Novel Algorithm for Active Noise Control Systems Based on Frequency Selective Filters

A novel algorithm for active noise control systems based on frequency selective filters （FSFANC） is presented in the paper. The FSFANC aims at the multi-tonal noise attenuation problem. One FSFANC system copes with one of the tonal components, and several FSFANC systems can run independently in paralld to cancel the selected multiple tones. The proposed algorithm adopts a simple structure with only two coefficients that can be explained as the real and imaginary parts of the structure to model the secondary path, and estimates the secondary path by injecting sinusoidal identification signals. Theoretical analysis and laboratory experiments show that the proposed algorithm possesses stone advantages, such as simpler structure, less computational burden, greater stability, and fast converging speed.

PERFORMANCE OF LDPC CODED FMT SYSTEMS OVER FREQUENCY SELECTIVE FADING CHANNEL

This paper proposes the Low Density Parity Check (LDPC) coded Filtered MultiTone (FMT) systems with high-order modulation for the high data rate reliable transmission over frequency selective fading channel. For the purpose of accomplishing soft input soft output iterative decoding of LDPC codes, a new soft decision metric generation method is proposed,which obviates the need of the noise variance estimation, for M-PSK/M-QAM-type high-order modulation over frequency selective fading channel. Computer simulation indicates that, there is no performance loss with our new metric, but the complexity of implementation is reduced, and that the LDPC codes are effective to improve the Bit Error Rate (BER) of FMT in frequency selective fading channel.

两个经典宏观经济关系在中国的检验

本文用中国数据检验两个经典宏观经济关系:菲利普斯曲线关系和通货膨胀—货币增长关系。我们利用CF滤波研究发现,改革开放前后这两个关系在我国的表现有很大不同。改革开放前比较反常,而改革开放后的数据基本上证实了这两个关系:失业和通货膨胀之间的替换关系只是一种短期现象,在长期这种关系不存在;货币增长和通货膨胀在长期高度相关,而在短期这种相关性并不显著。