电网电压采样环节会将直流偏置分量引入到电网电压输入信号中,影响同步参考坐标系锁相环SRF-PLL(synchronous reference frame-PLL)的性能。为消除直流偏置分量对锁相环性能的影响,采用自适应最小均方(least mean square,LMS)算法滤除...电网电压采样环节会将直流偏置分量引入到电网电压输入信号中,影响同步参考坐标系锁相环SRF-PLL(synchronous reference frame-PLL)的性能。为消除直流偏置分量对锁相环性能的影响,采用自适应最小均方(least mean square,LMS)算法滤除电网电压输入信号中的直流偏置分量,并添加一种便于离散化的结构产生正交信号。实验结果表明所提锁相环方法能够有效消除直流偏置分量对锁相环性能的影响,具有良好的稳态和动态性能。展开更多
A new fine carrier frequency offset estimation algorithm in Orthogonal Frequency Division Multiplexing (OFDM) system is proposed. The correlation item is the training sequence instead of the received signal in the new...A new fine carrier frequency offset estimation algorithm in Orthogonal Frequency Division Multiplexing (OFDM) system is proposed. The correlation item is the training sequence instead of the received signal in the new algorithm. Simulation results show that the performance of the new algo- rithm is 4dB-9dB better than that of Schmidl's algorithm. Coarse frequency offset estimation is also discussed in this paper, which is the improvement of Zhang's method. The estimation range using the improvement method is twice as that using the Zhang's method. Based on the hardware of the receiver and the improved algorithm, a method using Fast Fourier Transform (FFT) is proposed to implement the coarse frequency estimation. The chip area of OFDM system can be reduced by using the proposed method.展开更多
文摘电网电压采样环节会将直流偏置分量引入到电网电压输入信号中,影响同步参考坐标系锁相环SRF-PLL(synchronous reference frame-PLL)的性能。为消除直流偏置分量对锁相环性能的影响,采用自适应最小均方(least mean square,LMS)算法滤除电网电压输入信号中的直流偏置分量,并添加一种便于离散化的结构产生正交信号。实验结果表明所提锁相环方法能够有效消除直流偏置分量对锁相环性能的影响,具有良好的稳态和动态性能。
文摘A new fine carrier frequency offset estimation algorithm in Orthogonal Frequency Division Multiplexing (OFDM) system is proposed. The correlation item is the training sequence instead of the received signal in the new algorithm. Simulation results show that the performance of the new algo- rithm is 4dB-9dB better than that of Schmidl's algorithm. Coarse frequency offset estimation is also discussed in this paper, which is the improvement of Zhang's method. The estimation range using the improvement method is twice as that using the Zhang's method. Based on the hardware of the receiver and the improved algorithm, a method using Fast Fourier Transform (FFT) is proposed to implement the coarse frequency estimation. The chip area of OFDM system can be reduced by using the proposed method.
