干扰环境中多波束阵列天线的指向优化

摘要

The simultaneous multi-beam array antenna whose pointing is fixed has limited performance of interference suppression when the interference's direction of arrival(DOA) is close to the pointing of one of the sub-beams. The pointing optimization problem is to find an optimal slightly adjusted pointing which leads each sub-beam's pointing away from strong interference and gains high output SINR, while the spatial distributing of the sub-beams remains stable. A criterion of minimizing the array's output power is used by this paper to derive an exact optimization approach and an approximate optimization approach. The latter suggests a concept of equivalent-beam which can interpret the multi-beam's response to interference. Simulation shows that the approximate approach used in non-adaptive or adaptive digital beamforming(DBF) has similar performance to the exact approach, but much lowers computational complexity.%通常多波束阵列天线的指向是固定的,在干扰环境下对于接近其子波束方向的强干扰的抑制能力较差.多波束指向优化问题是指,在子波束方位间隔保持不变的情况下,使得多波束整体指向在小范围内可调整,以尽量避开干扰进入子波束的情况,从而抑制强干扰、提高多波束输出的信干噪比.以输出总功率之和最小化为准则,推导了最优调向方法和次优的快速方法,后者用"等效波束"的概念来解释多波束对干扰信号的总体响应.仿真表明,基于自适应波束形成的快速调向方法既可接近最优调向方法的性能,又能较大地减少运算量.