由于实际很难获得理想信道状态信息（CSI），传统协同波束成形算法性能严重下降。设计对信道误差具有鲁棒性的波束成形算法具有重要的实际意义。针对放大转发协同系统最大化目的节点信噪比（SNR）准则下的波束成形设计，提出对应鲁棒算法。该算法从最坏情况鲁棒设计思想出发，建立保证鲁棒性的最优化问题，应用扩展S引理和Schur补定理将该问题由初始不可解转化为可解的准凸问题，进而求解出保证鲁棒性的波束成形因子。仿真表明：同等CSI偏差下，所提鲁棒算法的中断概率性能优于传统波束成形算法。%The performance of conventional beamforming methods for cooperative system degrades severely in the presence of channel state information（CSI） imper- fection, which always occurs in practice. Hence it is of interest to develop beam- forming algorithm that is robust against CSI uncertainties. This paper addresses the problem of robust beamforming design that maximize signal-to-noise ratio （SNR） at the destination node for amplify-and-forward（AF） based cooperative systems. This algorithm formulates the problem by adopting worstcase design to grantee robust property. Based on extended S-lemma and Schur complement theorem, this origi- nally intractable problem can be transformed to a quasiconvex problem, which can be solved efficiently. Then the robust beamforming vector can be obtained. Simula- tion results show that the proposed algorithm provides better outage probability performance compared to the conventional algorithm.
展开▼
