中文摘要：

针对扩频通信中PN码固定门限捕获性能上的不足，结合图像处理中的中值滤波和数学形态学原理，提出了一种新的自适应门限捕获方法．在分析判决量统计特性的基础上，使用由序列转换电路和形态滤波器构成的估计器对背景噪声进行实时估计，得到自适应门限用于捕获判决．蒙特卡罗仿真结果表明，该文提出的自适应门限捕获方法能够适应多径环境，抗干扰性能优越，具有较强的实用性．

英文摘要：

In view of the deficiency of the performance of fixed threshold acquisition for PN code in spread spectrum communication, a new adaptive threshold acquisition scheme is proposed by combining the median filtering with mathematical morphology in image processing. Based on the analysis of the statistical property of the decision variable, the estimator consisting of sequence conversion circuit and morphological filter is used to estimate the background noise real-timely to get adaptive threshold for acquisition decision. The Monte Carlo simulation result shows that the adaptive threshold acquisition scheme in the paper can adapt to the multi-path environment well. Its performance of anti-jamming is good and it has high practicability.