In this paper, first, energy detection (ED) based spectrum sensing inorthogonal frequency division multiplexing (OFDM) system using National Instrument (NI) Universal Software Radio Peripheral (USRP) 2942R software defined radio platform has been implemented. It is observed that in practical scenario ED scheme gives poor performance at low gain (G) values. To overcome the shortcomings of energy detection, we propose eigenvalue based detection of the primary user (PU) signal, where the ratio of the maximum eigenvalue to the average eigenvalue is used to detect the PU signal in both the single and multiple antenna systems/SISO and multiple‐input and multiple‐output (MIMO) based CR user. The analytical expression of the performance metric (probability of detection [P_d]) has been derived. Further, the experimental studies show that proposed technique gives optimum (P_d) in both SISO and MIMO case. It has been observed that the proposed technique outperforms the ED based detection even if the Tx‐Rx separation increases.

中文翻译：

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基于USRP的OFDM系统中基于能量和特征值的频谱感知算法的实验研究。

在本文中，首先，实现了使用国家仪器（NI）通用软件无线电外围设备（USRP）2942R软件定义的无线电平台的基于能量检测（ED）的频谱感知正交频分复用（OFDM）系统。可以看出，在实际情况下，ED方案在低增益（G）值下性能较差。为了克服能量检测的缺点，我们提出了基于特征值的主要用户（PU）信号检测，其中最大特征值与平均特征值之比用于检测单天线系统和多天线系统/ SISO中的PU信号以及基于多输入多输出（MIMO）的CR用户。性能指标的解析表达式（检测概率[ P _d ]）已导出。此外，实验研究表明，所提出的技术在SISO和MIMO情况下均可提供最佳（P _d）。已经观察到，即使Tx-Rx间隔增加，所提出的技术也优于基于ED的检测。