Research On Ship-shore Data Remote Transmission System Based On Spread Spectrum Communication Technology

Ship-shore data remote transmission system is the important technical means to realize ship-to-shore information sharing. Traditional ship-shore data remote transmission technology almost use mobile communication network or satellite communication network technology, the data transmission's performance such as reliability, security in many applications cannot meet the need. In view of the spread spectrum communication technology have superior properties such as CDMA, resistance to multipath interference,this paper designed and implemented based on spread spectrum communication technology of ship-shore data remote transmission system.First, we discuss and analysis the shore development present situation of data remote transmission system of the vessel, and discuss the basic principles of spread spectrum communication technology. We use pseudo-random sequence of m sequence to simulate three spread-spectrum approach and compared them, direct sequence spread spectrum technology eventually selected as the data communications between ship and shore remote data transmission system.Second, based on direct sequence spread spectrum communication technology, this paper design ship-shore telecommunication integrated equipment, and analysis M-sequence based on m-sequence, based on the design of two M-sequence pseudo-random code as the spreading code broadening the bandwidth of signal, at the receiving side combined with the spread spectrum signal and digital correlator to despread the received signal. Design ship-shore telecommunication mechanism, ship-shore communication mode remote burst and develop ship-shore communication data format.Third, this paper design ship-shore data remote transmission experiment system based on spread spectrum communication technology, inboard side design data acquisition system based on programmable logic controller. The collected data is transmitted to vessel packaging computer, the computer organized the received data into a data format that can be identified by spreading equipment, then sent the data to the vessel spread spectrum communication terminal equipment, the equipment will expand frequency band of the data transmit from computer, then the spread signal is transmitted to the shore of the receiver via a wireless channel. Shore-side receiver despread the received signal correspondingly, restore the original data to the server, the data management software manage the data in the server.Realized the boat and shore-side data remote transmission end received in real time,shore-side use of the database to the state of navigation data management, recording historical data, do review of ship navigation path.