A new communication system based on OFDM in coal mine underground

In this paper, the signal sources of communication system are described in coal mine firstly, and then a kind of comprehensive information communication system based on the OFDM technology is presented. This system makes wire communication combined mutually with wireless communication by tandem adapter. Wireless communication system primarily include through-the-earth communication, inductive communication and microwaves communication system, etc. Wireless communication is used in mining area or in the time of sudden accident. Power line or leaky cable is used in main lane. The technology of OFDM combines with multiple access technology and various modulations technology easily. This system makes use of the advantage of OFDM technology to provide many kinds of access service in mine. There are different grades and different rates for many consumers at the same time in these access services. The different modulation methods of sub-carries in this system increase flexibility and adaptability. The system not only fulfils the usual demand of produce communication monitoring, but also considers sudden accident, attains the state where the mining area arrives where the signal transports. This paper analyzed feasibility of the system based on some simulation tests finally.