模拟调频电台的调制系数估计  

Modulate factor blind estimation in analog FM station

作　　者：赵汇强[1] 武春英[2] 张利强[1] 张玉萍[3] 

机构地区：[1]军械工程学院光学与电子工程系,河北石家庄050003 [2]河北科技大学信息科学与工程学院,河北石家庄050018 [3]河北科技大学理工学院,河北石家庄050035

出　　处：《河北科技大学学报》2011年第1期34-38,共5页Journal of Hebei University of Science and Technology

摘　　要：调制系数是模拟调频(FM)电台的一个重要参数,FM信号的瞬时频率是调制系数和调制信号共同作用的结果,调制系数可由瞬时频率求出。然而瞬时频率的求解精度受接收信号噪声的影响。实验证实,在信噪比高于20 dB时,由瞬时频率得到的调制系数与实际值的相对误差在1%以下。求解瞬时频率传统的办法是利用时频分析、短时傅里叶变换等方法,但这些算法的计算精度受交叉项、窗的选取或噪声等因素的影响,又由于是二维变换、计算量较大、实时性不强,所以笔者提出了使用粒子滤波算法,降低噪声影响和运算量,提高估计精度。仿真实验验证了该算法的有效性。The modulate factor is an important parameter in analog FM station.The instantaneous frequency of the FM signal is the result of module factor and FM signal working together,and the module factor can be calculated by instantaneous frequency.But the calculation precision of instantaneous frequency is easily affected by the noise of the received signal.When the SNR（Signal Noise Ratio） is higher than 20 dB,the relative error between modulate factor and real value will be lower than 1%.The common ways to calculate instantaneous frequency include： time-frequency analysis;short time Fourier transformation and so on.The calculation precision is easily affected by the factors of cross term,window choices and noise.Besides,because of using two-dimension transformation,the calculated amount is larger and the property of real-time is not so good.So a new algorithm of particle filtering is given in this paper,which can reduce the noise and operation amount and improve the precision of estimation.The simulation experiment verifies the efficiency of the algorithm.

关 键 词：FM电台 瞬时频率 调制系数 粒子滤波 

分 类 号：TN914[电子电信—通信与信息系统]