Differential preamble detection in packet-based wireless networks
Differential preamble detection in packet-based wireless networks
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DOI：
10.1109/twc.2009.071169
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发表时间：
2009-02
影响因子：
10.4
通讯作者：
S. Nagaraj;Sheehan Khan;C. Schlegel;M. Burnashev
中科院分区：
文献类型：
--
作者：
S. Nagaraj;Sheehan Khan;C. Schlegel;M. Burnashev
提出并分析了一种新的基于假设的非协调高密度分组通信的加性高斯白噪声信道前序检测方法。在长度等于序言的窗口上观察接收到的样本，并且为该窗口的每个样本移位计算度量。超过与噪声相关的预先计算的阈值的度量标记了序言的存在。前导序列由扩展序列的串联部分组成，这些扩展序列的长度最多等于信道的相干时间。然后这些部分以不同的方式组合。采用基于微分相关的检测来定位前言的边界。本文提出了一个理论框架，利用二次高斯统计的矩阵分析为前言的缺失和错误检测提供了精确的解析解。此外，还研究了该方法在双路径信道中的鲁棒性。评估了频率和时序偏移对系统性能的影响。仿真结果验证了解析表达式的正确性。此外，还将差分检测方案与非相干平方律检测器的性能进行了比较。
A novel hypothesis-based preamble detection method for uncoordinated, high-density packet-based communication over an additive white Gaussian noise channel is proposed and analyzed. Received samples are observed over a window of length equal to that of the preamble and a metric is computed for each sample shift of the window. A metric exceeding a noise dependent pre-computed threshold flags the presence of a preamble. The preamble sequence consists of concatenated sections of spreading sequences whose length is at most the coherence time of the channel. These sections are then differentially combined. A differential correlation-based detection is employed to locate the boundaries of the preamble. A theoretical framework is developed to provide exact analytical solutions for missing and falsely detecting a preamble using matrix analysis of quadratic Gaussian statistics. Furthermore, the robustness of the proposed methodology in a two path channel is studied. The effects of frequency and timing offsets on the system performance is evaluated. Simulation results are presented to validate the analytical expressions. Additionally, a performance comparison of the proposed differential detection scheme with that of a noncoherent square-law detector is presented.