扩频通信系统PMF-FFT捕获算法检测性能的分析与提高  

Analysis and enhancement of the detection performance of the PMF-FFT acquisition algorithm for spread spectrum communication systems

作　　者：丁晟[1,2] 刘会杰[1,2] 梁旭文[1,2] 

机构地区：[1]上海微小卫星工程中心,上海200050 [2]中国科学院上海微系统与信息技术研究所,上海200050

出　　处：《高技术通讯》2012年第6期571-575,共5页Chinese High Technology Letters

基　　金：上海市自然科学基金（09ZR1430400）资助项目.

摘　　要：针对扩频通信系统部分匹配滤波结合快速傅立叶变换（PMF-FFT）捕获算法由于FFTr对频偏补偿不完全而引起相关能量衰减从而导致检测概率降低的问题，研究了检测器的输出特性，利用剩余频偏存在时检测器输出相关能量扩展的特点，提出了将相邻检测单元输出值累加作为检测变量的相邻bin联合检测方案，理论推导了该方案的虚警概率、检测概率。仿真结果表明，与原检测方案相比，该方案不仅能够提高检测概率，而且在不同剩余频偏条件下的检测具有良好的鲁棒性，适用于高动态低信噪比条件下扩频信号的快速捕获。In view of the detection probability reduction of the acquisition algorithm of PMT-FFT （ the combination of par- tial matched filtering and fast Fourier transform） for spread spectrum communication systems due to the FFT s un- tolal compensation of the frequency offset, this paper proposes a new detection scheme called adjacent bin joint de- tection based on the study of the detection output property of the detector. In the proposed scheme, the detection variable is formed by combining the consecutive bin output. The performance of the new scheme including the false- alarm probability and the detection probability is deduced. The simulation results show that the proposed scheme is suitable for the fast acquisition under the high dynamic and low SNR condition in that the detection probability is enhanced and the detection performance is robust to the frequency offset compared to the former scheme.

关 键 词：捕获 部分匹配滤波(PMF) 快速傅立叶变换(FFT) 检测 

分 类 号：TN914.4[电子电信—通信与信息系统]