MIMO系统中有限反馈条件下的低功耗波束设计

为减小能量受限的多输入多输出(M IM O)系统的发射功率,该文提出了一种低功耗波束成形算法。该算法用特征矢量作为波束系数,用凸函数优化的方法优化波束之间的功率分配,使得系统在满足一定误符号率(SER)的前提下,发射功率最小。为减少反馈,该算法在发端仅需用有限的信道反馈信息——信道的相关矩阵信息或信道的均值信息,而不需完全的信道信息。结合正交空时码,该算法没有任何速率损失。仿真结果表明,与等功率波束成形算法相比,该算法能够有效地降低功耗。

Low power eigen-beamforming for MIMO systems with limited feedback

For power limited multiple-input and multiple-out(MIMO) systems,the transmit power can be reduced using eigen-beamforming to minimize the average transmit power with a constraint on the symbol error rate(SER).The weighting coefficients are calculated based on the eigen-analysis,with the optimal power loading obtained using convex optimization theory.The feedback is reduced since only channel correlation or channel mean feedbacks are needed,rather than the full channel state information.When coupled with orthogonal space-time block codes,this algorithm meets SER requirements with minimum power without any rate reduction.Simulation results show that,for the same performance,the power used by the algorithm is much less than that used by the equal-power loading algorithm.