunzi 2 Chidule cha OFDM Modulation Technology Principle

Chimango chathunthu cha OFDM nthawi zambiri chimakhala ndi zizindikilo zingapo za OFDM, ndipo kutalika kwa zizindikilo za OFDM ndikofanana ndi kagawo kakang'ono. Mwachitsanzo, pamene malo apakati ndi 15KHz, kutalika kwa chizindikiro cha OFDM ndi 66.67us. Kumayambiriro kwa chizindikiro chilichonse cha OFDM, mawu achidule a cyclic (CP) amawonjezedwa ndikuyikidwa. Zomwe zili mu CP ndi kope la zomwe zili kumapeto kwa chizindikiro cha OFDM. Cholinga chokulitsa CP ndikukana kusokoneza kwa zizindikiro zomwe zimayambitsidwa ndi kubalalitsidwa.

Chithunzi 3 Zizindikiro za OFDM ndi zonyamula

OFDMKugwiritsa ntchito bwino kwaukadaulo wa multiplexing ndikokwera kwambiri. Pafupipafupi, ma siginecha a OFDM amakhala ndi ma subcarriers ambiri, ndipo kugawa mphamvu kwa chonyamulira chilichonse kumakhala kofanana, kotero kuchuluka kwa ma sign a OFDM kuli pafupi ndi mzere wowongoka. Munthawi yanthawi, ma sign a OFDM amakhala ndi zizindikilo zingapo, chilichonse chimakhala ndi kutalika kwake.

Chithunzi 4 Zizindikiro za OFDM ndi zonyamula

 DjiLIGHTBRIDGE/OCUSYNC Ndondomeko

DjiLightBridgendiOcuSyncma protocol ndi ma benchmarks aukadaulo wama protocol akutali amtundu wa anthu wamba, ndi protocol ya LightBridge yomwe idapangidwa kale ndikugwiritsidwa ntchito kumitundu monga Phantom 3 ndi Inspire; Protocol ya OcuSync inapangidwa mochedwa kwambiri ndipo imagwiritsidwa ntchito ku zitsanzo monga Phantom 4, Mavic series, Air series, ndi zina zotero. OcuSync protocol yasinthidwa mobwerezabwereza, ndipo mawonekedwe ake atsopano ndi OcuSync 4.0. Protocol ya OcuSync 4.0 ili ndi magwiridwe antchito amphamvu komanso oletsa kusokoneza.

Chithunzi cha 5 Nthawi pafupipafupi ya DJI OcuSync protocol

LightBridge&OcuSyncwosanjikiza thupi la protocol amatengera luso la kabisidwe la OFDM, koma magawo osiyanasiyana a kabisidwe ka OFDM ndi osiyana. Protocol ya LightBridge imagwiritsa ntchito wosanjikiza wofanana ndi WiMAX, wokhala ndi malo ocheperako a 10.9375KHz. The downlink imagwiritsa ntchito 864 subcarriers, yokhala ndi bandwidth pafupifupi 9.46MHz; Protocol ya OcuSync imagwiritsa ntchito wosanjikiza wakuthupi wofanana ndi LTE, wokhala ndi malo ochepera a 15KHz. The 10M bandwidth downlink imagwiritsa ntchito ma 600 subcarriers, okhala ndi bandwidth pafupifupi 9.02MHz, pomwe 20M bandwidth downlink imagwiritsa ntchito 1200 subcarriers, yokhala ndi bandwidth pafupifupi 18.02MHz.

 SKYLINK Ndondomeko

Skylink protocol ndiyonso njira yodziwika bwino yotumizira zithunzi. Protocol ya Skylink imagwiritsidwa ntchito kwambiri mu Dao Tong EVO mndandanda wama drones.

Zosanjikiza zenizeni za protocol ya Skylink zimatengeranso ukadaulo wa OFDM, wokhala ndi bandwidth pafupifupi 10MHz ndi malo onyamula ang'onoang'ono a 15KHz.

Chithunzi 6 Chithunzi cha pafupipafupi cha SkyLink protocol

 Protocol ya Skylink imatenga gawo lofanana ndi LTE, lokhala ndi kagawo kakang'ono ka 15KHz.

 The downlink (chizindikiro chotumizira zithunzi) chimagwiritsa ntchito ma 600 subcarriers, okhala ndi bandwidth pafupifupi 9.02MHz, ndipo uplink (chizindikiro chakutali) chimagwiritsa ntchito ma subcarriers 72, okhala ndi bandwidth pafupifupi 1.1MHz.

 Wifi protocol

Wi-Ukadaulo wolumikizana ndi Fi ndiwotchuka kwambiri pamagetsi ogula, ndipo magalimoto ambiri apamtunda osayendetsedwa ndi anthu amagwiritsa ntchito Wi-Fi protocol kwa tratchulani chinthuchozizindikiro zowongolera ote ndi zizindikiro zowonetsera zithunzi. The Wi-Fi communication protocol yadutsa zaka zambiri zaukadaulo. Kuwonjezera pa Wi-Fi 1 pogwiritsa ntchito DSSS kufalikira sipekitiramu, Wi Fi wotsatira amagwiritsa ntchito ukadaulo wa OFDM wokhala ndi magawo osiyanasiyana aukadaulo monga bandwidth.

Wifi muyezo	Wifi Baibulo	Kutulutsidwa kokhazikika	Nthawi zambiri ntchito	Ukadaulo wogwiritsanso ntchito wosanjikiza	Chiwerengero cha malo oyenda	MUide-band channel	Dmitengo imeneyo
802.11	Wi-Fi 1	1997	2.4 GHz	DSSS	1	20MHz	2 Mbps
802.11b	Wi-Fi 1	1999	2.4 GHz	DSSS	1	20MHz	11 Mbps
802.11a	Wi-Fi2	1999	5 GHz	OFDM	1	20MHz	54 Mbps
802.11g	Wi-Fi 3	2003	2.4 GHz	OFDM	1	20MHz	54 Mbps
802.11n	Wi-Fi 4	2009	2.4 GHz, 5 GHz	MIMO-OFDM	Mpaka 4	20/40MHz	Mpaka 600 Mbps
802.11ac	Wi-Fi 5	2013	5 GHz	MIMO-OFDM	Mpaka 8	20/40/80/160MHz	Kufikira 3.47Gbps
802.11ax	Wi-Fi 6	2019	2.4 GHz, 5 GHz	OFDMA,MU-MIMO	Mpaka 8	20/40/80/160MHz	Kufikira 9.6Gbps
802.11be	Wi-Fi 7	2024	2.4GHz, 5GHz, 6 GHz	OFDMA,MU-MIMO	8	20/40/80/160/320MHz	Mpaka 23Gbps

The Wi-Fi yomwe imagwiritsidwa ntchito pamasewera a drones nthawi zambiri imakhala 802.11n kapena 802.11ac, monga Wi-Fi chips pamiyezo iwiriyi ndi yokhwima kwambiri. Kutengera 802.11n mwachitsanzo, nthawi zambiri pamakhala mitundu iwiri ya bandwidth

miyezo ndi okhwima kwambiri. Kutengera 802.11n mwachitsanzo, nthawi zambiri pamakhala mitundu iwiri ya bandiwifi yomwe mungasankhe, 20M ndi 40M, yokhala ndi malo ocheperako a 312.5KHz. Mu 20M mode, pali 56 subcarriers, ndipo kwenikweni wotanganidwa bandiwifi ndi za 17.8MHz. Mu 40M mode, pali 114 subcarriers, ndipo kwenikweni wotanganidwa bandiwifi ndi za 35.9MHz.

Chithunzi 7 Nthawi zambiri mawonekedwe a Wi-Khalani protocol

 FPV NdondomekoELRS/TBS

Protocol yakutali ndi protocol yotumizira zithunzi ya FPV ndizosiyana. Protocol yoyang'anira kutali nthawi zambiri imagwiritsa ntchito ELRS kapena TBS Crossfire, pomwe njira yotumizira zithunzi nthawi zambiri imatsatiridwa kuti ikwaniritse latency yochepa.

ELRS, yomwe imadziwikanso kuti ExpressLRS, ndi njira yotsegulira yoyang'anira kutali yomwe imapereka ultra-low latency komanso kutalikirana kwakutali. Zosanjikiza zakuthupi za ELRS zimatengera protocol ya LoRA ndipo imayendetsedwa kutengera tchipisi ta SEMTECH's SX127x/SX1280. ELRS imagwiritsa ntchito ukadaulo wodumphadumpha pafupipafupi ndikufalitsa ukadaulo wa sipekitiramu, womwe ungathe kukwaniritsa mphamvu zotsutsana ndi kusokoneza. Kufalikira kwa ELRS kumatengera ukadaulo wa chirp (linear frequency modulation) Kuchuluka kwa kufalikira, kumapangitsanso kufalikira, kukhudzidwa, ndi kuchuluka kwa kufalikira. Kufalikira kwa bandiwifi ya ELRS ndi 500KHz, ndipo chinthu chofalikira chimasankhidwa kuchokera ku SF6 kupita ku SF9. Ma encoding amtundu wa TBS Crossfire ndi ofanana ndi ELRS, onse pogwiritsa ntchito chirp (linear frequency modulation) kufalitsa ukadaulo wa sipekitiramu, koma kufalikira kwa bandwidth ndi 250KHz kokha.

kufalikira	Kufalikira kwa ma code spectrum	Skupeza phindu(dB）
SF6	64	5
SF7	128	7.5
SF8	256	10
SF9	512	12.5
SF10	1024	15
SF11	2048	17.5
SF12	4096	20

Chithunzi 8 Chithunzi cha nthawi pafupipafupi ya protocol ya ELRS