球体表面圆环阵模态域稳健高增益波束形成方法研究

通过对考虑障板影响下噪声互谱矩阵的精确求解,给出了一种计算刚性球体表面圆环阵阵增益的模型,并在此基础上提出了一种模态域二阶锥规划稳健高增益波束形成方法。该方法根据相位模态波束形成理论,将阵元域稳健加权向量转换为模态域的稳健模态系数,从而设计出不同模态阶数下的稳健高增益波束。由于采用了白噪声增益约束以及低频段较低的模态阶数,该方法提高了超增益波束形成器的稳健性。仿真结果表明该方法能够提供更多的稳健波束形成的方案,在多个关联的波束性能指标之间获得比常规方法和阵元域稳健性方法更合理的折衷。 

On robust supergain beamforming in mode space for a circular array mounted on a sphere

A model is presented for computing the array gain of circular array surrounding on a rigid sphere baffle through calculating the noise cross spectral matrix accurately.Then based on the array gain calculating model,a robust supergain beamforming method via second-order cone programming in mode space is proposed.In this method,the robust weighting vector in sensor space is transformed into robust coefficients vector in mode space according to the concept of phase modes,therefore designing robust supergain under different mode orders is available.Since the white noise constraint and low mode orders under low frequencies are adopted,the method solves the weak robustness problem of supergain beamformer especially at low frequencies.Results of computer simulation indicated that this method can provide more robust beamforming schemes and more suitable compromise among multiple beam performance parameters than both conventional method and robust beamforming method in sensor space simultaneously.