Abstract

To promote filter bank multicarrier (FBMC) in future communication, a novel design method of nonlinear phase FIR filter (NLPFF) is proposed under the principle of constrained minimax (CMM), by which the designed filter will act as the FBMC prototype filter. In this method, the filter coefficient symmetry characteristic (FCSC) is exploited in replace of the conventional phase response error (PRE), which simplifies the establishment of phase constraint and benefits the construction of direct magnitude constraint. Consequently, the proposed constraints related to FCSC outperform the conventional constraints addressing complex frequency response errors, since the former yields a wider range of controllable PRE as well as the dramatically reduced constraint scale. Moreover, in order to restrict the sampling inter-symbol interference, the Nyquist condition (NYQ) is constrained in the frequency domain, which circumvents the initial nonconvex problem. Simulations confirm the effectiveness of the proposed method, where the FCSC can be sufficiently relaxed to improve the stopband attenuation, making this nonlinear-phase design more flexible than previous designs of FBMC prototype filter. Besides, the bit error rate test demonstrates that the designed NLPFFs are superior to the conventional PHYDYAS filter, therefore, the proposed design can certainly produce high quality prototype filter for FBMC system.

中文翻译：

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基于滤波器系数对称特性的FBMC原型滤波器的非线性相位设计

摘要

为了在未来的通信中推广滤波器组多载波（FBMC），提出了一种基于约束极大极小值（CMM）原理的非线性相位FIR滤波器（NLPFF）的设计方法，该滤波器将作为FBMC原型滤波器。该方法利用滤波器​​系数对称特性（FCSC）代替了传统的相位响应误差（PRE），简化了相位约束的建立，有利于直接幅度约束的构建。因此，与FCSC相关的拟议约束优于解决复杂频率响应误差的常规约束，因为前者可产生范围更广的可控PRE，而且约束规模大大减小。此外，为了限制采样符号间干扰，奈奎斯特条件（NYQ）受频域限制，从而避免了最初的非凸问题。仿真结果证实了所提方法的有效性，该方法可以充分放松FCSC以改善阻带衰减，从而使这种非线性相位设计比FBMC原型滤波器的先前设计更加灵活。此外，误码率测试表明所设计的NLPFF优于传统的PHYDYAS滤波器，因此，所提出的设计无疑可以为FB​​MC系统生产出高质量的原型滤波器。使这种非线性相位设计比以前的FBMC原型滤波器设计更加灵活。此外，误码率测试表明所设计的NLPFF优于传统的PHYDYAS滤波器，因此，所提出的设计无疑可以为FB​​MC系统生产出高质量的原型滤波器。与以前的FBMC原型滤波器设计相比，该非线性相位设计更加灵活。此外，误码率测试表明所设计的NLPFF优于传统的PHYDYAS滤波器，因此，所提出的设计无疑可以为FB​​MC系统生产出高质量的原型滤波器。