| With the higher requirements of transmission data rates and quality of service, the vital problem is how to overcome the multi-path fading. MIMO technologies have become one of efficient methods to combat multi-path fading and improve the performances of system. In MIMO system, STBC and power allocatin are two hotspots in academic community. however, because of the limition of size and power cost, disposing multiple antennas in mobile terminal is unpractical. Therefore, cooperative communication technology was proposed. Combining the cooperative system with STBC and power allocation can not only make the STBC technology be widely used, but also supply a new method to optimize the performance of system.In this paper,we mainly study the power allocation and the method to improve the system's permormance in cooperative STBC system. Firstly, we separately talk about the working principle of cooperative technology and STBC technology briefly, study and simulate the performance of system carefully. then, With combining the STBC technology in cooperative communication system, we study the performance of cooperative STBC communication system over static Rayleigh fading channels. The simulation results show that: the performance of system becomes better than cooperative communication system. In the following, with the limition of total transmitting power, we study the power allocation based on different principle in cooperative communication system in the condition of static Rayleigh fading wireless networks. Conex optimization algorithm is used to optimally distribute power among source and relay nodes. Finally, with the same condition of limited power, we propose a method which aims to maximize the capacity of system to optimally distribute power among source and relay nodes in cooperative STBC communication system. The simulation results show that: after the power allocation, the performance of cooperative STBC communication system is better than cooperative communication system. |
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