Long-term integration based on two-stage differential acquisition for weak direct sequence spread spectrum signal
Long-term integration based on two-stage differential acquisition for weak direct sequence spread spectrum signal
复制标题
基于两级差分采集的微弱直接序列扩频信号长期积分
DOI：
10.1049/iet-com.2016.0996
复制
发表时间：
2017
影响因子：
1.6
通讯作者：
Huan H
中科院分区：
文献类型：
--
作者：
Guo Yichao;Huan Hao;Tao Ran;Wang Yue;Guo Yichao;Huan Hao;Tao Ran;Wang Yue;Wang Yue;Huan H;Huan H
高动态、低信噪比对航天测控通信系统的快速捕获提出了严峻的挑战。基于二维时频搜索的方法，由于接收机资源有限，无法通过增加驻留时间来提高捕获灵敏度。为了解决这些问题，本研究提出了一种两阶段差分捕获（TSDA）算法。TDSA第一级采用差分相干积累来延长积累时间，并采用梯形变换和快速傅里叶变换来补偿线性码相位漂移，获得高积累增益。载波频偏估计是根据接收信号的两部分之间的码相位差除以TSDA的第二级，其中，避免了二维搜索过程。在相同的捕获时间和S波段空间遥测遥控通信系统典型参数下，对所提出的TSDA算法和传统的捕获方法进行了比较。仿真结果表明，与传统的捕获方法相比，该算法具有更高的捕获概率和更好的捕获灵敏度。
Fast acquisition in space telemetry and telecontrol communication system is challenged significantly by the high dynamic and low signal-to-noise ratio. Increasing the dwell time to obtain better acquisition sensitivity, based on two-dimensional time-frequency search, is impossible because of resource limitation in receiver. To tackle these problems, this study proposes a two-stage differential acquisition (TSDA) algorithm. The differential coherent integration is employed by the first stage of TDSA to extend integration time, during which keystone transform and fast Fourier transform are used to compensate the linear code phase drift and obtain high accumulation gain. The carrier-frequency offset is estimated in terms of the code phase difference between the two parts of received signal divided by the second stage of TSDA in which the two-dimensional searching process is avoided. The proposed TSDA algorithm and the traditional acquisition methods are compared under the same acquisition time and typical parameters of S-band space telemetry and telecontrol communication system. Simulation results demonstrate that the proposed TSDA algorithm attains a higher acquisition probability and better acquisition sensitivity than the traditional acquisition methods.