Pemancar dan Penerima Video Nirkabel COFDM
Daftar isi
COFDM Wireless video transmitter and receiver Dimension
2-watt PA COFDM Wireless Video Transmitter
Ukuran: 90x65x22mm
The most recent advancements in COFDM (Multiplexing Divisi Frekuensi Ortogonal Berkode) wireless video transmitter and receiver technology have transformed how video is transmitted and received. COFDM is a modulation technique that allows digital data to be transmitted over a wide range of frequencies, resulting in a more reliable signal and improved data transmission.
We use COFDM technology in numerous applications, such as digital television, transmisi video nirkabel, dan radio digital. It’s also found in military and aerospace applications like satellite communications and unmanned aerial vehicles.
Akhirnya, recent advancements in COFDM wireless video transmitter and receiver technology have transformed the way video is transmitted and received. This technology has enabled high-definition video transmission over wireless networks, as well as video transmission over a variety of networks and devices. The use of advanced coding techniques, such as forward error correction (FEC) and adaptive modulation, has enabled this.
5-watt PA COFDM Wireless Video Transmitter
5-Watt PA COFDM-912T Weight
Package for one full set of the COFDM Wireless Video Transmitter
FAQ of the COFDM Wireless Video Transmitter and Receiver
Hai, I am looking for a long-range hd video transmitter with hdmi input and a receiver with hdmi output.
Only transmit and receive in a surveillance center. The idea is to use the HDMI output of the remote control and retransmit it to the central. The drone has a system to transmit over the internet, but there is no internet in the desert, so we need to retransmit but not with the internet.
baik, our one-way long-range wireless video transmission solution is the base of COFDM technology (similar to DVB-T digital TV broadcasting). It is not on the base of the Internet.
Does this COFDM wireless video transmitter and receiver have AES 256 atau 128 enkripsi? the output format is full hd?
iya nih, COFDM-912T supports AES 128 enkripsi. Please notify us to plus a Parameter Configuration board for setting the AES128 password when you are placing the order. It is optional to buy.
The COFDM-912T transmitter only supports SD720P Video input. So even if the receiver has HDMI output, it cannot output real 1080P high-definition video, only 720P.
If you have very high requirements on the definition of picture output, I suggest you choose a model that both the transmitter and receiver support 1080P, COFDM-908T
Can it reach 30 km around?
In the introduction of the wireless video transmission system, all the transmission distances mentioned are based on the visible range (THE). The 2WPA power amplifier supports 30 kilometers and is usually used on drones. The altitude is very high and the receiver is on the ground, so there is an obvious height difference between the transmitter and the receiver, and the wireless signal is transmitted in accordance with the waveform. The signal loss is small and other interference is very little clutter.
You mentioned that your usage scenario is that both the transmitter and receiver are on the ground, especially in desert areas, and there may be rolling sand dunes. Karena itu, the signal transmitted wirelessly is easily interfered with. So here are the suggestions:
1. Try to use a high-power transmitter, seperti 10 Watt atau 20 watt. Many of our ship customers use 20W transmitters.
2. Try to use a higher antenna or put the antenna on the roof or a nearby hill, and you can also increase the antenna tripod. Our clients always choose some 1.8-meter FRP omnidirectional fiberglass antennas.
3. If conditions permit, Sebuah pengulang can also be added to enhance the signal strength and increase the transmission distance. The repeater can be fixed at a high place or on the roof of a moving car.
How to assemble the wireless video transmitter, kamera, and battery?
Silakan periksa gambar di bawah. 
There are two power connectors at the transmitter, the red connector is 12V output for the camera, and the black connector is 12V input.
What is the lag or delay in milliseconds of your COFDM-912T?
200-300ms with a regular camera and monitor.
Normal camera and screen have a delay of 200 milidetik, kanan?
With our 100 milidetik, it’s about 300 untuk 400.
We also have one with 30 milidetik, but the price is 6 times that
300 milliseconds is acceptable if your plane has an automatic obstacle avoidance function.
I noted your transmitter can support up to 30 kilometers in LOS. How far will it support in the NLOS environment?
It’s hard to say the range of non-line-of-sight use, it depends on how many obstacles are in the middle. It is difficult to transmit if fully surrounded metal or mountains block it.
The test environment is unique, and the distance obtained from the test is also different. We can’t make any guarantees or promises about this.
We are a company that offers a solution to some rural areas here in the Philippines to monitor their rivers. If we purchased a 2W(30km) in the NLOS location, it could be reduced to 20km or more?
It is hard to say, it should depend on the obstacles between the transmitter and receiver. We don’t test it in your use environment, So I can’t tell you.
The same product will be interfered with differently in different environments, and the transmission distance is hard to say. Only the actual test will know.
Buyer: Actually, we have installed a radio transceiver that gathers a data sensor and transmits its data to an 18km distance center command. The operation is smooth and ok.
The same place we’re going to put up the device that we will buy from you.
As you have said, only an actual test will answer all of my questions.
Can the COFDM-912T TX device output separate serial data?
Data can only be transmitted in one direction from the transmitter to the receiver.
If you need to transmit data in both directions, you need to add a digital radio telemetry. (wireless data transceiver).
I would like to know if the transmitter can also output serial data on what the camera is capturing. Other than RF does it have a separate rs232 output for the transmitter?
iya nih, COFDM-912T supports transferring the serial data for you. Silakan periksa gambar di bawah. 
In this module where I can put up the camera? What type of camera is suited for this device?
The black one on the left shows a little bit of the above picture, which is connected to the camera.
It supports a 720p CVBS composite AV camera. or any HDMI camera by HDMI to AV converter box.
How can I let the transmission still work well if I remove the menu and panel board from the receiver?
Is there any way to disable the control panel so that the receiver can see the video from the transmitter?
If I remove the control panel on the receiver, the receiver does not see the signal from the transmitter.
Menjawab: Please check the FAQ in the below link.
https://ivcan.com/p/cofdm-video-transmitter-receiver-av-in-hdmi-out/#accordion-item-6._i_have_changed_the_parameter_on_the_configure_board_tool,_why_it_is_not_saving_when_i_restart?
I guess that you did not save the frequency, after you remove the menu on the receiver, the system will be back to the default frequency of 340Mhz. So you can not get the signal.
If GPS and TX are separated less than 1 meter – GPS is jammed. COFDM-912T has significant noise in GPS l1 and l2 freq. Do you have any low-pass filters to solve this problem?
Hai! We did extensive testing before ordering a bigger batch. And faced issues if combining the COFDM-912T transmitter with GPS.
Menjawab:
1. If you buy it again, I can add a low pass filter in the transmitter inside free. I can also provide an external low-pass filter for you for free.
2. “Do you know what insertion loss is in non-filtered frequency?”, Menjawab: max 0.6db
3. “Do you know what dBm loss is pass frequency?” 0.4dBm
COFDM-912T Customize Development
2 Watts default 595Mhz with 1.8-meter transmitter and receiver antenna
The client told us that his application details, the transmitter and receiver, are both used on the ground. In order to enhance the wireless transmission distance and avoid other signal interference, I recommend that both the transmitter and receiver antennas use 1.8-meter fiberglass antennas.
It was the first time the customer took the sample for testing, so he used the default two-watt amplifier and 595 MHz frequency.
The customer requires that the transmitter have an HDMI output so that he can transmit the received video to other devices. Pada waktu bersamaan, in order to support HDMI input, I also matched an HDMI to CVBS RCA AV converter box.
The customer has added an optional parameter adjustment tool, the main function of which is to modify the transmitter’s transmission frequency and impedance. You can also add a password to the wirelessly transmitted video to encrypt the video of the transmitter. We must enter the same password on the receiver to decode the video to improve the security of the video.
Change COFDM Transmitter to 200 mW PA, with a power switch of the cooling fan for body wear
Customize a video on-off switch on the COFDM Transmitter for audio-only wireless transfer.
Here is the test video for this client’s requirement, added a video on-off switch at the 10-watt PA wireless video transmitter to transfer the audio only.
Here is a video to show you that we can add one video on-off switch on the COFDM wireless video audio transmitter.
Video on, then the transmitter will transfer the video and audio at the same time.
Video off, then the transmitter will transfer the audio only.
If you have any project or need to customize the function of the wireless video transmitter and receiver, silahkan hubungi kami.
The default power amplifier is 2-watt, we also make a 10-watt PA inside, to support long-range and transfer more extended distances.
2 Watts default 595Mhz with Yagi Directional Antenna and Omnidirectional antenna
300 Watts power amplifier modified 230Mhz COFDM wireless video transmitter and receiver
FAQ
- iya nih, rentang frekuensi dapat diubah dari 170Mhz (lebih baik dari 220Mhz) hingga 860Mhz. Jadi bisa bekerja dengan baik pada band 260Mhz.
- Frekuensi harus diubah menjadi sama pada pemancar dan penerima. Dikarenakan, Penguat Daya dan frekuensi antena harus mengubah frekuensi yang sama. (Anda perlu membeli penguat daya dan antena untuk pemancar dan penerima untuk memenuhi frekuensi yang Anda ubah).
- Untuk meningkatkan sensitivitas transmisi dan penerimaan, bandwidth frekuensi umumnya dibuat sangat sempit (frekuensi pusat ±15mhz, jadi bandwidthnya harus 30Mhz). Penguat daya pemancar dan frekuensi antena disesuaikan secara khusus sesuai dengan frekuensi yang Anda butuhkan.
- Yang terbaik adalah ketika Anda memesan, tolong beri tahu saya frekuensi kerja seperti apa yang Anda butuhkan. Teknisi kami akan memodifikasi frekuensi pemancar dan penerima, dan juga memodifikasi PA dan antena khusus sesuai dengan rentang frekuensi ini untuk memastikan sensitivitas terbaik dan mendukung jarak transmisi terpanjang.
- Frekuensi default adalah 590Mhz, Dengan 30Mhz (+/-15mhz), Anda dapat mengubahnya tanpa memodifikasi Power Amplifier dan antena. Sebagai contoh, 578mhz, 584mhz, 590mhz, 596mhz, dan 602Mhz.
- Jika Anda perlu mengubah frekuensi pemancar dan bandwidth, Anda memerlukan alat khusus dari papan konfigurasi parameter, silakan lihat gambar di bawah ini, ini bukan aksesori default, Silakan membelinya dengan biaya tambahan atau hubungi kami sebelum memesan.
iya nih, ini mendukung untuk mengirim video dan data UART dari pemancar dan penerima.
Karena ini adalah transmisi satu arah, sehingga tidak dapat mengirim perintah kontrol dari penerima ke pemancar.
Jika Anda perlu mengirim perintah kontrol atau data lain dari penerima untuk mengontrol perangkat lain seperti kamera atau drone di pemancar, Anda dapat menambahkan satu set peralatan transmisi digital murah, hubungi kami, dan kami dapat menyesuaikannya untuk Anda.
Silakan periksa definisi UART pada pemancar dan penerima di tautan di bawah ini. Tolong beri tahu saya jika Anda ingin memiliki kabel timah. (defaultnya tidak)
Penguat Daya default pemancar adalah 2 watt, sehingga dapat mendukung 30 KM di line-of-sight.
Gambar di bawah ini adalah jarak yang kami uji dari gunung ke pantai.
Jika Anda ingin mengirimkan jarak yang lebih jauh, Anda dapat meningkatkan power amplifier. Selain satu watt dan dua watt, kita juga bisa membuat 5 watt, 10 watt, dan 20 watt untuk pilihan Anda. Amplifier yang lebih besar juga membutuhkan baterai yang lebih besar dan dukungan arus.
Untuk 20W PA, catu daya harus 24~28V. Hanya di 28 volt dapatkah penguat daya mencapai kemampuan kerja terbaik.
Teknisi kami dapat mengubah frekuensi menjadi 300Mhz dari default 590Mhz, Antena, dan PA di gudang adalah 590Mhz, 300Mhz membutuhkan dua minggu untuk menyesuaikan, jadi waktu pengiriman membutuhkan waktu lebih lama dari standar kami 590Mhz.
Tulis Ulang Pembaruan firmware baru untuk kotak tv digital DVB-T2 atau ISDB-T langkah demi langkah 1: Silakan tekan OK dan tombol kanan secara bersamaan, menu apakah akan menyimpan muncul di layar.
Tulis Ulang Pembaruan firmware baru untuk kotak tv digital DVB-T2 atau ISDB-T langkah demi langkah 2: Silakan tekan OK untuk memilih Ya untuk menyimpan.
Mengingatkan, silakan gunakan antena yang lebih besar atau lebih panjang jika proyek Anda memungkinkan, itu bisa mendapatkan kinerja penerimaan yang lebih baik dalam rentang yang lebih besar.
Set lengkap default
- Pemancar SD ( PA 0,5W, 1W, 2W, 5W, 10W, 20W, 50W opsional sesuai permintaan pesanan Anda)
- Antena Pemancar SD
- Penerima output CVBS HDMI dengan menu kontrol parameter dan layar kecil
- 0.8-antena penerima meteran 1 pcs. (Ada dua jenis pemasangan atau pemasangan antena: 1. antena dasar pengisap magnetik, 2. kegagalan Antena fiberglass FRP penjepit tipe U )
- Pilihan, papan konfigurasi parameter untuk pemancar video nirkabel.
(Jika Anda membutuhkan antena dasar pengisap magnetik, pihak ekspres atau pengangkut menganggap produk magnetis akan mengganggu keselamatan pesawat mereka, jadi biaya pengirimannya lebih tinggi dibandingkan antena penjepit tipe U. )
Dimensi paket set lengkap default
- 84*21*12CM
- Berat Kotor 4.5KG
- Jika Anda memilih antena lebih dari 100cm dan antena dasar pengisap magnetik, Beberapa pengirim barang akan membebankan biaya tambahan, seperti biaya ekstra panjang dan biaya tambahan untuk barang magnet yang kuat.
- Papan konfigurasi parameter pemancar berbeda dari yang ada di penerima. Firmware pada papan konfigurasi parameter berbeda dari pemancar dan penerima, mereka tidak dapat digunakan secara bergantian.
- Papan konfigurasi parameter pemancar dapat menyesuaikan pelemahan sinyal pada pemancar. Per 0,3db akan mengurangi PA 0,5W.
Pertanyaan: Apakah mungkin untuk mengubah daya keluaran (PA dalaman 0,5 w, 1 w, 2 w) melalui papan konfigurasi?
- Seperti yang dijawab di atas, Anda dapat mengatur daya keluaran dengan mengatur parameter ATTEN melalui alat papan konfigurasi parameter pada pemancar. (Alat ini tidak menyertakan paket default, Anda perlu memberi tahu bahwa Anda ingin memiliki alat ini ketika Anda memesan)
- Jika Anda membeli 2W PA, maka Anda dapat mengaturnya 0,5W, 1W, tapi tidak bisa mengubahnya menjadi 5W.
- Kami juga bisa mencapai 5W, 10W, 20W, dan 50W jika Anda perlu mendukung jarak jauh.
Tidak.
Pemancar video nirkabel ini hanya mendukung kamera CVBS atau input video, jenis kamera video lainnya memerlukan kotak konverter tambahan.
Tidak. Itu adalah COFDM (DVB-T) teknologi.
Jadi rentang frekuensi COFDM adalah 170-860Mhz. Itu dapat mendukung 477, 610, 675, 724, 816mhz, tapi tidak bisa mendukung 970, 1180, 1230 mhz.
Pemancar model khusus kami dapat mendukung semua rentang di atas, tapi penerima perlu menggunakan blok downconverter.
Untuk memungkinkan sistem transmisi nirkabel kami mendukung jangkauan yang lebih luas dan kekuatan sinyal yang lebih baik, kami biasanya mengatur frekuensi operasi ke titik tertentu (170~860Mhz), dan jangkauan yang didukungnya hanya plus atau minus 15Mhz. Sebagai contoh, frekuensi tengah adalah 590Mhz, rentang frekuensi dukungan maksimal harus 575Mhz~605Mhz, PA dan antena secara khusus disesuaikan menurut frekuensi pusat ini.
How to add a low-pass filter chip to the transmitter?
Some customers reported that when the distance between our transmitter and the GPS antenna is less than one meter, the transmitter will interfere with the work of the GPS through the transmitting antenna.
GPS satellite signals are divided into L1 and L2, with frequencies of 1575.42MHZ and 1228MHZ respectively. Our transmitter frequency is 595Mhz by default. If we encounter this situation, we can consider adding a low-pass filter, which means frequencies below 600Mhz. Frequencies above 600 MHz can be suppressed to avoid interference with other emitting electronic products.
There are two ways to add a filter. One is to add a filter IC to the COFDM-912T transmitter board, and the other is to add a filter box outside the transmitter. The down-pass filter can suppress frequencies below a certain frequency point, and the wave-pass filter can suppress the frequencies below a certain frequency point by allowing them to pass through.
