Research And Design Of The Same Cable Broadband Transmission System Based-on C8051F MCU

Raditional analog video surveillance system is complicated, because the signal output by each of the surveillance cameras has to be connected to the monitoring center or other signal receiving device via a coaxial cable. Most common video surveillance system is a multi-point monitoring system, which makes the setting up of the system more expensive; furthermore, because of the short transmission distance and poor signal stability, such systems is difficult to apply to the medium distance video transmission. Though the emerging digital network video surveillance technology has achieved the long-distance transmission, but this technology, for its high costs, in reality is of little use. The paper mainly introduces a intelligent video surveillance system, based on the same cable broadband transmission technology and C8051F MCU, which can be effectively used in the field of video surveillance distance.The same cable broadband technology is the reversed application of the the cable TV transmission technology whose target is to avoid interference in the process of transmission so that to achieve the medium distant transmission by multi-channel video signal. The system ensures not only the quality of image transmission but also the stability reliability and feasibility in application. The system mainly consists of modulator, demodulator, directional coupler (tap), mixer (distributor), trunk amplifier, high frequency cables and other components. Modulator and demodulator are the core of the system and responsible for the high frequency video signal modulation and demodulation. This paper firstly introduces the status and the development of video surveillance systems, and the technical principles and characteristics of the same cable broadband transmission systems. Secondly, the paper investigates the structure of the system and the designing methods of modulator and demodulator, including hardware, software control circuit and the corresponding. The final part of the paper presents the performance of the system.