Sub-Nyquist Sampling Receiver for Overlay Cognitive Radio Users
Sub-Nyquist Sampling Receiver for Overlay Cognitive Radio Users
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DOI：
10.1109/tsp.2018.2839611
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发表时间：
2018-08
影响因子：
5.4
通讯作者：
M. Torlak;W. Namgoong
中科院分区：
文献类型：
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作者：
M. Torlak;W. Namgoong
认知无线电（CR）网络中的次用户（SU）利用主网络未充分利用的无线电频谱。在重叠CR系统中，通过停用与主用户的频带相对应的子载波以避免干扰，可以以正交频分复用或以多载波码分多址调制格式来设计发送波形。这些重叠CR波形的传输预计将非常宽带，占用高达1 GHz的带宽。由于这种宽带信号的接收需要非常高的奈奎斯特采样率，我们建议采用一个子奈奎斯特采样前端。所提出的子奈奎斯特采样接收器尽可能相干地收集所有SU信号，这些SU信号分布在整个感兴趣的频率跨度上。我们的理论分析和仿真结果表明，该接收机的性能非常接近奈奎斯特速率接收机，显着降低了复杂度。
The secondary users (SUs) in cognitive radio (CR) networks exploit the underutilized radio spectrum of the primary networks. In overlay CR systems, transmit waveforms can be designed either in orthogonal frequency-division multiplexing or in multicarrier code division multiple access modulation formats by deactivating subcarriers corresponding to primary users’ frequency bands to avoid interference. Transmissions of these overlay CR waveforms are expected to be extremely wideband, occupying up to 1 GHz of bandwidth. As reception of such wideband signals requires very high Nyquist sampling rates, we propose to employ a sub-Nyquist sampling front end. The proposed sub-Nyquist sampling receiver collects as coherently as possible all the SU signals spread across the entire frequency span of interest. Our theoretical analysis and simulation results demonstrate that the proposed receiver performs very close to the Nyquist rate receiver with significantly reduced complexity.