COFDM is the most advanced technology in the field of wireless transmission. It is the abbreviation of Coded Orthogonal Frequency Division Multiplexing (Coded Orthogonal Frequency Division Multiplexing). Its biggest advantage is to support applications that break through the line of sight limitation. Diffraction ability and penetration of obstacles are the core technology of COFDM, which can be immune to noise and signal interference.
The main function of COFDM wireless video transmission equipment is to realize the real-time transmission of wireless video. In the past, traditional wireless image transmission was mainly based on one-way analog TV broadcasting. The disadvantage of this traditional wireless image transmission is that if it is different and Since the receiving or transmitting party is in a mobile state, both the transmitting end and the receiving end may encounter strong multipath interference, so the way to deal with this interference is likely to fundamentally affect the performance of a wireless high-definition video real-time transmission system . The technology of COFDM wireless video transmission equipment just overcomes such problems.
COFDM wireless video transmission equipment has the following advantages
1. Non-line-of-sight technology, strong diffraction ability:
COFDM equipment has technical characteristics such as multi-carrier, so it has the advantages of “non-line-of-sight” and “diffraction” transmission. In an environment with many obstacles such as cities, mountains, and buildings, it can transmit stably with minimal environmental impact. The omnidirectional antenna used in the two-way transmission and reception can freely move according to different situations on the scene and the requirements of the commander/director. The entire equipment system is easy to operate, stable and very flexible in application.
2. Has excellent anti-electromagnetic interference performance:
COFDM wireless video transmission equipment has very strong anti-fading ability through the joint coding of each sub-carrier. However, in a COFDM system with multi-carrier, only a small part of the sub-chains will be interfered, and the marketing of transmission communication is small, and these sub-transmission errors can still be corrected by error correction codes, thus ensuring Low bit error rate of transmission.
3. Capable of high-speed data transmission:
High-quality video and audio require a clear and stable picture. In order to achieve such an effect, in addition to the requirements for the camera, the requirements for the channel rate and code stream are very high. However, its channel mainly uses 2M rate, which cannot meet the requirements of post analysis, storage and editing. The wireless transmission rate of COFDM equipment is generally greater than 4M bps, which can meet the transmission of video and audio data.
4. Suitable for high-speed mobile transmission:
Generally, wireless transmission equipment can only be used for fixed-point transmission. This equipment is applied to drones, ships, trains and other high-speed platforms. The usual method is to add an “antenna servo stabilization” device to the equipment, which is a good solution. Electromagnetic wave orientation, tracking, stability and other issues, but this can only achieve the transmission of moving points to fixed points under certain conditions. Moreover, its system has the disadvantages of many technical conversions, complex construction procedures, low reliability, and high cost. The equipment can be used in fixed-mobile and mobile-mobile rooms without any additional devices, and is very suitable for installation on mobile platforms such as drones, ships, and trains. The equipment not only has high transmission performance, but also has very stable performance.
Post time: Jan-15-2021