GPS接收机的自适应门限设定方法

GPS接收机的自适应门限设定方法

管璇;巴晓辉;牟荣增;程亚奇;陈杰

【期刊名称】《电子器件》

【年(卷),期】2007(030)002

【摘要】The aim of this paper is to present a novel threshold setting algorithm by which both the false alarm rate and the probability of detection could be kept constant in a range while the SNR of received signals varies.What makes it different from the former adaptive threshold setting rules is that it is not based on the conventional CFAR criterion but on a novel constant equivalent signal to noise ratio(CESNR)criterion. Since only when the output SNR is constant can the probability of detection be kept stable along with a desired false alarm rate,the goal of the threshold detector is to maintain a constant output SNR by using the non-coherent combination.On one side,the adaptive threshold is set as a function of the estimatednoise power,thus guarantee the accumulated output that exceed the threshold would reach a required resulting signal to noise ratio.On the other side,the number of tested samples is adaptively adjusted,which means,the integration time is increased until the non-coherent correlation output exceed the threshold.Therefore,whenever a detection is declared,the resulting SNR is constant,so that the probability of detection and the false alarm rate could be kept constant no matter how much the input