Research Of Cooperative Communication Technology In Underwater Wireless Sensor Networks

Underwater wireless sensor networks have gotten more and more attention as their applications on marine data collection, geological disaster monitoring, military security and other aspects are becoming more and more important. The underwater environment is complicated, and the channel condition is very bad. In order to effectively combat the channel fading and improve the capacity of communication system, it is necessary to apply cooperative communication in underwater wireless sensor networks. There are two problems needing to be solved. One is relay selection, and the other is power allocation. This paper researches in the two problems.This paper puts forward a new criteria for relay selection which is suitable for the application in underwater environment based on the long time delay characteristics. The new relay selection criteria considers channel conditions and transmission delay to build a comprehensive evaluation index to evaluate the merits of the relay node and to choose the best relay node. Then we allot power based on channel conditions. This paper also studies the cooperative communication system based on game theory. Referring to the Stackelberg game theory, we set the source node as a buyer and the relay node as a seller. The two parties need to decide the price of the relay node’s power and the amount of the relay node’s power through the game process. In this paper, we construct the utility function for the source node and the relay node. By maximizing the utility function, we can be informed of the optimal power value and the best price of relay node’s power.This paper uses Matlab to simulate. The results show that the relay selection method based on comprehensive standard can select the node of best comprehensive performance. Compared to equal power allocation, power allocation algorithm in this paper can effectively reduce the bit error rate and improve overall performance. Experiments also show that game theory based cooperative communication is feasible. Overall, the presented algorithm has achieved the expected requirements.