Modeling and Joint Mitigation of TX and RX Nonlinearity-Induced Receiver Desensitization
Modeling and Joint Mitigation of TX and RX Nonlinearity-Induced Receiver Desensitization
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TX 和 RX 非线性引起的接收器减敏的建模和联合缓解
DOI：
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发表时间：
2017
影响因子：
4.3
通讯作者：
M. Valkama
中科院分区：
文献类型：
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作者：
A. Kiayani;L. Anttila;M. Kosunen;K. Stadius;J. Ryynänen;M. Valkama
在本文中，我们提供了在自己的接收机（RX）工作频带中出现的杂散互调失真产品的详细建模，作为共存的发射机（TX）和RX非线性与非连续载波聚合传输的结果。此外，提出了一种高效的数字前端信号处理技术，该技术可以灵活地减轻由单独或同时共存的TX和RX非线性引起的所得RX带内自干扰。该技术是基于准确地估计有效泄漏信道，该信道对TX和RX链的非线性以及PLL滤波器特性进行建模。在参数估计阶段，采用观测RX链来分别估计TX通带泄漏响应，这有助于TX和RX引起的自干扰的有效联合估计和再生。在在线数字消除中，实际发送数据与估计的信道响应结合使用，以生成整体非线性自干扰的副本，随后通过从实际观测中减去它来抑制该副本。一般来说，所提出的技术可以有效地估计和抑制位于RX频带的任意寄生子带处的自干扰。通过全面的数值模拟和实际RF测量进行的性能评估表明，该器件具有高精度和高效率的工作性能，测量的自干扰抑制高达28 dB。
In this paper, we provide detailed modeling of the spurious intermodulation distortion products appearing in the own receiver (RX) operating band as a result of coexisting transmitter (TX) and RX nonlinearities with noncontiguous carrier aggregation transmissions. Furthermore, an efficient digital front-end signal processing technique is proposed, which can flexibly mitigate the resulting RX in-band self-interference caused either by individual or simultaneously coexisting TX and RX nonlinearities. The technique is based on accurately estimating the effective leakage channel that models the nonlinearities of the TX and RX chains and the duplexer filters characteristics. In the parameter estimation stage, an observation RX chain is adopted for separately estimating the TX passband leakage response, which facilitates efficient joint estimation and regeneration of the TX- and RX-induced self-interference. In the online digital cancellation, the actual transmit data are used in conjunction with the estimated channel responses to generate a replica of the overall nonlinear self-interference, which is subsequently suppressed by subtracting it from the actual observation. In general, the proposed technique can efficiently estimate and suppress the self-interference at arbitrary spurious sub-bands located at the RX band. The performance evaluations with comprehensive numerical simulations and practical RF measurements indicate highly accurate and efficient operation, with up to 28 dB of measured self-interference suppression.