摘要
针对未知调制类型情况下数字调制信号的载波频率估计问题,提出了一种适用于数字调制信号的载波频率估计方法。该方法利用信号的瞬时频率来估计载波频率,并通过定位非微弱信号段和中值滤波有效地抑制了噪声和调制引起的瞬时频率的波动和冲激,来提高估计精度。论述了该方法的基本原理,列出了详细的计算步骤,并给出了仿真结果。仿真结果表明,该方法在信噪比较高的情况下(≥5dB),对于各种数字调制信号,其载波频率估计精度均可接受,适合于工程的实际应用。
To estimate carrier frequency of digitally modulated signal whose modulation type is unknown, a carrier frequency estimation method for digitally modulated signal is proposed. The method estimates carrier frequency from the signal's instantaneous frequency, and improves the estimation precision by decreasing the wave and impulse of the signal's instantaneous frequency through detecting signal's better segments and median filtering. The basic principle of the method is discussed, the detailed calculation steps are given. The simulation results show that the precision is acceptable for all kinds of digitally modulated signals with the high SNRs(≥5 dB),and the method is also suited to practical engineering.
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2004年第12期1787-1789,共3页
Systems Engineering and Electronics
关键词
载波频率估计
数字调制信号
瞬时频率
中值滤波
carrier frequency estimation
digitally modulated signal
instantaneous frequency
median filtering
