signal n. 1.信号,暗号;信号器。 2.动机,导火线 (for)。 3.预兆,征象。 call signal 【无线电】呼号。 an alarm signal 警报(器)。 an information signal 〔美国〕暴风警报(旗)。 an international code of signals 国际通用信号。 a signal of distress =a distress signal 船只失事信号。 adj. 1.暗号的,作信号用的。 2.显著的,非常的,优越的。 a signal victory [defeat] 大胜[败]。 vt.,vi. (〔英国〕 -ll-) 发信号[警报]给(人、船等);用信号[警报]通知(暴风、危险等);用动作[手势]示意;预示。 a signaling bomb 信号弹。
This thesis presents the time domain character and frequency domain character of common used signals , including digital modulation signals and analogue modulation signals . the first method is to extract feature parameters from time domain and frequency domain . it can distinguish 2ask , 4ask , 2fsk , 4fsk , bpsk , qpsk , 16qam , 64qam and it is demonstrated by simulation data and sampled data 本文介绍了常用的通信信号(包括模拟调制样式和数字调制样式)的时域、频域特征,首先从时频域提取信号的特征参数,用于区分2ask 、 4ask 、 2fsk 、 4fsk 、 bpsk 、 qpsk 、 16qam 、 64qam这8种信号,用仿真信号和实际采样信号验证了该方法的可行性。
Chaotic switching modulation signals generated from different chaos sequences have been used to control smps . the effect of reducing the level of emi be compared . simulation results demonstrate : in the cpwm and cppm , chaos sequences generated from henon map is superior to the one generated from chua ' s circuit at lower multiples of switching frequency on reducing the level of emi ; in the ccfmfd , it has contrary results ; in the ccfmvd , chaos sequences generated from chua ' s circuit is superior to the one generated from henon map 仿真结果表明: cpwm和cppm模式下, henon映射混沌序列在较低次谐波处降低emi水平的效果要好于蔡氏电路混沌序列的效果。 ccfmfd模式则有相反的结果。对ccfmvd模式,蔡氏电路混沌序列比henon映射混沌序列降低emi水平的效果明显要好。