arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1707.00566cs.ITmath.IT
收藏

一种用于频谱感知的有源序贯X-ray检测器

An Active Sequential Xampling Detector for Spectrum Sensing

Lorenzo Ferrari, Anna Scaglione

摘要:

使低功率无线设备能够在高载波处采用奈奎斯特采样是禁止的。在频谱感知中,这种限制要求模拟前端能够快速扫描不同的频段,以便有机会地使用可用频谱。在本文中,我们提出了一个新的框架,允许优化的子奈奎斯特采样前端相结合的最佳顺序感测与压缩频谱感测(CSS)的好处。我们提出的感测策略被配制成一个序列效用优化问题。效用函数随着测量的数量(累积以做出决定)线性地减小,并且作为信号分量二进制状态的函数而增加。优化选择子带的最佳线性组合来混合,以便产生最大效用。效用的结构代表了探索、利用和出错风险之间的权衡,这是频谱感知问题的特征。我们首先介绍了模拟前端架构,然后映射到抽象的优化问题的测量模型,并在本文的其余部分进行了分析。我们刻画了感知矩阵约束下的最优策略,并推导出贪婪算法的逼近因子。数值模拟展示了机会频谱感知与欠奈奎斯特采样相结合的好处。

英文摘要:

Enabling low power wireless devices to adopt Nyquist sampling at high carriers is prohibitive. In spectrum sensing, this limit calls for an analog front-end that can sweep different bands quickly, in order to use the available spectrum opportunistically. In this paper we propose a new framework that allows to optimize a sub-Nyquist sampling front-end to combine the benefits of optimum sequential sensing with those of Compressive Spectrum Sensing (CSS). The sensing strategy we propose is formulated as a sequential utility optimization problem. The utility function decreases linearly with the number of measurements (accrued to make a decision) and increases as a function of the signal components binary states. The optimization selects the best linear combinations of sub-bands to mix, in order to accrue maximum utility. The structure of the utility represents the trade-off between exploration, exploitation and risk of making an error, that is characteristic of the spectrum sensing problem. We first present the analog front-end architecture, and then map the measurement model into the abstract optimization problem proposed, and analyzed, in the remainder of the paper. We characterize the optimal policy under constraints on the sensing matrix and derive the approximation factor of the greedy approach. Numerical simulations showcase the benefits of combining opportunistic spectrum sensing with sub-Nyquist sampling.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑