基于非正交码的波束形成网络幅相测试方法

An amplitude-phase measurement method for beam forming network with non-orthogonal codes

针对目前数字波束形成网络幅相一致性测试系统中扩频码受限于正交码的问题,提出了一种基于非正交码的数字波束形成网络幅相测试方法。基于非正交码的幅相测试精度受多址干扰影响,提出了使用解相关算法提高幅相测试精度的方法,该方法以噪声略有增加为代价消除了多址干扰。理论分析给出了幅相测试的理论下界,并分析了系统误差、通道间耦合对幅相测试精度的影响。仿真结果显示,当采用非正交码时,测试设备不使用解相关算法无法达到预设的精度要求;使用解相关算法后,基于非正交码的幅相测试可以达到理论下界,在带内信噪比为10dB条件下,幅相测试精度为±0.1dB/1°,可以满足实际系统需求。

The application of an amplitude and phase measurement system based on the spreading codes is limited by the requirements of code orthogonality.An amplitude-phase measurement method for digital beam forming network based on non-orthogonal codes was proposed to overcome the limitation.The main source of errors in the measurement system with non-orthogonal codes was multiple access interference（MAI）.Therefore,de-correlating algorithm was proposed to suppress the MAI at the cost of increasing the noise slightly.Theoretical analysis provided the theory lower bound of the amplitude and phase measurement and the effect of the system error and mutual coupling on the measurement accuracy.Simulation results demonstrate that the accuracy of the measurement system without de-correlating algorithm is unacceptable.However,the proposed method can satisfy the accuracy requirements of ±0.1dB and ±1 degree under the conditions that the in-band signal-to-noise ratio（SNR）is higher than 10 dB.Moreover,the simulation results are in good agreement with those of theoretical analysis.