提出了一种卫星通信多波束平面阵天线系统发射通道幅相误差星地环路校正方案,分别采用经过空域DFT变换的Walsh正交码和m/WH复合正交码作为校正测试信号验证了所提校正方案。基于该方案,分析了在LEO卫星通信系统中,卫星星下点及覆盖边缘的路径差异引起的传播损耗对校正精度的影响。仿真结果表明,当存在同步误差时,采用m/WH复合码的校正方案具有更好的鲁棒性;在不增加发射功率的情况下,当地面关口站接收天线位于扫描角0~30°时,才能获得所需的校正精度。
A new satellite-ground calibration theme is proposed, which is used for the multi-beam planar array antenna transmitting system onboard satellite. The proposed scheme is validated by using orthogonal calibration test signals generated by Walsh orthogonal codes and m/WH composite orthogonal codes, respectively. Based on the proposed scheme, the influence of position of the gateway station on calibration accuracy is analyzed in LEO satellite communications. It is shown that, with synchronization error, the calibration scheme using the m/WH composite orthogonal codes is more robust. The simulation results show that, in order to gain the desired calibration accuracy without additional transmitting power, position of scan angle of the gateway station must be restricted within the arrange of 0-30 degrees.