Weak global navigation satellite system（GNSS） signal acquisition has been a limitation for high sensitivity GPS receivers. This paper modifies the traditional acquisition algorithms and proposes a new weak GNSS sign...Weak global navigation satellite system（GNSS） signal acquisition has been a limitation for high sensitivity GPS receivers. This paper modifies the traditional acquisition algorithms and proposes a new weak GNSS signal acquisition method using re-scaling and adaptive stochastic resonance（SR）. The adoption of classical SR is limited to low-frequency and periodic signals. Given that GNSS signal frequency is high and that the periodic feature of the GNSS signal is affected by the Doppler frequency shift, classical SR methods cannot be directly used to acquire GNSS signals. Therefore, the re-scaling technique is used in our study to expand its usage to high-frequency signals and adaptive control technique is used to gradually determine the Doppler shift effect in GNSS signal buried in strong noises. The effectiveness of our proposed method was verified by the simulations on GPS L1 signals. The simulation results indicate that the new algorithm based on SR can reach-181 d BW sensitivity with a very short data length of 1 ms.展开更多
在雷达探测领域,由于线性调频(linear frequency modulation,LFM)信号近主瓣区的较高旁瓣电平,强目标旁瓣对弱目标的遮盖现象使得传统雷达对这类弱目标的检测能力大幅下降。对于这一问题,提出一种混沌波形近主瓣区低旁瓣的优化方法。该...在雷达探测领域,由于线性调频(linear frequency modulation,LFM)信号近主瓣区的较高旁瓣电平,强目标旁瓣对弱目标的遮盖现象使得传统雷达对这类弱目标的检测能力大幅下降。对于这一问题,提出一种混沌波形近主瓣区低旁瓣的优化方法。该方法在保持混沌波形优秀的抗截获和抗干扰能力的基础上,结合混沌波形较低的旁瓣电平的特性,充分利用双混沌信号设计的频谱特性和失配滤波器时频自由度来调整脉冲压缩后信号的能量分布。仿真结果表明,所设计的混沌波形具有比较好的距离分辨率,并且经失配滤波器脉冲压缩后的近主瓣区的旁瓣电平达到较低水平,对检测距离相近情况下的弱目标具有一定意义。展开更多
基金supported by the National Natural Science Foundation of China(61202078)
文摘Weak global navigation satellite system（GNSS） signal acquisition has been a limitation for high sensitivity GPS receivers. This paper modifies the traditional acquisition algorithms and proposes a new weak GNSS signal acquisition method using re-scaling and adaptive stochastic resonance（SR）. The adoption of classical SR is limited to low-frequency and periodic signals. Given that GNSS signal frequency is high and that the periodic feature of the GNSS signal is affected by the Doppler frequency shift, classical SR methods cannot be directly used to acquire GNSS signals. Therefore, the re-scaling technique is used in our study to expand its usage to high-frequency signals and adaptive control technique is used to gradually determine the Doppler shift effect in GNSS signal buried in strong noises. The effectiveness of our proposed method was verified by the simulations on GPS L1 signals. The simulation results indicate that the new algorithm based on SR can reach-181 d BW sensitivity with a very short data length of 1 ms.
文摘在雷达探测领域,由于线性调频(linear frequency modulation,LFM)信号近主瓣区的较高旁瓣电平,强目标旁瓣对弱目标的遮盖现象使得传统雷达对这类弱目标的检测能力大幅下降。对于这一问题,提出一种混沌波形近主瓣区低旁瓣的优化方法。该方法在保持混沌波形优秀的抗截获和抗干扰能力的基础上,结合混沌波形较低的旁瓣电平的特性,充分利用双混沌信号设计的频谱特性和失配滤波器时频自由度来调整脉冲压缩后信号的能量分布。仿真结果表明,所设计的混沌波形具有比较好的距离分辨率,并且经失配滤波器脉冲压缩后的近主瓣区的旁瓣电平达到较低水平,对检测距离相近情况下的弱目标具有一定意义。
