星地融合认知网中下行波束形成算法

Downlink Beamforming Algorithmfor Cognitive Hybrid Satellite-Terrestrial Network

针对卫星网络和地面网络频谱共享的星地融合网,提出了一种基于上下行链路对偶原理的下行波束形成(beamforming,BF)算法。在最大发射功率受限的多天线基站对卫星主用户(Primary User,PU)的干扰总功率小于门限值的约束下,为满足多个地面网络次用户(Secondary user,SU)的最小信干噪比(signal-to-interference-plus-noise ratio,SINR)高于一定门限值的要求,基于上下行链路对偶原理和次梯度方法,设计出一种迭代算法求解出下行链路最优的波束形成权矢量和功率分配矢量。最后,仿真结果验证了算法的收敛性和有效性。

A downlink beamforming（BF） algorithm is advanced in a cognitive hybrid satellite-terrestrial network（H- STN）,where the interference leakage to the primary user（PU） is below an allowable threshold.The maximum tra-nsmitted power of base station is limited and channel information is available at the transmitter.Based on the up- link-downlink duality and subgradient algorithm,the optimal BF vector and power allocation vector are obtained to guarantee the minimum signal-to-interference-plus-noise ratio（SlNR） of the secondary users（SUs） is higher than a threshold.Simulation results validate the effectiveness and illustrate the convergence of the proposed algorithm.