Joint Mitigation of Nonlinear RF and Baseband Distortions in Wideband Direct-Conversion Receivers
Joint Mitigation of Nonlinear RF and Baseband Distortions in Wideband Direct-Conversion Receivers
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DOI：
10.1109/tmtt.2013.2292603
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发表时间：
2014-01-01
影响因子：
4.3
通讯作者：
Thomae, Reiner
中科院分区：
文献类型：
--
作者：
Grimm, Michael;Allen, Markus;Thomae, Reiner
软件无线电技术在现代通信和雷达系统中受到越来越多的关注。部署这种技术的主要实际挑战是在RF前端实现足够的线性度和无杂散动态范围，特别是在低成本大规模生产的器件中。本文重点分析和软件定义无线电设备中的非线性失真的数字缓解，建立在宽带多载波/多无线电直接变频接收机的原理，其中广泛收集的无线电频率作为一个整体进行同相/正交下变频。首先推导出整个接收机链的总非线性失真的一个完整的行为模型，考虑到所有单独的组件，即RF低噪声放大器，同相/正交混频器，和基带同相/正交放大器的三阶非线性失真的影响。在此基础上，设计了一种自适应数字前馈线性化结构，有效地抑制了整个接收机的联合非线性失真。该方法的有效性通过广泛的仿真和实际的RF系统测量与商用软件定义的无线电平台，这显然优于现有的最先进的方法，不共同考虑RF和基带非线性验证。
Software-defined radio technology is experiencing more and more attention in modern communication and radar systems. The main practical challenge in deploying such technology is related to achieving sufficient linearity and spurious-free dynamic range in the RF front-end, especially in low-cost mass-product devices. This paper focuses on the analysis and digital mitigation of nonlinear distortion in software-define radio devices, building on wideband multicarrier/multiradio direct-conversion receiver principle where a wide collection of radio frequencies is in-phase/quadrature down-converted as a whole. A complete behavioral model for the total nonlinear distortion of the whole receiver chain is first derived, taking into account the third-order nonlinear distortion effects in all individual components, namely, RF low-noise amplifier, in-phase/quadrature mixer, and baseband in-phase/quadrature amplifiers. Stemming from this modeling, an adaptive digital feed-forward linearization structure is then developed to efficiently mitigate the joint nonlinear distortion of the whole receiver. The effectiveness of this approach is verified through extensive simulations and actual RF system measurements with a commercially available software-defined radio platform, which clearly outperforms the existing state-of-the-art methods that do not jointly consider RF and baseband nonlinearities.