Interferer-Robust Compressed Sensing Receiver Based on Mixer Harmonics
Interferer-Robust Compressed Sensing Receiver Based on Mixer Harmonics
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DOI：
10.1109/dyspan.2019.8935706
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
W. Namgoong;M. Torlak
中科院分区：
文献类型：
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作者：
W. Namgoong;M. Torlak
在认知无线电（CR）的现有工作的基础假设是一个高性能的CR接收机的可用性。设计一个高效的宽带无线电，可以在广泛的频谱感测是具有挑战性的，特别是因为高水平的集成度和低功耗是必不可少的CR系统在电池供电的移动的系统。最近，基于压缩感知（CS）的传感策略已经被提出来以最小的硬件开销减少感知时间。然而，现有的CS接收机假设感兴趣的频率范围之外的信号能量是可忽略的。不幸的是，在真实的系统中，这不是一个准确的假设。由于设计宽带和高阶滤波器的困难，带外干扰在很大程度上保持不衰减，特别是那些靠近感兴趣频带边缘的干扰。现有CS接收器的问题在于它们对这些带外干扰器敏感，这些带外干扰器折叠带内并且导致显著的性能降级。本文提出了一种CS接收机，是更强大的带外干扰，这是不可避免地存在于现实的操作场景。在所提出的接收机中，多相时钟的级联利用现代硬开关混频混频器的谐波将宽带信号折叠到基带。所提出的接收机是类似于现有的多陪集接收机，但没有折叠的带外干扰。一个可能的电路实现的混频器块，电路的非理想性的影响已被量化。所提出的接收机甚至在没有带外干扰器的情况下也优于现有的CS接收机，因为与现有的接收机不同，它不会将带外噪声基底折叠到带内。在存在带外干扰器的情况下，现有的CS接收器停止工作，而所提出的接收器在很大程度上保持不受影响。
The underlying assumption in much of the existing work on cognitive radios (CRs) has been the availability of a high-performance CR receiver. Designing an efficient wideband radio that can sense over a broad spectrum is challenging, especially since high-levels of integration and low power are essential for CR systems operating in battery-powered mobile systems. Recently, sensing strategies based on compressed sensing (CS) have been proposed to reduce the sensing time at minimal hardware overhead. Existing CS receivers, however, assume that the signal energy outside the frequency range of interest is negligible. In a real system, unfortunately, this is not an accurate assumption. Because of the difficulty of designing a wideband and high-order filter, the out-of-band interferers remain largely unattenuated, especially those near the edge of the frequency band of interest. The problem with existing CS receivers is that they are sensitive to these out-of-band interferers, which fold in-band and result in significant performance degradation. This paper presents a CS receiver that is more robust to out-of-band interferers, which are inevitably present in realistic operating scenarios. In the proposed receiver, a cascade of multi-phase clocks exploit the harmonics of modern hard-switching commutating mixers to fold the wideband signal to baseband. The proposed receiver is shown to be similar to existing multi-coset receiver but without the folding of the out-of-band interferers. A possible circuit realization of the mixer block is presented, and the effects of circuit non-idealities have been quantified. The proposed receiver outperforms existing CS receiver even in the absence of out-of-band interferers, because unlike existing receivers, it does not fold the out-of-band noise floor to in-band. In the presence of out-of-band interferers, existing CS receivers cease to function while the proposed receiver remains largely unaffected.