基于多抽头频谱估计方法的频谱感知技术

Spectrum sensing technique based on multi-taper spectrum estimation method

认知无线电系统中,认知用户必须具备动态可靠感知与检测频谱空穴的能力。采用多载波调制可以作为认知用户频谱感知的有效实现方式。不同于传统正交频分复用OFDM(orthogonal frequency divisionmultiplex)多载波调制,提出了认知节点基于多抽头频谱估计方法的频谱感知新技术,它基于滤波器组进行实现。采用扁长型滤波器多带调制设计的多抽头频谱估计器,具有较高的频谱动态范围,可以比周期图频谱估计器更有效地估计干扰温度功率谱。通过干扰温度功率谱仿真分析,多抽头频谱估计器作为认知用户前端频谱分析器,可以准确估计干扰温度功率谱,进而实现对主用户接收机的干扰抑制。

In cognitive radio （CR） system, secondary users （SU） must be able to sense and detect spectral holes dynamically and reliably. Multi-carrier modulation technique should be adopted as an effective realization method for SU spectrum sensing in CR. Different from conventional multi-carrier modulations such as orthogonal frequency division multiplex （OFDM）, a novel spectrum sensing method based on multi-taper spectrum estimation for CR nodes was proposed and implemented by filter banks, multi-taper spectrum estimator （MTSE） designed by multi-band modulation of prolate filter has unique characteristics such as high spectral dynamic range （SDR）, thus it can be more effective than periodogram spectrum estimator （PSE） in the aspect of estimating power spectrum density （PSD） of interference temperature. Simulation and analysis of PSD of interference temperature indicate that as the SU＇s former spectrum analyzer, the estimator can estimate PSD of interference temperature accurately, and realize interference restraint at primary user （PU）＇s receiver.