针对心磁信号工频及背景噪声干扰问题,提出了广义S变换奇异值分解(singular value decomposition,SVD)滤波方法.在离散S变换基础上,导出了广义矩阵S变换和逆变换公式.通过对采样信号进行广义S变换,调节时频分辨率,利用SVD分解方法确定有效心磁信号区域,实现自适应时频滤波.实验结果表明,该方法能有效滤除工频及背景噪声干扰,且在较少奇异值个数情况下可获得更好的滤波性能.
An adaptive technique adopting quantum genetic algorithm (QGA) for antenna impedance tuning is presented. Three examples are given with different types of antenna impedance. The frequency range of the dual standards is from 1.7 to 2.2 GHz. Simulation results show that the proposed tuning technique can achieve good accuracy of impedance matching and load power. The reflection coefficient and VSWR obtained are also very close to their ideal values. Comparison of the proposed QGA tuning method with conventional genetic algorithm based tuning method is Moreover, the proposed method can be useful for software wireless bands. also given, which shows that the QGA tuning algorithm is much faster. defined radio systems using a single antenna for multiple mobile and