A Novel Frame Of Maritime Communication System Based On STBC-OFDM

With the development of the economy and the sea in our country, the number of ships at sea increases. The communication equipments in ship play an important role in daily distress and alarming. So with the knowledge of the technology used in the communication in the sea, we can give an accurate judgment and make measures with different sudden. Besides, there may be poor coordination, such as, the channel congestion and the calling being not smooth, because the ships can not assort with each other. Then, this paper advises applying the concept of mobile Ad Hoc networks to the maritime mobile communications.The main goal of wireless communication system in future is providing high-quality, high-speed service. MIMO system is just a major technology to achieve this high efficient operation. OFDM technology is a efficient modulation scheme with multi-carriers, it can effectively combat multi-path fading, and make the interfered signals be received correctly. STBC employed the OFDM technology can make the capacity of information close to the theoretical capacity. However, the current study of STBC is based on the Gaussian noise environment, in fact, there exists lots of non-Gaussian noises in the progress of communication in sea. So analysis under the non-Gaussian noise environment is more reasonable.Mobile Ad Hoc network is a unique self-organizing network with no center, no fixed base station. Applying the concept of Ad Hoc to the VHF, making it flexible in organizing network, which is the excellence of Ad Hoc network, and being transported stably and cost lower, which is the excellence of VHF. This scheme can improve the performance of the sea communication.This paper study the communication system of sea based on the STBC-OFDM technology, the consequences are as follows:â… . Model of space-time coding, modulation, channel model, model of space-time block codes, and the average symbol error rate (SER) expression of closed form solution of the space-time block codes, exported based on moment generating function (MGF), in M-PSK and M-QAM modulation system are introduced. By the two means of Monte Carlo Simulation and moment generating function based on closed form solution, a more in-depth detailed comparative study of symbol error rate performance of a variety of space-time block code modulation encoding in different ways and under different channels is did. And a number of simulation results are given. Correctness of the moment generating function based on closed form solution expression is tested.â…¡. We discuss the performance of WLAN based on OFDM technology. Firstly we expound the basic standard of WLAN and give the basic parameters under the IEEE 802.11a. And then we specifically describe the basic principle of OFDM and the implementation of OFDM. Finally the performance of the WLAN system based on OFDM technology is simulated and analyzed. By using different modulation and demodulation, different fading environments we simulated the performance and give the results.â…¢. The performance of STBC-OFDM system under non-Gaussian noise environment is given, and we give the performance with different fading chnanels.â…£. We analysis the development of the communication in sea, and introduce the GMDSS and AIS system. In addition, we discuss the routing protocols, such as, AODV, DSR, ABR and so on, and MAC protocols, for example, MACA, BAPU. Based on this, we provide a scheme, in which the Ad Hoc network is established on the VHF.