一种改进的多波束卫星通信系统功率分配算法

摘要

Allocating the power resource reasonably in satellite systems can improve the efficiency of resource. In order to solve the problem that the algorithm complexity based on using iterative water-filling algorithm to allocate power in multi-beam satellite systems is too high, a modified algorithm was proposed. The modified algorithm based on the limit of power and capacity takes the use of the same nonnegative dual variables of power allocation for each beam in Lagrange function to establish equation, so that we can get the whole results of power allocation as long as we know one of them. The iterative computations are voided with the modified algorithm while its complexity considerably decreases. Simulation shows that the modified algorithm is able to reduce the complexity of operation effectively, and its performance loss is very small compared with iterative water-filling algorithm at the same time. Meanwhile, the impacts of the BER and the number of beams on the modified algorithm are discussed.%对卫星通信系统进行合理的功率分配，可以提高功率资源的利用效率。针对多波束卫星通信系统功率分配中采用的迭代注水分配算法存在的实现复杂度高的问题，提出了一种改进的注水算法。该算法基于功率和波束容量受限的约束条件，利用Lagrange函数中每个波束的功率分配结果的非负对偶变量值相等建立等式，由一个波束的功率分配结果则可得到所有的波束功率分配结果，避免了功率分配过程中的迭代计算，从而有效降低了计算复杂度。仿真结果表明，在系统性能基本保持不变的条件下，该算法显著降低了运算复杂度。此外，探讨了系统误码率和波束数目对改进注水算法的影响。