一种双天线GNSS接收机混合干扰抑制方法

A Hybrid Interference Suppression Method for Dual-antenna GNSS Receivers

相对于单天线GNSS接收机,阵列GNSS接收机具有空间分辨能力,当干扰信号与卫星信号在时域频域上产生混叠时,其能够从空域上对干扰信号进行抑制,具有更强的干扰抑制能力。但阵列GNSS接收机相对于单天线GNSS接收机需要更多的阵元,随着阵元数目的增加,系统成本也相应的增加,限制了阵列GNSS接收机的应用范围。双天线GNSS接收机既具有空域抗干扰能力,同时又具有价格低廉的特点,是一种较好的折中选择。对于单一的连续波干扰,其能够产生很好的抑制效果,但是当连续波干扰中混有脉冲干扰时,由于受到自由度的限制,双天线GNSS接收机无法对混合干扰进行有效抑制,进而影响接收机的正常工作。针对于上述问题,本文提出一种新的混合干扰抑制算法。首先利用脉冲的时域特征,对待处理信号进行分块处理,确保至少有一个数据块中不含有脉冲干扰,随后对不含脉冲干扰的数据块,使用空时最小功率(Space-Time Adaptive Processing Power Inversion,STAP-PI)算法得到最优权值,然后利用该权值抑制原信号中的连续波干扰。最后,对处理之后信号中残余的脉冲干扰进行时域置零处理,从而达到抑制混合干扰的目的。仿真实验和实采实验结果均证明了所提算法的有效性。

Compared with the single antenna GNSS receiver,the array GNSS receiver has spatial resolution capabilities.When interference and satellite signals overlap in time and frequency domains,the interference signals in the spatial domain can be suppressed,thus demonstrating stronger interference suppression capabilities.However,array GNSS receivers require a larger number of antennas than single antenna GNSS receivers,and as the number of elements increases,the system cost also increases,limiting the application range of array GNSS receivers.By contrast,dual antenna GNSS receivers have both spatial interference resistance capabilities and the advantage of being cost-effective,making them suitable compromise options.They can effectively suppress continuous-wave interference but are limited in their ability to suppress mixed interference when pulse interference is present.This limitation occurs owing to the constraints on degrees of freedom for dual antenna GNSS receivers,and it can affect the normal operation of the receiver.To address this problem,this paper proposes a new hybrid interference suppression algorithm.First,the time-domain characteristics of the pulses are utilized to process the input signal in blocks,ensuring that at least one data block does not contain pulse interference.Subsequently,the Space-Time Adaptive Processing Power Inversion(STAP-PI)algorithm is applied to the pulse-free blocks to obtain optimal weights.These weights are then used to suppress the continuous-wave interference in the original signal.Finally,the remaining pulse interference in the processed signal is zeroed in the time domain,achieving the objective of suppressing mixed interference.Simulation and field experiments confirm the effectiveness of the proposed algorithm.