Radio-frequency interference will cause severe degradation of GPS receiver such as cannot track the useful signal and position. Adaptive nulling antenna is an effective anti-jamming measure for GPS receiver. In this paper, we studied the algorithms principle of power inversion(PI), multiple signal classification(MUSIC). In computer simulation, the algorithms were adopted in planar array with four antennas in the shape of Y, the antenna gain in the useful signal and interference directions were compared. We used a narrowband interference, a narrowband and a wideband interferences in the simulation. The simulation result indicates that the two algorithms can be used for GPS receiver to achieve anti-jamming. Despite the fact that MUSIC will introduce a lot of false nulls, it has a better interference suppression performance than the PI. As it is simple and easy to achieve, the power inversion algorithm has been widely used in engineering.%研究全球定位系统优化定位精度问题时,射频干扰严重影响GPS接收机的正常信号,直接导致接收机无法跟踪锁定有用信息,从而无法精确定位.自适应调零天线是一种有效的抗干扰措施.提出了功率倒置算法、多重信号分类算法的基本原理,在4元Y平面阵中对各算法进行仿真,比较各算法在有用信号和干扰来向上得到的天线增益.仿真中分别使用一个窄带干扰以及一个窄带干扰和一个快带干扰.仿真结果表明,两种算法都可用于GPS接收机抗干扰,对功率倒置算法抑制干扰性能较弱,多重信号分类算法会引入错误的零陷.由于简单和易实现,功率倒置算法广泛应用于工程.
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