Research Of Cooperative Diversity And Paterner Selection

Cooperative diversity is a new spatial diversity, which enables multiple users to share their antennas and generate a virtual MIMO channels to reap some of the benefits of MIMO systems. It provides a way for MIMO technology used in small-scale mobile networks, so it has received wide attention and become a researchful hotspot in communication field. The first step for cooperative diversity to be used is the question of partner selection, but research about this is not mature yet, so making this question a priority, this paper studies cooperative diversity deeply.Firstly, based on the profoundly understanding of the character of wireless channels, this paper researches all kinds of diversity and combination, especially the spatial diversity. This paper introduces the concept of cooperative diversity, and its working principle, existing kinds of cooperative protocol are presented in this paper, also how diversity to improve system performance is analyzed mainly. Next, this paper puts an emphase on how to assign a partner for cooperation. For Ad Hoc network, an energy-saving strategy based on instant channel state information and residual energy information is proposed, and its performance is analyzed by comparesion with the method of optimal channel state information; for cellular networks, this paper researches the influence which correlation of shadow-fading has on system performance, and a partner selection method based on the correlation of the shadow-fading is introduced, the performance is researched by comparison of the instance whether correlation is considered or not. Finally, the concept that cooperative diversity can be used in underwater acoustic communication is presented in this paper, and a experimental foundation of underwater acoustic communication is established, which makes a preparation for further verifying effect of cooperative diversity.Theoretical analysis and simulation results show that enery-saving strategy of paterner selection can save energy and extend the network life while the method of paterner selection based on correlation can reduce the influence which correlation has on the system capacity and outage probability. Simulation and experimental results show that it has an application future for cooperative diversity to be used in underwater acoustic communication, and it is worthy of further research.