Shenzhen Zhongchuang Hexin Technology Development Co., Ltd. is a young high-tech enterprise integrating product development, system integration and engineering installation. Based on wireless transmission and video application, the company follows the trend of the times and the direction of the most advanced technology development and application in the world, develops products and systems integration to serve the society. The main industries involved are: public security, security, civil air defense, military and other emergency command and mobile image transmission fixed-point monitoring.
The company is composed of a group of high-quality technical personnel and managerial personnel, relying on the strong scientific and technological forces of scientific research institutes, and under the general trend of strengthening the police and the army by science and technology, it is determined to develop, produce and sell peripheral supporting products in the field of wireless transmission and video application.
The company adheres to the principle of "being honest and doing things steadfastly". "Honesty" runs through the company's cultural construction.
System description:
Vehicle-mounted one-way mark-up image wireless transmission system is a broadcast-level mark-up image real-time transmission system produced by our company. With the current leading COFM modulation technology, it has relatively narrow air bandwidth (8MHz) and strong anti-multipath interference ability. Combining with advanced diversity reception technology abroad, it overcomes the difficulties caused by multi-path reflection and occlusion in image transmission under the conditions of analog technology and conventional modulation technology, and achieves high-speed motion or non-line-of-sight conditions. It can still transmit high quality standard image in real time, especially suitable for complex environment. Audio and video coding adopts H. 264 standard, which has the characteristics of clear picture quality, bright color and smooth image.
System features:
Anti-EMI Performance of COFDM
It has excellent performance against frequency selective fading or narrowband interference and interference between signal waveforms. It has strong anti-fading ability through the joint coding of various subcarriers. In single carrier systems (e.g. digital microwave, spread spectrum microwave, etc.), a single fading or interference can lead to the failure of the entire communication link, but in multi-carrier COFDM systems, only a small part of the subcarriers will be interfered, and these subchannels can also use error-correcting codes to correct errors to ensure the transmission of low error codes. Rate.
Anti-multipath fading performance of COFDM
It can effectively counteract the interference between signal waveforms and is suitable for high-speed data transmission in multipath environment and fading channel. When frequency selective fading occurs in the channel due to multipath transmission, only the subcarriers falling in the frequency band depression and the information they carry are affected, and the other subcarriers are not damaged, so the overall BER performance of the system is much better.
System advantages:
& The working frequency band can be customized from 300 MHz to 860 MHz.
& Middot; H. 264 video coding and decoding;
& Middot; end-to-end delay is 300 milliseconds;
& Middot; High-speed mobile and multi-path interference can be stable transmission of images, voice;
& Middot; powerful NLOS non-line-of-sight transmission capability;
& Middot; transmission power 10-30W customized;
& Middot; long transmission distance (30W vehicle-borne equipment, ground-to-ground non-line-of-sight transmission 8-15 km, ground-to-ground line-of-sight transmission 20-30 km, ground-to-air transmission 20-30 km);
& Middot; with spatial diversity receiving capability;
& Middot; dual antenna reception, signal stability, image smoothness;
& Middot; standard rack type, easy to install and use.
System application:
It can be used in public security, fire fighting, traffic police, civil air defense emergency, urban management law enforcement, environmental protection monitoring, three prevention emergency, water conservancy flood control, electric power emergency, railway emergency, maritime law enforcement, maritime inspection, customs border control, wharf monitoring, forest fire prevention, oil field anti-theft, military reconnaissance, television broadcasting, etc. Real-time mobile transmission of high-quality images in complex environments such as terrestrial environment.
System application form:
The overall transmission path is from the communication vehicle to the local command center to the general command center. The front-end video signal is transmitted back to the local command center by the communication vehicle; the local command center transmits directly to the command center through the MAN or WAN; the local command center and the command center can monitor the video signal through the monitor in real time, and can use the network monitoring, access PC to browse video and video, etc. Operation. In addition, real-time two-way voice conversation can be carried out between vehicle transmitter and system receiver.
Transmitter product characteristics:
U image quality is high, the image is clear and stable, and there is no tail phenomenon.
U power is stable and 30-45 dBm dynamic power is adjustable.
U has strong diffraction ability and supports non-line-of-sight transmission.
U is stable with COFDM modulation technology and H. 264 image compression technology.
U standard 2U frame design, working temperature < 45 C;
U device has high integration, intelligent settings and simple operation.
Transmitter product parameters:
| Product parameters | |
| project | describe |
| modulation mode | QPSK（4QAM）、16QAM、64QAM |
| Working frequency band | Exit standard frequency300-900MHzUser on-site FM adjustment, step by step as follows0.5M |
| Emission power | 45dBm，Manual adjustment within 30-45 dBm range |
| Radio Frequency Bandwidth | 1.25/2.5/6/7/8MHz Adjustable |
| Forward Error Correction | 1/2、2/3、3/4、7/8 |
| Protection interval | 1/4、1/8、1/16、1/32 |
| Video input | HDMI |
| video compression | H.264 |
| Audio interface | BNC |
| Voice interface | Interphone earplugs |
| RF interface | NType head |
| Parametric control mode | adoptLEDDigital Display Panel Adjustment Parameters |
| Encryption mode | 128positionAES(Support for custom keys, manual modification via FM board) |
| working voltage | AC220V |
| Working Current | 1.7A |
| work environment | -10~70℃ |
| Shape size | 420*335*88.8(mm) |