您要查找的是不是：
- quadrature frequency shift modulation 正交移频键控
- frequency shift modulation system 移频调制方式
- audio frequency shift modulation 声音频率偏移调制
- Signal demodulation of automatic block with audio frequency shift modulated track circuits was implemented with phase-locked loop( PLL) technique and a singe chip microcomputer. 利用锁相环(LL)窄带跟踪特性;与单片机结合;实现自动闭塞系统移频信号解调.
- On the base of reducing the problem, this paper put forward the idea improving bonding circuit to automatic block with audio frequency shift modulated track circuit and other signal equipmemt on the Hu Hang and Zhe Gan line. 在减少自动闭塞初期故障的基础上，对沪杭、赣线移频自动闭塞与其他信号设备的结合电路，提出了改进意见和实施措施。
- frequency shift modulation 移频调制
- A Demonstration Platform for Frequency Shift Modulated Section Signal 区间移频信号演示台
- Eight information automatic block with audio frequency shift modulated track 八信息移频电源屏
- Analysis and Counter-measure of Code Losing in Audio Frequency Shift Modulated Automatic Block with Long Distance 站内长大区段移频掉码问题的分析及对策
- Current Analysis of Filament Relay for Frequency Shift Modulated 8 Code Automatic Block 8信息移频自动闭塞灯丝继电器的电流分析
- Research on the Improved Plan for 18 Information Non-insulation Frequency Shift Modulated Automatic Blocking System 18信息无绝缘移频自动闭塞系统改进方案的研究
- The chief advantage of phase shift modulation lies in its ability to encode more than one bit of data in each shift. 相移调制的主要优点是可以在一个相移变化中编码一位以上数据。
- Digital modem technology in the digital communication occupies a very important position, commonly used digital modulation are: frequency shift keying (FSK) and phase-shift keying (PSK), and so on. 数字调制解调技术在数字通信中占有非常重要的地位，常用的数字调制有：移频键控（FSK）和移相键控（PSK）等。
- Although they can use the same modulation techniques as radio or television stations, most modems use thchniques such as phase shift modulation, whch work well for digital data. 虽然可以采用与无线电和电视相同的调制技术，但大多数Modem采用适合数字数据的相移调制技术。
- The earth's rotation and its motion around the sun add an appreciable frequency shift. 地球自转与地球绕日公转产生附加的频移。
- frequency shift modulator 移频调制器
- According to the laser gain change is linear related to the frequency shift, the Doppler frequency is extracted by the signal processing. 根据激光的增益变化和频率变化成线性关系，可以对信号进行处理求出多普勒频移。
- audio frequency shift modulator 声频移频调制器
- FSK Frequency Shift Keying type of modulation 频移键控,一种调制方式
- The Brillouin frequency shift can be precisely measured by changing the local frequency and adopting narrow filter. 通过改变本地电信号的频率对信号进行扫描和窄带滤波，从而实现了布里渊频移的精确测量。
